BERKELEY^ 
 
 LIBRARY I 
 
 UNIVERSITY OF I 
 CALIFORNIA J 
 
 EARTH 
 
 SCIENCES 
 LIBRARY 
 
GEOLOGY 
 
LONDON: PRINTED BY 
 SPOTTISWOODE AND CO., NEW-STKEET SQTJAKE 
 
 AND PARLIAMENT STREET 
 
PRINCIPLES OP GEOLOGY 
 
 OB THE 
 
 MODERN CHANGES OF THE EARTH 
 AND ITS INHABITANTS 
 
 CONSIDERED AS ILLUSTRATIVE OF GEOLOGY 
 
 BY SIR CHARLES LYELL, BART. M.A. F.R.S. 
 
 ' Vere scire est per causas scire ' BACOX 
 
 ' The stony rocks are not primeval, but the daughters of Time ' LiNN-ECS, Syst. Nat. 
 ed. 5, Stockholm, 1748, p. 219 
 
 ' Amid all the revolutions of the globe the economy of Nature has been uniform, and her 
 laws are the only things that have resisted the general movement. The rivers and the rocks, 
 the seas and the continents, have been changed in all their parts ; but the laws which direct 
 those changes, and the rules to which they are subject, have remained invariably the 
 same ' PLAYFAIR, Illustrations of the Huttonian Theory, 374 
 
 TENTH AND ENTIRELY REVISED EDITION 
 
 IN Two VOLUMES. VOL. II. 
 
 Illustrated with JJLaps, (Plates, and Woodcuts 
 
 LONDON 
 JOHN MUKKAY, ALBEMAKLE STEEET 
 
 1868 
 
 The right of translation is reserved 
 
PALEO, 
 LIBR. 
 
 Gift of C. A. Kofoid 
 
PREFACE 
 
 THE TENTH EDITION. 
 
 
 
 EAPTH 
 
 IN the Preface to the First Volume I gave a list of the dates 
 of publication of the successive editions of this treatise, as 
 well as of my ( Elements of Geology ' and my c Antiquity of 
 Man,' and pointed out the relation of these two last works 
 to the ' Principles.' 
 
 In the same Preface I gave a list of the chief additions 
 then made for the first time ; pointing out, so far as was 
 possible, the corresponding pages in the ninth edition; so 
 that readers already familiar with the earlier editions might 
 be able at once to refer to what was new. 
 
 I now subjoin a similar list of the chief alterations and 
 additions introduced for the first time into this tenth edition. 
 
 List of the Principal Additions and Corrections in the Second 
 Volume of the Tenth Edition of the 6 Principles of Geology.' 
 
 Ninth 
 Edition. 
 
 Tenth 
 Edition. 
 Vol. II. 
 
 Additions and Corrections. 
 
 Page 
 396 
 
 to 
 424 
 
 Page 
 1 
 to 
 47 
 
 Considerable additions have been made to this Twenty-sixth 
 'Chapter, on the structure of Mount Etna, in consequence 
 of my re-examination in 1857 and 1858 of this volcano, 
 which I had first visited thirty years before, in 1828. 
 The theory of a double axis of eruption is explained (p. 9), 
 and the changes in the scenery of the Val del Bove, caused 
 by the lavas of 1852, are described (p. 31). The solid 
 texture and steep original inclination of certain lavas of 
 known date are pointed out (pp. 35 & 36). The relation 
 of some ancient valleys on Etna to the former structure 
 of the mountain is considered (p. 40). 
 
VI 
 
 PEEFACE TO THE TENTH EDITION. 
 
 Ninth 
 Edition. 
 
 Tenth 
 Edition. 
 Vol. II. 
 
 Additions and Corrections. 
 
 Page 
 
 Page 
 
 Eleven new woodcuts illustrate Chapter XXVI., borrowed 
 
 
 
 chiefly from my paper on Etna, communicated to the 
 
 
 
 Royal Society in 1858. 
 
 444 
 
 69 
 
 An account is here given of the changes produced by the 
 
 
 
 recent eruption in the Gulf of Santorin in February 1806, 
 
 
 
 with a bird's-eye view of the same. 
 
 452 
 
 82 
 
 An account of the earthquake in New Zealand in 1855, and 
 
 
 to 
 89 
 
 the permanent upheaval and subsidence of land in that 
 archipelago, is given on the authority of Messrs. Roberts, 
 
 
 
 Walter Mantell, and F. A. Weld. A new fault or shift 
 
 
 
 of 9 feet in the rocks is described. A map of the region 
 
 
 
 convulsed by the same earthquake is appended. 
 
 488 
 
 135 
 
 In reference to the earthquakes in Calabria in 1783 and 
 
 
 to 
 
 1857, the origin and mode of the propagation of earth- 
 
 
 140 
 
 quake waves is treated of, and illustrated by three new 
 
 
 
 diagrams. Some account is given of Mr. Robert Mallet's 
 
 
 
 proposed method of calculating mathematically the depth 
 
 
 
 in the earth's crust from which the shocks may proceed. 
 
 494 
 
 146 
 
 Junghuhn on the truncation of the cone of Papandayang in 
 
 
 
 Java. 
 
 529 
 
 187 
 
 Recent observations made to determine whether a change 
 
 
 
 is going on in the relative level of land and sea in 
 
 
 
 Sweden. 
 
 527 
 
 192 
 
 Messrs. Gwyn Jeffreys and Torell on shells of the Glacial 
 
 
 
 Period in the Uddevalla district in Sweden. 
 
 542 
 
 208 
 
 The hypothesis of a change in the axis of rotation of the 
 
 
 
 external shell of the earth considered as a possible cause 
 
 
 
 of change of climate. 
 
 538 
 
 209 
 
 This Thirty-second Chapter has been in part re- written and 
 
 to 
 
 to 
 
 enlarged. It is shown that the old notion, that the crys- 
 
 542 
 
 213 
 
 talline rocks, whether stratified or unstratified, such as 
 
 
 
 granite and gneiss, were produced in the lower part of the 
 
 
 
 earth's crust, at the expense of a central nucleus cooling 
 
 
 
 from a state of fusion, must be given up, now that granite 
 
 
 
 is found to be of all ages, and the metamorphic rocks to 
 
 
 
 be altered sedimentary deposits implying the denudation 
 
 
 
 of a previously solidified crust. 
 
 542 
 
 225 
 
 The Thirty-third Chapter has been in great part recast. 
 
 
 to 
 
 It is shown that the latest chemical observations on the 
 
 544 
 
 234 
 
 products of recent eruptions favour the doctrine, that 
 
 
 
 large bodies of salt water gain access, during an eruption, 
 
 
 
 to the volcanic foci. The reservoirs of melted matter in 
 
 
 
 the interior, though vast, may hold a very subordinate 
 
 
 
 place in the earth's crust. 
 
 
 
 The heat supposed to be continually lost by the planet by 
 radiation into space, may perhaps be restored by solar 
 
 
 
 magnetism in connection with electricity and chemical 
 
 
 
 action. 
 
 Chap. 
 
 261 
 
 The greater part of this Thirty-fifth Chapter is new. The 
 
 xxxiv. 
 
 to 
 
 objections originally urged against Lamarck's theory of 
 
 in 
 
 283 
 
 transmutation and his replies are considered. Also the 
 
 part 
 
 
 question whether, if new species are created from time to 
 
 
 
 time, their first appearance would have been witnessed 
 
 
 
 by the naturalist. Remarks are offered on the l Vestiges 
 
PEEFACE TO THE TENTH EDITION. 
 
 vn 
 
 Xinth 
 
 Tenth 
 Edition. 
 Vol. II. 
 
 Additions and Corrections. 
 
 Page I Page 
 
 284 
 
 to 
 315 
 
 316 
 
 to 
 
 328 
 
 329 
 to 
 353 
 
 354 
 
 to 
 368 
 358 
 
 369 
 
 to 
 
 401 
 
 396 
 402 
 to 
 432 
 
 of Creation/ and on the theory of ( Natural Selection,' as 
 advocated by Mr. C. Darwin and Mr. A. Wallace. The 
 change of opinion produced by Mr. Darwin's work on 
 ' The Origin of Species ' is pointed out, and Dr. Hooker's 
 views on the formation of species in the vegetable world 
 by variation and selection are noticed. 
 
 This Thirty-sixth Chapter is for the most part new. It con- 
 tains an explanation of Mr. Darwin's views on the for- 
 mation of new races by selection, both unconscious and 
 methodical, whether of plants or animals under domesti- 
 cation. His doctrine of l Pangenesis,' or the manner in 
 which long-lost characters may be revived in the offspring 
 of cross-breeds, is also alluded to. Likewise the fact that 
 certain parts of animals or plants may be made to vary by 
 selection, while other parts of the same remain unaltered. 
 The hybridisation of plants and animals is also considered 
 in its bearing on the nature and origin of species. 
 This Thirty-seventh Chapter is also for the most part new. 
 It treats of natural as compared to artificial selection. The 
 tendency of species to multiply beyond the means of 
 subsistence, the struggle for life, and the conditions on 
 which ( the survival of the fittest ' depends, are explained. 
 The opinions of Linneeus, de Candolle, and Darwin on 
 species are compared. It is shown that alternate gene- 
 ration will not explain the mode of origin of new species. 
 Chapter Thirty-eight, on the geographical distribution of 
 species, has been re-written. The six great provinces of 
 distinct species of terrestrial mammalia are chiefly dwelt 
 upon, and the agreement of the limitation of the species 
 of birds and reptiles, and even of the invertebrate animals 
 generally, to the same regions, is pointed out. 
 Chapter Thirty-nine, on* the migration and diffusion of 
 terrestrial animals, is re -printed, with a few slight additions 
 and corrections, from the ninth edition. 
 This woodcut of the Lemming or Lapland Marmot, taken 
 from a specimen now living in the Zoological Gardens of 
 London, has been substituted for a less faithful represent- 
 ation of the same animal given in former editions. 
 The Fortieth Chapter, on the geographical distribution and 
 migration of fish, testacea, insects and plants, is for the 
 most part the same as in the ninth edition. But the 
 following additions and alterations have been made: 
 Species of marine shells and fishes on opposite sides of 
 the Isthmus of Panama, p. 370. Moths seen flying 300 
 miles from land, p. 380. Sir C. Bunbury on plants of the 
 Table-land of Brazil, p. 385. Darwin on seeds and fruits 
 immersed in salt water without injury, p. 391. Kobert 
 Brown on source of the gulf-weed or sargassum, p. 392. 
 Darwin on seeds transported by birds, p. 396. 
 The Forty-first Chapter is entirely new. It treats of insular 
 floras and faunas considered with reference to the origin 
 of species. The islands of the Eastern Atlantic, especially 
 the Madeiras and Canaries, their volcanic origin and 
 Miocene age, are first treated of, and then the extent to 
 
Vlll 
 
 PKEFACE TO THE TENTH EDITION. 
 
 Ninth 
 Edition. 
 
 Tenth 
 Edition. 
 Vol. II. 
 
 Additions and Corrections. 
 
 Page 
 
 Page 
 
 689 
 to 
 701 
 
 433 
 
 to 
 463 
 
 660 
 to 
 663 
 
 464 
 to 
 494 
 
 746 
 
 535 
 
 
 536 
 
 765 
 
 557 
 
 
 564 
 
 775 
 to 
 797 
 
 579 
 to 
 611 
 
 which the species of mammalia, birds, insects, land-shells 
 and plants, agree or do not agree with continental species. 
 The identity or non-identity, also, of species of all these 
 classes found in different archipelagos or in different 
 islands of the same archipelago, is shown to bear an un- 
 mistakable relation to the facilities enjoyed by each class 
 of crossing the ocean. The bearing of this relationship 
 on the theory of the origin of species by variation and 
 ' natural selection ' is pointed out. 
 
 The Forty-second Chapter, on the extinction of species, is 
 re-printed from the old edition with some few additions, 
 among which may be mentioned the following: Dr. 
 Hooker on extermination of plants in St. Helena, pp. 453 
 and 462. Mr. Travers on the spread of foreign plants in 
 New Zealand, p. 453. 
 
 The whole of this Forty-third Chapter, on man, considered 
 with reference to his origin and geographical distribution, 
 is new, with the exception of the first five pages. 
 
 The antiquity of the more marked human races, and the 
 coincidence of their geographical range with that of the 
 chief zoological provinces, is considered. The question 
 as to the multiple origin of man is discussed. The bear- 
 ing of the theory of progressive development and of 
 Darwin's theory of natural selection on the derivation of 
 man from the inferior animals, is treated of. 
 
 Some remarks on the submarine forest at Bournemouth, 
 on the south coast of Hampshire, are added. 
 
 Dr. Dawson's description of a submarine forest on the Bay 
 of Fundy is introduced here. 
 
 A brief sketch is given, in retrospective chronological order, 
 of the remains of man and his works which belong to the 
 ages of Bronze and Stone. Implements of the Neolithic 
 Period of the antecedent Rein-deer Period and lastly of 
 the Palaeolithic Period, are mentioned. The position of 
 flint tools of Palaeolithic age in the drift of the southern 
 coast of Hampshire and the Isle of Wight, is explained. 
 
 The age of the pottery in the upraised marine strata near 
 Cagliari, on the south coast of Sardinia, is discussed. 
 
 The Forty-ninth Chapter is re-printed from the correspond- 
 ing or concluding Chapter of the ninth edition, with some 
 corrections in the nomenclature of corals supplied by Dr. 
 Duncan, and some observations at p. 580 on the depths 
 at which different genera grow. Allusion is also made, 
 p. 609, to the large quantity of limestone in the oldest or 
 Laurentian series of rocks in Canada. 
 
 CHAELES LYELL. 
 
 73 HARLEY STREET, LONDON : 
 March 1, 1868. 
 
CONTENTS 
 
 OF 
 
 THE SECOND VOLUME. 
 BOOK II. continued. 
 
 CHAPTER XXVI. 
 
 ETNA. 
 
 External Physiognomy of Etna Lateral Cones Their successive Obliteration 
 Marine Strata at Base of Etna of Newer Pliocene Date Oldest Volcanic Rocks 
 of same Date Fossil Plants of Living Species in ancient Tuffs of Etna Val 
 Del Bove on the Eastern Flank of Etna Internal Structure of the Mountain 
 and Proofs of a Double Axis of Eruption Want of Parallelism in the ancient 
 Lavas Dikes in the Val del Bove, their Form and Composition Truncation of 
 the Great Cone Eruptions of Etna of Historical Date Eruption of Monti 
 Rossi, 1669 Scenery of the Val Del Bove Eruptions of 1811 and 1819 That 
 of 1852 Changes which it has effected in the Val Del Bove Cascades of Lava 
 in the Val di Calanna Inclined Lava of Cava Grande Flood produced by the 
 Melting of Ice in 1755 Glacier preserved by a Covering of Lava Ancient 
 Valleys of Etna Antiquity of the Cone of Etna .... PAGE 1 
 
 CHAPTER XXVII. 
 
 VOLCANIC ERUPTIONS Concluded. 
 
 Volcanic Eruption in Iceland in 1783 New Island thrown up Lava Currents of 
 Skaptar Jokul, in same Year Their immense Volume Eruption of Jorullo in 
 Mexico Humboldt's Theory of the Convexity of the Plain of Malpais Eruption 
 of Galongoon in Java Submarine Volcanos Graham Island, formed in 1831 
 Volcanic Archipelagos Submarine Eruptions in Mid Atlantic The Canaries 
 Cones thrown up in Lancerote, 1730-36 Santorin and its Volcanic Eruptions 
 Barren Island in the Bay of Bengal Mud Volcanos Mineral Composition 
 of Volcanic Products 48 
 
 CHAPTER XXVIII. 
 
 EARTHQUAKES AND THEIR EFFECTS. 
 
 Earthquakes and their Effects Deficiency of Ancient Accounts Ordinary Atmo- 
 spheric Phenomena Changes produced by Earthquakes in Modern Times 
 
CONTENTS OF THE SECOND VOLUME. 
 
 considered in Chronological Order Earthquake in New Zealand Permanent 
 Upheaval and Subsidence of Land A Fault produced in the Eocks Earth- 
 quake in Syria, 1837 Earthquakes in Chili in 1837 and 1835 Isle of Santa 
 Maria raised ten Feet Chili, 1822 Extent of Country elevated Earthquake 
 of Cutch in 1819 Subsidence in the Delta of the Indus Island of Sumbawa in 
 1815 Earthquake of Caraccas in 1812 Shocks at New Madrid in 1811 in the 
 Valley of the Mississippi PAGE 80 
 
 CHAPTER XXIX. 
 
 EARTHQUAKES OF THE EIGHTEENTH CENTURY. 
 
 Earthquakes of the Eighteenth Century Quito, 1797 Sicily, 1790 Calabria, 
 February 5, 1783 Shocks continued to the end of the Year 1786 Authorities 
 Area convulsed Geological Structure of the District Movement in the 
 Stones of two Obelisks Bounding of detached Masses into the Air Difficulty 
 of ascertaining Changes of Level Subsidence of the Quay at Messina Shift or 
 Fault in the Round Tower of Terranuova Opening and Closing of Fissures 
 Large Edifices engulfed Dimensions of New Caverns and Fissures Gra- 
 dual Closing in of Rents Derangement of River Courses --Landslips Buildings 
 transported entire to great Distances New Lakes Funnel-shaped Hollows in 
 Alluvial Plains Currents of Mud Fall of Cliffs, and Shore near Scilla inun- 
 dated State of Stromboli and Etna during the Shocks Origin and Mode of 
 Propagation of Earthquake Waves Depth of the Subterranean Source of the 
 Movement Number of Persons who perished during the Earthquake of 1783 
 Concluding Remarks 112 
 
 CHAPTER XXX. 
 EARTHQUAKES continued. 
 
 Earthquake of Java, 1772 Truncation of a lofty Cone St. Domingo, 1770 
 Lisbon, 1775 Great Area over which the Shocks extended Retreat of the 
 Sea Proposed Explanations Conception Bay, 1750 Permanent Elevation 
 Peru, 1746 Java, 1699 Rivers obstructed by Landslips Subsidence in 
 Sicily, 1693 Moluccas, 1693 Jamaica, 1692 Large Tracts engulfed Portion 
 of Port Royal Sunk Amount of Change in the last 170 years Elevation and 
 Subsidence of Land in Bay of Baise Evidence of the same afforded by the 
 Temple of Serapis 145 
 
 CHAPTER XXXI. 
 
 ELEVATION AND SUBSIDENCE OF LAND WITHOUT EARTHQUAKES. 
 
 Changes in the relative Level of Land and Sea in Regions not Volcanic Opinion 
 of Celsius that the Waters of the Baltic Sea and Northern Ocean were sinking 
 Objections raised to his Opinion Proofs of the Stability of the Sea Level in 
 the Baltic Playfair's Hypothesis that the Land was rising in Sweden Opinion 
 of Von Buch Marks cut on the Rocks Survey of these in 1820 Signs of 
 Oscillations in Level Fishing Hut buried under Marine Strata Facility of 
 appreciating slight Alterations of Level on the inner and outer Coast of Swe- 
 den Supposed Movement in opposite Directions in proceeding from the North 
 
CONTENTS OF THE SECOND VOLUME. xi 
 
 Cape Southwards to Scania Change of Level on the West Coast near Gothen- 
 burg Geological Proofs of the great Oscillation of Level since the Glacial 
 Period at Uddevalla Upraised Marine Deposits of the Western Coast of Swe- 
 den containing Shells of the Ocean, those on the Eastern Coast Shells of the 
 Baltic Whether Norway is now rising Modern Subsidence in Part of Greenland 
 Proofs afforded by these Movements of great Subterranean Changes PAGE 180 
 
 CHAPTER XXXII. 
 
 CAUSES OF EARTHQUAKES AND VOLCANOS. 
 
 Intimate Connection between the Causes of Volcanos and Earthquakes Supposed 
 Original State of Fusion of the Planet Its simultaneous and universal Fluidity 
 not proved by its Spheroidal Figure Attempt to calculate the Thickness of the 
 Solid Crust of the Earth by Precessional Motion Heat of Earth's Crust 
 increasing with the Depth, but not equally No internal Tides of supposed 
 Centfal Fluid perceptible Supposed Change of Axis of Earth's Crust Partial 
 Fluidity of the Earth's Crust most consistent with Volcanic Phenomena of the 
 Past and Present Abandonment of the Data by which the earlier Geologists 
 supported their Theory of the Pristine Fluidity of the Earth's Crust Doctrine 
 of a continual Diminution of Terrestrial and Solar Heat considered . 198 
 
 CHAPTER XXXIII. 
 
 CAUSES OF EARTHQUAKES AND VOLCANOS Continued. 
 
 Agency of Steam in Volcanic Eruptions Geysers of Iceland Expansive Power 
 of Liquid Gases Access of Salt Water, Atmospheric Air, and Fresh Water to 
 the Volcanic Foci How the successive Development of Volcanic Heat in the 
 Earth's Crust causes it to resemble a Body cooling from a general State of 
 Fusion Flexibility of the Earth's Crust Electricity and Magnetism considered 
 as Sources of Volcanic Heat Chemical Action Causes of Permanent Eleva- 
 tion and Subsidence of Land Balance of Dry Land, how preserved Recapitu- 
 lation of Chapters xxn. and xxin . . . .214 
 
 BOOK III. 
 
 CHANGES OF THE ORGANIC WORLD NOW IN PROGRESS. 
 CHAPTER XXXIV. 
 
 LAMARCK ON THE TRANSMUTATION OF SPECIES. 
 
 Division of the Subject Examination of the Question, Whether Species have a 
 real Existence in Nature ? Importance of this Question in Geology Sketch of 
 Lamarck's Arguments in favour of the Transmutation of Species, and his Con- 
 jectures respecting the Origin of existing Animals and Plants His Theory of 
 the Transformation of the Orang-outang into the Human Species . . 244 
 
xii CONTENTS OF THE SECOND VOLUME. 
 
 CHAPTER XXXV. 
 
 THEORIES AS TO THE NATURE OF SPECIES, AND DARWIN ON NATURAL 
 
 SELECTION. 
 
 Objections urged against the Theory of Transmutation and Lamarck's Eeplies 
 Mummies of Animals and Seeds of Plants from Egyptian Tombs identical in 
 Character with Species now living Linnaeus's Opinion that Species have been 
 Constant since their Creation Brocchi's Hypothesis of the Gradual Diminution 
 of Vital Power in a Species Whether if New Species are created from Time 
 to Time their First Appearance must have been witnessed by the Naturalist 
 Geoffroy St. Hilaire and Lamarck on Rudimentary Organs The Question of 
 Species as treated of in the ' Vestiges of Creation ' Mr. Alfred Wallace on the 
 Law which has regulated the Introduction of New Species Mr. Darwin on 
 Natural Selection, and Mr. Wallace -on the same Darwin's Origin of Species, 
 and the Change of Opinion which it effected Dr. Hooker's Flora of Australia, 
 and his Views as to the Origin of Species by Variation . . . PAGE 261 
 
 CHAPTER XXXVI. 
 
 VARIATION OF PLANTS AND ANIMALS UNDER DOMESTICATION VIEWED AS 
 BEARING ON THE ORIGIN OF SPECIES. 
 
 Domestic races, however Divergent, breed freely together Remote Antiquity 
 of some artificially formed Races Selection, both Unconscious and Methodi- 
 cal, very influential in forming New Races The Characters of some Races of 
 the Domesticated Pigeon of generic Value Revival of long-lost Characters in 
 the Offspring of Cross-breeds Multiple Origin of the Dog Inherited Instincts 
 Variation of the Gold Fish and Silkworm Man causes particular Parts of an 
 Animal or Plant to vary while other Parts continue unaltered Maize Cab- 
 bage Are there any Limits to the Variability of a Species ? Obedience to 
 Man under Domestication often merely a new Adaptation of a Natural Instinct 
 ' Feral ' Varieties do not revert to the exact Likeness of the Original Wild 
 Stock How far do Domestic Races differ from Wild Species in their Capacity 
 to Inter- breed ? Hybridisation of Animals and Plants Hermaphrodite 
 Plants not usually self-fertilised Whether the Distinctness of Species can be 
 tested by Hybridity Tendency of different Races of Domestic Cattle and 
 Sheep to herd apart Pallas on Domesticity eliminating Sterility Correlation 
 of Growth 284 
 
 CHAPTER XXXVII. 
 
 NATURAL SELECTON. 
 
 Natural as compared to Artificial Selection Tendency in each Species to multi- 
 ply beyond the Means of Subsistence Terms ' Selection ' and ' Survival of the 
 Fittest ' Great Number and Variety of the Natural Conditions of Existence on 
 which the Constancy or Variation of a Species depends Acclimatisation of 
 Species The Intercrossing of slight Varieties beneficial Breeding in and in 
 injurious Wild Hybrid Plants, and Opinions of Linnaeus on Protean Genera 
 De Candolle on Wild Hybrids Hybridity will not account for Special In- 
 stincts The Species of Polymorphous Genera more variable and comparatively 
 Modern Alternate Generation does not explain the Origin of New Species 316 
 
CONTENTS OF THE SECOND VOLUME. xiii 
 
 CHAPTER XXXVIII. 
 
 ON THE GEOGRAPHICAL DISTRIBUTION OF SPECIES. 
 
 Geographical Distribution of Animals Buffon on Specific Distinctness of Quad- 
 rupeds of the Old and New Worlds Doctrine of ' Natural Barriers ' Australian 
 Marsupials Geographical Relation of Extinct Fossil Forms to their nearest 
 allied Living Genera and Species Geographical Provinces of Birds according to 
 Dr. Sclater Their Applicability to Animals and Plants generally. Neotropical 
 Region Nearctic Palsearctic Ethiopian Indian Australian Wallace on 
 the Limits of the Indian and Australian Regions in the Malay Archi- 
 pelago PAGE 329 
 
 CHAPTER XXXIX. 
 
 ON THE MIGRATION AND DIFFUSION OF TERRESTRIAL ANIMALS. 
 
 Migration of Quadrupeds Migratory Instincts Drifting of Animals on Ice-Floes 
 Migration of Birds Migration of Reptiles Involuntary Agency of Man in 
 the Dispersion of Animals 354 
 
 CHAPTER XL. 
 
 ON THE GEOGRAPHICAL DISTRIBUTION AND MIGRATION OF SPECIES 
 
 continued. 
 
 Geographical Distribution and Migration of Fish Of Testacea Of Insects Moths 
 seen flying 300 Miles from Land Botanical Geography Dispersion of Plants 
 Agency of Rivers and Currents Marine Plants Sargassum or Gulf-weed 
 Agency of Animals in the Distribution of Plants Agency of Man, both volun- 
 tary and involuntary, in the Dispersion of Plants 369 
 
 CHAPTER XLI. 
 
 INSULAR FLORAS AND FAUNAS CONSIDERED WITH REFERENCE TO THE 
 ORIGIN OF SPECIES. 
 
 Volcanic Origin and Miocene Age of the Atlantic Islands Islands once formed 
 have not been since submerged, nor united with other Islands Arguments 
 against Continental Extension Map showing the great Depth of the Ocean 
 between the Volcanic Archipelagos of the Western Atlantic and the Mainland 
 Submarine Volcanic Eruptions of the present Century General Inferences to 
 be deduced from the Endemic and other Species of Animals and Plants in the 
 Atlantic Islands From Mammalia From Birds From Insects From Plants 
 From Landshells Small Number of Species of Landshells common to Madeira 
 and Porto Santo Proportion of Species common to Madeira and the Dezertas 
 Contrast of the Testaceous Fauna of the British Isles and that of the Atlantic 
 Islands Mode in which an Oceanic Island might become peopled with Land- 
 shells Variability- of Species not greater in Islands than on Continents, . 402 
 
 CHAPTER XLII. 
 
 EXTINCTION OF SPECIES. 
 
 Conditions which enable each Species of Plant to maintain its Ground agai nst 
 others Equilibrium in the Number of Species how preserved Agency of 
 
xiv CONTENTS OF THE SECOND VOLUME. 
 
 Insects in preserving this Equilibrium Devastations caused by Locusts Effect 
 of Omnivorous Animals in preserving the Equilibrium of Species Reciprocal 
 Influence of Aquatic and Terrestrial Species How Changes in Physical Geogra- 
 phy affect the Distribution of Species Extension of the Range of one Species 
 alters that of others Supposed Effects of the first Entrance of the Po]ar 
 Bear into Iceland Increase of Rein-deer imported into Iceland Influence 
 of Man in deranging the Numerical Strength of Species Indigenous Quadru- 
 peds and Birds extirpated in Great Britain Extinction of the Dodo Rapid 
 Propagation of Domestic Quadrupeds over the American Continent Power 
 of exterminating Species no Prerogative of Man Concluding Remarks on 
 Extinction PAGE 433 
 
 CHAPTER XLIII. 
 
 MAN CONSIDERED WITH REFERENCE TO HIS ORIGIN AND GEOGRAPHICAL 
 DISTRIBUTION. 
 
 Geographical Distribution of the Races of Man Drifting of Canoes to vast Dis- 
 tances Man, like other Species, has spread from a single Starting-point, or 
 limited Area Whether Man's Bodily Frame .became more stationary when his 
 Mind became more advanced Great Antiquity of the more marked Human 
 Races General Coincidence of their Range with the great Zoological Provinces 
 American-Indian common to Neoarctic and Neotropical Regions Man, an Old- 
 World Type Marked Line of Separation between Malayan and Papuan Races 
 Distinctness of Negro and European, and Question of the Multiple Origin of 
 Man Six-fingered Variety of Man as bearing on the Mutability of his Organi- 
 sation Regrowth of Supernumerary Digits when amputated These Phenomena 
 referred by Darwin to Reversion Whether Man has been degraded from a 
 higher or has risen from a lower Stage of Civilisation Gradual Diminution 
 of the Number of Languages and Races Gaudry on Intermediate Forms be- 
 tween the Upper Miocene and the Living Mammalia Relationship of Miocene 
 and Living Quadrumana Owen's Classification of Mammalia according to 
 Cerebral Development Progressive Advancement in Cerebral Capacity of the 
 Vertebrata Improvement of Man's Cerebral Conformation Whether there is 
 any Fixed Law of Progress Objections to Darwin's Theory of Natural Selection 
 considered Great Step gained if Species are shown to be developed accord- 
 ing to the ordinary Laws of Reproduction Cause of Reluctance to believe in 
 Man's Derivative Origin 464 
 
 CHAPTER XLIV. 
 
 ENCLOSING OF FOSSILS IN PEAT, BLOWN SAND, AND VOLCANIC EJECTIONS. 
 
 Division of the Subject Imbedding of Organic Remains in Deposits on emerged 
 Land Growth of Peat Site of Ancient Forests in Europe now occupied by 
 Peat Bog Iron-Ore Preservation of Animal Substances in Peat Miring of 
 Quadrupeds Bursting of the Solway Moss Imbedding of Organic Bodies and 
 Human Remains in Blown Sand Great Dismal Swamp Moving Sands of 
 African Deserts Buried Temple of Ipsambul in Egypt Dried Carcasses in the 
 Sands of the Desert Sand-dunes and Towns overwhelmed by Sand-floods 
 Imbedding of Organic and other Remains in Volcanic Formations on the 
 Land . 495 
 
CONTENTS OF THE SECOND VOLUME. xv 
 
 CHAPTER XLV. 
 
 BURYING OF FOSSILS IN ALLUVIAL DEPOSITS AND IN CAVES. 
 
 Fossils iu Alluvium Effects of sudden Inundations Terrestrial Animals most 
 abundantly preserved in Alluvium where Earthquakes prevail Marine Allu- 
 vium Buried Towns Effects of Landslips Organic Remains in Fissures and 
 Caves Form and Dimensions of Caverns - Their probable Origin Closed 
 Basins and Subterranean Rivers of the Morea Katavothra Formation of 
 Breccias with Red Cement Human Remains imbedded in Morea Schmerling 
 on Intermixture of Human Remains and Bones of Extinct Quadrupeds as 
 proving the former Co-existence of Man with those Lost Species Bone-brec- 
 cias formed in Open Fissures and Caves PAGE 511 
 
 CHAPTER XLVI. 
 
 IMBEDDING OF ORGANIC REMAINS IN SUBAQUEOUS DEPOSITS. 
 
 Division of the Subject Imbedding of Terrestrial Animals and Plants Increased 
 Specific Gravity of Wood sunk to great Depths in the Sea Drift- Timber 
 carried by the Mackenzie into Slave Lake and Polar Sea Floating Trees in the 
 Mississippi In the Gulf-stream On the Coast of Iceland, Spitzbergen, and 
 Labrador Submarine Forests Examples on Coast of Hampshire and in Bay of 
 Fundy Mineralisation of Plants Imbedding of Insects Of Reptiles Bones 
 of Birds why rare Imbedding of Terrestrial Quadrupeds by River Floods 
 Skeletons in recent Shell-marl Imbedding of Mammiferous Remains in 
 Marine Strata 524 
 
 CHAPTER XLVII. 
 
 IMBEDDING OF THE REMAINS OF MAN AND HIS WORKS IN SUBAQUEOUS 
 
 STRATA. 
 
 Drifting of Human Bodies to the Sea by River Inundations How Human Corpses 
 may be preserved in Recent Deposits Fossil Skeletons of Men Number of 
 "Wrecked Vessels Fossil Canoes, Ships, and Works of Art Chemical Changes 
 which Metallic Articles have undergone after long Submergence Imbedding 
 of Cities and Forests in Subaqueous Strata by Subsidence Earthquake of Cutch 
 in 1819 Buried Temples of Cashmere Berkeley's Arguments for the Recent 
 Date of the Creation of Man Monuments of Pre-historic Man discovered in 
 Post-tertiary Strata 541 
 
 CHAPTER XLVIII. 
 
 IMBEDDING OF AQUATIC SPECIES IN SUBAQUEOUS STRATA. 
 
 Inhumation of Freshwater Plants and Animals Shell-marl Fossilised Seed- 
 vessels and Stems of Chara Recent Deposits in American Lakes Freshwater 
 Species drifted into Seas and Estuaries Lewes Levels Alternations of Marine 
 and Freshwater Strata, how caused Imbedding of Marine Plants and Animals 
 Cetacea stranded on our Shores Littoral and Estuary Testacea swept into 
 the deep Sea Burrowing Shells Living Testacea found at considerable 
 Depths Blending of Organic Remains of different Ages .... 565 
 
 VOL. ii. a 
 
xvi CONTENTS OF THE SECOND VOLUME. 
 
 CHAPTER XLIX. 
 
 FORMATION OF CORAL REK1 S. 
 
 Growth of Coral chiefly confined to Tropical Regions Principal Genera of Coral- 
 building Zoophytes Their Rate of Growth Seldom flourish at greater Dqths 
 than Twenty Fathoms Atolls or Annular Reefs with Lagoons Maldive Isles 
 Origin of the Circular Form Cor3l Reefs not based on Submerged Volcanic 
 Craters Mr. Darwin's Theory of Subsidence in Explanation of Atolls, Encirc- 
 ling and Barrier Reefs Why the Windward Side of Atolls highest Subsidence 
 explains why all Atolls are nearly on one Level Alternate Areas of Eleva- 
 tion and Subsidence Origin of Openings into the Lagoons Size of Atolls and 
 Barrier Reefs Objection to the Theory of Subsidence considered Composition, 
 Structure, and Stratified Arrangement of Rocks now forming in Coral Reefs 
 Lime whence derived Supposed Increase of Calcareous Matter in Modern 
 Epochs controverted Concluding Remarks ..... PAGE 598 
 
LIST OF PLATES. 
 
 Directions to Binder. 
 
 PLATE V. View looking up the Val del Bove, Etna, . . To face Page 7 
 
 PLATE VI. View of the Val del Bove, as seen from above, or 
 
 from the Crater of 1819 To face Page 8 
 
 PLATE VII. View of Bay of Baise near "Naples . . . To face Page 176 
 
 ERRATA IN VOL. I. 
 
 Page 76, line 8 from foot, for ages read changes. 
 
 Page 258. For the explanation given of Figs. 11 and 12, substitute the 
 following : 
 
 Fig. 12. Here a point in St. George's Channel midway between Pembroke and 
 Wexford is taken as a centre, and we behold the greatest quantity of land existing 
 in one hemisphere. 
 
 Fig. 11. Here the centre is the antipodal point to that taken in Fig. 12, and 
 we see the greatest quantity of water existing in one hemisphere. 
 
 Page 367, line 4 from foot, for (see above, p. 211), read (see above, p. 248). 
 
 Page 534, line 8, for north-easterly read north-westerly. 
 
 Page 578, line 3 from foot, for Perry read Perrey. 
 
 Page 585, line 9 from foot, for west read east. 
 
 Page 590, line 3 from foot, for (p. 387) read (p. 586). 
 
 Page 592, line 18, for there is one, read there is no one. 
 
 Page 630, line 20, for 72 read 71 B.C. 
 
PEINCIPLES 
 
 GEOLOGY. 
 
 ottO 
 
 BOOK II. continued. 
 CHAPTEE XXYI. 
 
 ETNA. 
 
 EXTERNAL PHYSIOGNOMY OF ETNA LATERAL CONES THEIR SUCCESSIVE OBLI- 
 TERATION MARINE STRATA AT BASE OF ETNA OF NEWER PLIOCENE DATE 
 
 OLDEST VOLCANIC ROCKS OF SAME DATE FOSSIL PLANTS OF LIVING SPECIES IN 
 
 ANCIENT TUFFS OF ETNA VAL DEL BOVE ON THE EASTERN FLANK OF ETNA 
 
 INTERNAL STRUCTURE OF THE MOUNTAIN AND PROOFS OF A DOUBLE AXIS OF 
 
 ERUPTION WANT OF PARALLELISM IN THE ANCIENT LAVAS DIKES IN THE 
 
 VAL DEL BOVE, THEIR FORM AND COMPOSITION TRUNCATION OF THE GREAT 
 CONE ERUPTIONS OF ETNA OF HISTORICAL DATE ERUPTION OF MONTI ROSSI, 
 
 1669 SCENERY OF THE VAL DEL BOVE ERUPTIONS OF 1811 AND 1819 THAT 
 
 OF 1852 CHANGES WHICH IT HAS EFFECTED IN THE VAT. DEL BOVE CASCADES 
 
 OF LAVA IN THE VAL DI CALANNA INCLINED LAVA OF CAVA GRANDE FLOOD 
 PRODUCED BY THE MELTING OF ICE IN 1755 GLACIER PRESERVED BY A 
 
 COVERING OF LAVA ANCIENT VALLEYS OF ETNA ANTIQUITY OF THE CONE OF 
 
 ETNA. 
 
 EXTERNAL PHYSIOGNOMY OF ETNA. Next to Vesuvius, our 
 most authentic records relate to Etna, which rises near 
 the sea in solitary grandeur to the height of nearly 11,000 
 feet.*" The base of the cone is almost circular, and 87 English 
 miles in circumference ; but if we include the whole district 
 
 * In 18 15, Captain Smyth ascertained, by careful barometrical measurement 
 
 trigonometrically, that the height of that the height was 10, 8 7 2 feet. This 
 
 Etna was 10,874 feet. The Catanians, singular agreement of results so differ- 
 
 disappointed that theirmountain bad lost ently obtained was spoken of by Herschel 
 
 nearly 2,000 feet of the height assigned as ' a happy accident ; ' but Dr. Wol- 
 
 to it by Eecupero, refused to acquiesce laston remarked that ' it was one of 
 
 in the decision. Afterwards, in 1824, those accidents which would not hare 
 
 Sir J. Herschel, not being aware of happened to two fools.' 
 Captain Smyth's conclusions, determined 
 
 VOL. II. B 
 
ETNA. [Cn. XXVI. 
 
 over which its lavas extend, the circuit is probably twice as 
 great. 
 
 The cone is divided by nature into three distinct zones, 
 called the fertile, the woody, and the desert regions. The 
 first of these, comprising the delightful country around the 
 skirts of the mountain, is well cultivated, thickly inhabited, 
 and covered with olives, vines, corn, and fruit trees. Higher 
 up, the woody region encircles the mountain an extensive 
 forest six or seven miles in width, affording pasturage for 
 numerous flocks. The trees are of various species, the chest- 
 nut, oak, and pine being most luxuriant ; while in some tracts 
 are groves of cork and beech. Above the forest is the desert 
 region, a waste of black lava and scorise, which terminates 
 upwards in a kind of table-land, from which rises the principal 
 cone, 1,100 feet high, emitting continually steam and sul- 
 phureous vapours, and in the course of almost every century 
 several streams of lava. 
 
 Cones produced by lateral eruption. The most grand and 
 original feature in the physiognomy of Etna is the multitude 
 of minor cones which are distributed over its flanks, and 
 which are most abundant in the woody region. These, 
 although they appear but trifling irregularities when viewed 
 from a distance as subordinate parts of so imposing and 
 colossal a mountain, would, nevertheless, be deemed hills of 
 considerable altitude in almost any other region. Without 
 enumerating numerous monticules of ashes thrown out at 
 different points, there are about 200 of these secondary 
 volcanos as laid down in Yon Waltershausen's map within 
 a circuit twenty geographical miles in diameter having the 
 summit of Etna as a centre. Outside of this circular area are 
 a few other modern cones of large size, such as the double 
 hill near Nicolosi, called Monti Rossi, formed in 1669, which 
 is 450 feet high, and two miles in circumference at its base. 
 Although this hill somewhat exceeds in size Monte Nuovo, de- 
 scribed in the twenty-fourth chapter, it only ranks as a cone of 
 the second magnitude amongst those produced by the lateral 
 eruptions of Etna. Monte Minardo near Bronte, on the east 
 of the great volcano, is upwards of 700 feet in height. 
 
 On looking down from the lower borders of the desert 
 
CH. XXVI.] LATEKAL CONES OBLITEEATION OF. 3 
 
 region, these minor volcanos present us with one of the most 
 delightful and characteristic scenes in Europe. They afford 
 every variety of height and size, and are arranged in beautiful 
 and picturesque groups. However uniform they may appear 
 when seen from the sea, or the plains below, nothing can be 
 more diversified than their shape when we look from above 
 into their craters, one side of which is generally broken down. 
 There are, indeed, few objects in nature more picturesque 
 than a wooded volcanic crater. The cones situated in the 
 higher parts of the forest zone are chiefly clothed with lofty 
 pines; while those at a lower elevation are adorned with 
 chestnuts, oaks, and beech trees. 
 
 Successive obliteration of these cones. The history of the 
 eruptions of Etna, imperfect and interrupted as it is, affords 
 us, nevertheless, much insight into the manner in which a 
 large part of the mountain has successively attained its 
 present magnitude and internal structure. The cone from 
 which the eruptions at the summit now proceed, has more 
 than once been destroyed either by explosion or engulph- 
 ment, and has been as often reproduced. The great platform 
 (No. 2, Plate Y. a, b, c, fig. 79) seems to have resulted 
 from the truncation of the ancient conical mountain, the 
 uppermost part of which has disappeared during a suc- 
 cession of such catastrophes, leaving a comparatively level 
 ground from which the modern cone now springs. 
 
 By far the greater number of eruptions proceed from the 
 great crater a fig. 79, and from lateral openings in the desert 
 region. When hills are thrown up lower down or in the middle 
 zone, and project beyond the general level, they gradually 
 lose their height during subsequent eruptions ; for when lava 
 descending from the upper parts of the mountain, encounters 
 any of these hills, the stream is divided, and flows round them 
 so as to elevate the gently sloping grounds from which they 
 rise. In this manner a deduction is often made at once of 
 twenty or thirty feet, or even more, from their height. Thus, 
 one of the minor cones, called Monte Peluso, was diminished 
 in altitude by a great lava stream which encircled it in 1844 ; 
 and another current has recently taken the same course 
 yet this hill still remains 400 or 500 feet high. 
 
 B 2 
 
ETNA. 
 
 [Cn XXVI. 
 
 There is a cone called Monte Nucilla near Mcolosi, round 
 the base of which several successive currents have flowed, 
 and showers of ashes have fallen in historical times, till at 
 last, during an eruption in 1536, the surrounding plain was 
 so raised, that the top of the cone alone was left projecting 
 above the general level. Monte Nero, situated above the 
 Grotta dell' Capre, was in 1766 almost overflowed bj a 
 current: and Monte Capreolo afforded, in the year 1669, a 
 
 rig. 70. 
 
 View of Etna from the summit of the limestone platform of Primosole, 
 looking north. 
 
 a. Highest cone. 
 
 ft. Montagnuola. 
 
 c. Monte Minardo, with smaller lateral cones 
 above. 
 
 .d. Town of Licodia dei Monaci. 
 
 e. Argillaceous and sandy beds with marine 
 shells nearly all of living Mediterranean 
 species, and with associated and contempora- 
 neous volcanic rocks. 
 
 /. Escarpment of stratified subaqueous vol- 
 canic tuff, &c., north-west of Catania. 
 
 g. Town of Catania. 
 
 h, i. Dotted line expressing the highest 
 boundary along which the marine strata are 
 occasionally seen. They reach at Catira, 4 
 miles north of Catania, a height of about 1,258 
 English feet above the level of the sea. 
 
 k. Plain of Catania. 
 
 /. Limestone platform of Primosole of the 
 Newer Pliocene period. 
 
 m. La Motta di Catania. 
 
 curious example of one of the last stages of obliteration ; for 
 a lava stream, creeping along the top of a ridge which had 
 been built up by the continued superposition of successive 
 lavas, flowed directly into the crater, and nearly filled it. 
 The lava, therefore, of each new lateral cone tends to detract 
 from the relative height of lower cones above their base ; so 
 that the flanks of Etna, sloping with a gentle inclination, 
 envelope in succession a great multitude of minor volcaiios, 
 while new ones spring up from time to time. 
 
 Marine strata and volcanic rocks of Etna of Newer Pliocene 
 date. In the annexed outline of Etna and its environs, which 
 I made in 1828 from the platform of tertiary limestone of 
 Primosole, the summit of the volcano is seen 24 geogra- 
 
CH. XXVI.] MARINE STRATA OF NEWER PLIOCEXE DATE. 5 
 
 phical miles distant in a straight line. At our feet lies 
 the alluvial plain of Catania (k) 6 miles broad, through 
 which the Simeto runs, and which is bounded on the north 
 by an undulating country e, e, composed for the most part 
 of a marine tertiary deposit of Newer Pliocene age. 
 
 The district composed of it near Catania which is provin- 
 cially called ' Terra Forte,' must have emerged from beneath 
 the sea at a period of very modern date geologically speaking ; 
 for not only are almost all the fossil shells included in the 
 clays of recent species, but the argillaceous beds themselves 
 are capped at the height of nearly 1,000 feet by two deposits, 
 in one of which near the sea all the shells are of living species, 
 while the other consists of rounded pebbles of limestone and 
 other rocks evidently once brought down from the interior by 
 the Simeto and deposited in its delta, which delta was after- 
 wards uplifted together with the subjacent clay as well as the 
 neighbouring mass of Etna and the sea-coast at its base. 
 In the old alluvium here adverted to the bones of elephants 
 and other extinct mammalia have been found at several 
 points. The line h, i, expresses the level at which the 
 marine Newer Pliocene formation crops out irregularly from 
 beneath the modern streams of volcanic matter which are 
 gradually encroaching upon it and concealing it more and 
 more from view. Sometimes it cannot be traced higher than 
 600 feet, but at one place called Catira, 4 miles north of 
 Catania, the marine clays have been detected at the height 
 of 1,258 English feet above the level of the Mediterranean. 
 At that point and along the adjoining coast, as at Aci Castello 
 and at Trezza opposite the Cyclopean islands, and at Nizzeti 
 a mile and a half north-west of Trezza, the fossiliferous clays 
 are associated with contemporaneous basaltic and other 
 igneous products, the most ancient monuments of volcanic 
 action within the region of Etna. By these eruptions the 
 foundations of the great volcano may be said to have been 
 laid in the sea when the present site of Etna was a bay of the 
 Mediterranean. The fossil shells therefore found in these 
 clays are of great interest in settling the chronology of the 
 older part of the mountain. Out of 65 species which I 
 myself collected in 1828 M. Deshayes determined 4 to be 
 
6 ETNA. [Cn. XXVI. 
 
 extinct and the rest now common in the Mediterranean. 
 Phillippi obtained from the same district 76 species of 
 which only 3 were extinct, while a larger number (109) 
 from Cefali in the suburbs of Catania yielded a proportion 
 of about 6 per cent, of extinct as compared to living species. 
 A still larger collection of 142 species of shells which Dr. 
 Aradas kindly lent to me in 1858 yielded 8 per cent, of 
 extinct species."* But these results are not so inconsistent 
 as they at first appear, because all the abundant species 
 (except Buccinum semistriatum, already mentioned as the only 
 extinct shell out of 100 found in the ancient tuffs of Somma) 
 are now living in the neighbouring sea, whereas nearly all 
 the lost species are so exceedingly rare that sometimes single 
 individuals of them have alone been found. Nevertheless I 
 regard the most ancient part of Etna as somewhat older than 
 the foundations of Vesuvius, and if I were asked what relation 
 the tertiary strata near Catania bear in point of age to our 
 British formations, I should answer that they are about 
 the age of the Norwich crag. In reference therefore to the 
 Glacial Period T consider the oldest eruptions of Etna as of 
 older date than the era of greatest cold in central and 
 northern Europe. 
 
 The reader must not suppose that the marine strata with 
 the associated basaltic rocks were first formed and then 
 raised to their present height above the level of the sea, and 
 that the great subaerial cone of Etna was a superstructure of 
 later date ; for there is reason to believe that a general and 
 gradual upheaval of the foundations of Etna, together with 
 the neighbouring country, was always going on during the 
 long period of supra-marine eruptions. And this slow upward 
 movement is probably still continuing, since raised beaches 
 or sands with littoral shells of living species often retaining 
 their colour are observed at the eastern base of Etna skirting 
 the shore, and there are also lines of inland cliff cut in the 
 tertiary strata and in the volcanic tuffs bearing witness to 
 successive alterations in the relative level of sea and land. 
 
 Fossil plants of living species in ancient tuffs of Etna. We 
 
 * See 'Mode of Origin of Mount Etna,' by the Author, Phil. Trans. Part II. for 
 1858, p. 778. 
 
CH. XXVI.] VAL DEL BOVE. 7 
 
 have rarely an opportunity of determining the exact nature 
 of the vegetation which covered the mountain when some 
 of the oldest showers of volcanic ashes were poured out ; 
 but there are some stratified tuffs at Fasano near Catania 
 replete with fossil leaves which throw some light on this 
 subject. I obtained several species of land-plants from these 
 tuffs which were determined by Professor Heer to belong to 
 species now living in Sicily. Among others were the sweet 
 bay, Laurus nobilis, the common myrtle, Myrtus communis, 
 and the Mastick tree, Pistachio, lentiscus. 
 
 Val del Bove on the eastern flank of Etna. Etna, when viewed 
 whether from the north or south, is of a very symmetrical 
 form, but on its eastern side it is intersected by a deep valley 
 called the Val del Bove, the head or upper part of which is 
 bounded by a precipice between 3,000 and 4,000 feet 
 high, which begins immediately below the eastern margin 
 of that highest platform which was before mentioned as 
 having been produced by the truncation of the great cone. 
 The annexed view, Plate Y., taken from a drawing which I 
 made in November 1828, will give the reader some idea of 
 this precipice below the platform ~No. 2, which was at that 
 time covered with snow. 
 
 The great lava currents of 1811 and 1819 are seen pouring 
 down from the higher parts of the Yal del Bove, overrunning 
 the forests of the great valley, and rising up in the foreground 
 on the left with a rugged surface, on which many hillocks 
 and depressions appear, such as often characterise a lava 
 current before it has ceased to flow as well as after its 
 consolidation. 
 
 The small cone, No. 7, was formed in 1811, and was still 
 smoking when I saw it in 1828. The other small volcano 
 to the left, from which vapour is issuing, was, I believe, one 
 of those formed in 1819. 
 
 The following are the names of some of the points indi- 
 cated in the sketch : 
 
 1. Montagnuola. 5. Finocchio. 9. Musara. 
 
 2. Torre del Filosofo. 6. Capra. 10. Zocolaro. 
 
 3. Highest cone. 7- Cone of 1811. 11. Rocca di Calanna 
 
 4. Lepra. 8. Cima del Asino. 
 
8 ETNA. [Cn. XXVI. 
 
 Description of Plate VI. The second view (PI. YI.) re- 
 presents the same valley as seen from above, or looking 
 directly down the Val del Bove, from the summit of the 
 principal crater formed in 1819. * 
 
 The circular form of the Yal del Bove is well shown in this 
 view (PI. VI.). To the right and left are the lofty precipices 
 which form the southern and northern sides of the great 
 valley, and which are intersected by dikes projecting in the 
 manner afterwards to be described. In the distance appears 
 the 'fertile region' of Etna, extending like a great plain 
 along the sea-coast. 
 
 The spots particularly referred to in the plate are the 
 following : 
 
 . Cape Spartivento, in Italy, of which the 
 outline is seen in the distance. 
 
 b. The promontory of Taormino, on the 
 Sicilian coast. 
 
 c. The river Alcantra. 
 
 d. The small village of Biposto. 
 
 e. Valley of Calanna. 
 
 /. The town of Aci Reale. 
 g. Cyclopean islands, or ' Faraglioni,' in the 
 Bay of Trezza. 
 
 h. The great harbour of Syracuse. 
 
 i. The city of Catania, near which is marked 
 the course of the lava which flowed from the 
 Monti Rossi in 1669, and destroyed part of the 
 city. 
 
 t. The Lake of Lentini. 
 
 1. To the left of the view is the crater of 
 1811, which is also shown at No. 7, in Plate III. 
 
 m. Rock of Mnsara, also seen at No. 9, in 
 Plate III. 
 
 The Val del Bove is of truly magnificent dimensions, a 
 vast amphitheatre 4 or 5 miles in diameter, surrounded by 
 nearly vertical precipices, the loftiest being at the upper or 
 eastern end, where, as before stated, they are between 3,000 
 and 4,000 feet high, and the others on the north and south 
 side diminishing gradually. from that height to 500 feet as 
 they extend eastward. The feature which first strikes the 
 geologist as distinguishing the boundary cliffs of this valley, 
 is the prodigious multitude of vertical dikes which are seen 
 in all directions traversing the volcanic beds. The circular 
 form of the great chasm, and the occurrence of so many 
 dikes, amounting perhaps to several thousands in number, 
 cannot fail to recall to the mind of everyone familiar with 
 Vesuvius the phenomena of the Atrio del Cavallo, although 
 
 * This view is taken from a sketch V. ; but I conceive that it would appear 
 
 made by Mr. James Bridges, corrected in the face of the great precipice, near 
 
 after comparison with several sketches of which the smoke issuing from the cone 
 
 my own. I am unable to point out the No. 7 is made to terminate. There are 
 
 precise spot which this crater would many ledges of rock on the face of that 
 
 occupy in the view represented in Plate precipice where eruptions have occurred. 
 
CH. XXVI.] PROOFS OF DOUBLE AXIS OF ERUPTION. 9 
 
 the Yal del Bove is on a scale as far exceeding that of Somma 
 as Etna surpasses Vesuvius in magnitude. 
 
 Internal structure of the mountain and proofs of a double axis 
 of eruption. When I first examined Etna in 1828, I sup- 
 posed that the boundary walls of the great amphitheatre dis- 
 played such an arrangement of the beds as showed that the 
 structure of that part of the mountain was very different 
 from that which the escarpment of Somma exhibits. I 
 imagined that the sloping away of the strata from a central 
 axis to all points of the compass, or what has been called the 
 quaquaversal dip, was wanting in the Yal del Bove. But 
 when I revisited the same district in 1857-8,* I discovered 
 that the lower portion of the volcanic beds exposed to view in 
 the great precipices k, i, at the head of the valley h, i, Jc, of the 
 section fig. 72, page 12, dipped steeply to the west, and this 
 arrangement of the strata, together with that observed in the 
 other cliffs bounding the valley, can only be explained by 
 assuming that there was once a great centre of eruption at 
 or near the point in the annexed map (fig. 71) which I have 
 marked with a cross as indicating the axis of Trifoglietto. 
 The direction of the arrows a, 6, c, d, e, /, g, h, i, indicate the 
 various points of the compass towards which the strata have 
 been observed to be inclined. I was accompanied in 1857 by 
 Signor G. G. Gemmellaro, when we made out this quaqua- 
 versal dip, and came to the opinion that the point marked 
 with a cross or the axis of Trifoglietto had been an ancient 
 centre of eruption. f 
 
 In confirmation of this theory, Baron S. von Waltershausen 
 has observed that there is an ancient set of greenstone dikes, 
 thirteen or more in number, which radiate from the point or 
 axis alluded to and are seen traversing the surrounding 
 precipices. These greenstone dikes are distinguishable by 
 their mineral composition from those of more modern 
 doleritic lava which radiate from the present great centre of 
 eruption or the summit of Etna. This centre may be called, 
 from the modern name of the mountain, the axis of Mongi- 
 
 * See Paper on Mount Etna by the come to the same conclusion ; for that 
 
 Author, Phil. Trans. Part II. for 1858. part of his Atlas in which he announced 
 
 f* I was not then aware that Baron this opinion was not published till after 
 
 S. Von Waltershausen had previously my return to England. 
 
10 
 
 ETNA. 
 
 [Cn. XXVI. 
 
CH. XXVI.] PROOFS OF DOUBLE AXIS OF ERUPTION. 
 
 11 
 
 Description of Fig. 71. (Map of Etna, p. 10). 
 
 Ground plan of the Yal del Bove showing the dip of the beds on opposite sides of 
 the axis of Trifoglietto. 
 
 Arrows a, b, c, d, <?,/, g, h, i, showing the dip 
 of the beds in opposite directions from the 
 centre of eruption or axis of Trifoglietto. 
 
 . Arrow showing the direction of the dip of 
 the beds in the Cisterna (see also k in the 
 section fig. 72), where they are inclined 6 
 south-east, whereas the beds in the lower parts 
 of the same precipice as indicated by the arrow 
 
 b, dip in quite a different direction, or at an 
 angle of more than 20 to the west. 
 
 L Horizontal beds in the great precipice 
 above the Serra Giannicola, resting on beds of 
 trachyte and trachitic tuff and conglomerate, 
 which last dip at angles of from 20 to 28 
 Is .W. as indicated by the arrow a. 
 
 M. N. Line of section of fig. 72. 
 
 bello. In 1858, when I paid a third visit to the Val del 
 Bove, I found that there was a great thickness of beds (I, 
 of Map fig. 71), in that part of the precipice between the 
 Piano del Lago and Giannicola, which are horizontal a fact 
 perfectly reconcilable with the theory that the structure 
 of Mount Etna is due to its having been formed by the 
 pouring out of lava and scorise from two great distinct centres 
 of eruption before alluded to, viz., that of Trifoglietto and 
 that of Mongibello ; the latter having eventually obtained 
 such an ascendancy as to overwhelm the products of the 
 former, and reduce the whole mountain to one symmetrical 
 cone, broken subsequently by the great chasm of the Yal del 
 Bove on its eastern side, above described, a chasm of compa- 
 ratively modern date. The accompanying section will explain 
 the theory of the structure of Etna above alluded to, or the 
 hypothesis of a double axis by which all the dips in opposite 
 directions in the Val del Bove, apparently so complicated, 
 together with the horizontality of the beds immediately below 
 the edge of the Piano del Lago, are found to be resolv- 
 able into a very simple arrangement, such as is exemplified 
 in not a few of the great Javanese volcanos described by 
 Junghuhn. That author has particularly called attention to 
 the fact, that when there are two centres of eruption in. the 
 same volcanic mountain, there is a certain area between them, 
 which he calls a saddle, where the beds of lava, or the 
 showers of ashes, are level or horizontal. Among other 
 instances he alludes to a saddle connecting the twin cones 
 of Gede and Panggerango which is 7,870 feet high. The 
 largest of the two cones, although truncated like Etna, is 
 9,226 feet high, and the lesser cone has a deep valley on one 
 
ETNA. 
 
 [Cn. XXVI. 
 
 side comparable to the Yal 
 del Bove. In the case of 
 Etna we are unable to de- 
 cide which of the two foci 
 A or B, fig. 72, gave vent to 
 the earliest eruptions, but 
 it is clear that after B (or 
 the focus of Trifoglietto) 
 was spent, the main vent 
 of Mongibello continued in 
 full vigour, and over- 
 whelmed with its lavas 
 and scoriae the minor cone 
 d, i until it reduced the 
 whole to one slope fc, /, h. 
 Subsequently the chasm 
 called the Val del Bove, h 
 i &, was formed, chiefly I 
 presume by explosions simi- 
 lar to those which are sup- 
 posed in Yol. I. p. 630, to 
 have removed the old cen- 
 tral portion of Somma be- 
 fore the modern cone of 
 Vesuvius was built up. 
 
 The arrangement of the 
 beds seen between ~k and i, 
 fig. 72, in the great preci- 
 pice at the head of the Val 
 del Bove, is of peculiar 
 geological interest, more 
 especially the horizontality 
 of those beds of lava which 
 are shaded with a dark tint 
 immediately below Jc. In 
 the entire absence of dip 
 which they exhibit, they 
 are strikingly contrasted 
 with lower beds seen in 
 
CH. XXVI.] HOKIZONTAL BEDS OF THE VAL DEL BOVE. 13, 
 
 the same section in the Serra Giannicola, which are highly 
 inclined. In order to study the horizontal beds, I made 
 two descents of the great precipice at different points pre- 
 viously examined by very few geologists, and observed a re- 
 markable resemblance of one of the old lava currents with 
 the lava of 1669, which overflowed some level ground in 
 the neighbourhood of Catania, where there had been a rich 
 vegetation. The vegetable soil was there turned or burnt 
 into a layer of red-brick-coloured stone, reminding me of 
 the red bands which separate so many of the lavas in 
 Madeira. Midway between the top and bottom of the 
 great precipice, at a place called Teatro Grande, the ancient 
 lava current is seen, which had evidently cooled on a flat 
 surface, and the lower scoriaceous part of which reposed on 
 a red band of burnt soil, over which it had poured. Over- 
 lying the bottom, scorise was a central mass of stony lava no 
 less than forty feet thick, divided by vertical rents, so as to 
 be almost columnar, and above this again was the usual 
 upper scoriaceous and highly vesicular division of the current. 
 No hypothesis, except that of the double axis, can give even 
 a plausible explanation of the position of this powerful 
 current, which must have cooled on a flat surface. But the 
 phenomena are quite reconcilable with the former existence 
 at this point of a saddle between the cones. 
 
 When treating of Vesuvius, in the first volume, p. 633, 
 I gave the reader an account of the theory of elevation craters 
 as it has been called, to which some geologists have attri- 
 buted the high inclination of the lavas of Somma, which dip 
 outwards in all directions from a central axis. The structure 
 of Mount Etna has been referred by the same school to a 
 similar movement of upheaval, which caused all the volcanic 
 formations previously horizontal to be suddenly uplifted into 
 a mountain mass, so as to assume a conical form, the beds of 
 lava and scoriae being made to dip away in all directions 
 from the axis of upheaval. Even if it were true that the 
 alternate scoriaceous and stony beds exhibited a quaquaversal 
 dip, many unanswerable objections might be offered to the 
 above-mentioned hypothesis. Among others, I may mention 
 the impossibility of imagining that so large a proportion of the 
 
14 
 
 ETNA. 
 
 [Cn. XXVI. 
 
 dikes of different ages should be so nearly vertical as they 
 are found to be. But as I have dwelt so long on this subject 
 on a former occasion, I will merely say here, in favour of the 
 theory of eruption as opposed to that of upheaval, that one 
 cone formed by eruption may and often does embrace and bury 
 a contiguous cone of older date and of similar origin ; whereas 
 a cone of upheaval, even if we grant that the volcanic forces 
 ever give rise to such a structure, cannot be conceived to 
 envelope an older cone. 
 
 Want of parallelism in the ancient lavas. It will be useful, 
 however, to point out in detail some features in the shape 
 
 Fig. 73. 
 d 
 
 Stony layers in the northern escarpment of the Val delBove in the Serra di Orrita, 
 part of the Concazze (see Map, fig. 71), where the precipice is 1,000 feet high. 
 
 a. Vertical section of rock 40 feet. 
 6, c. Beds to the westward in the same 
 plane as the thickest part of a. 
 
 d. Same bed as a thinning out westward to 
 a thickness of 4 or 5 feet at a distance of a 
 few hundred j'ards from a. 
 
 and structure of the beds which are intersected in the cliffs 
 of the Val del Bove, in order to show that they are not uni- 
 form in thickness, and that they by no means preserve every- 
 where that perfect parallelism to each other which has been 
 ascribed to them. They present, it is true, to the eye, a 
 great appearance of regularity when viewed as a whole and 
 
 from a distance, but when 
 more closely inspected, they 
 are found to be variable, 
 both in thickness and in 
 their dip, as much so as we 
 have any right to expect in 
 
 Non-parallel beds of stony lava in the Con- curren ts which have flowed 
 cazze, or part of the northern escarpment 
 
 of the Val del Bove. d <wn the sides of a steeply 
 
 Vertical distance from a to b about 60 feet. In- sloping COne like Etna from 
 
 Fig 74. 
 
 summit. The annexed dia- 
 
 grams will explain the appearance of the lavas and scoriee 
 at many points in the north and south walls of the Yal del 
 Bove, where they are laid open to view in vertical sections. 
 
CH. XXVI.] STEATA AND BEDS OF THE VAL DEL BOVE. 
 
 lo 
 
 As the continuity of many of the beds in the boundary 
 cliffs of the Val del Bove has been thought by some to be 
 opposed to the theory 
 of their having flowed 
 in succession one over 
 the other down the 
 sloping sides of a 
 great cone, I may re- 
 mark, that provided 
 we behold a section 
 running in the same 
 direction as the ori- 
 ginal course of the 
 currents, we have 
 every reason to ex- 
 pect them to be con- 
 tinuous for several 
 miles. As to their 
 
 Beds of doleritic lava and scoriae in the Serra del 
 Solfizio, south side of the Val del Bove. 
 
 a. Bed of stony lava 12 feet thick, inclined at an angle of 10. 
 
 b. Bed of scoriae with angular fragments of scoriaceous lava 
 5 feet thick. 
 
 c. Bed of similar materials, but coarser, thinning out at d. 
 -,. ' ' e - ^ e( ^ ^ basaltic lava, 3 feet in its greatest thickness, and 
 
 dip, even ll It amount dipping at an angle of 27 (or 17 steeper than a). 
 
 fn 90 (\r ^O fVio-ra f' Fragmentary scoriaceous bed 10 feet thick, having a 
 
 (\r 
 
 similar dip with many others which underlie it. 
 
 is no reason for con- 
 cluding, as I shall show in the sequel, that they may not 
 have been originally inclined at such high angles. 
 
 I may here remark, that I saw no signs of buried lateral 
 cones laid open by 
 
 the grand sections a 
 
 exhibited in the 
 cliffs of the Val 
 del Bove. Such 
 buried cones are 
 distinctly to be 
 seen in some in- 
 land ravines and 
 in seacliffs in Ma- 
 deira, and their 
 absence in the Yal 
 del Bove implies 
 
 that the great period of lateral eruptions was subsequent 
 in date to the origin of that valley. 
 
 Curvatures of lava in the hill of Zoccolaro, at the eastern 
 extremity of the Serra del Solfizio. 
 
 a, 6, c. Three beds of lava varying in thickness from 4 to 6 feet, 
 and separated by incoherent matter. 
 
 6 thins out at I/. 
 
 a and c are 40 feet apart in the middle of this section, and come 
 within 12 and 14 feet of each other at the two extremities of the 
 same. 
 
1C 
 
 ETNA. 
 
 [Cu. XXVI. 
 
 Dikes in the Val del Bove. I have already alluded to a set 
 of dikes of greenstone or diorite, observed by Waltershausen 
 to converge in the supposed centre of eruption or axis of 
 Trifoglietto (see p. 11). A much greater number of dikes 
 or vertical walls of lava radiate from the modern centre of 
 eruption, or that of Mongibello. They consist chiefly of 
 dolerite or greystone, intermediate between trachyte and 
 basalt, the trachi-dolerites of some geologists. They vary 
 
 Fig. 77. 
 
 
 
 Dikes at the base of the Serra del Solfizio, Etna. 
 
 in. breadth from 2 to 20 feet and upwards, and usually 
 project from the face of the cliffs, as represented in the 
 annexed drawing (fig. 77). They consist of harder materials 
 than the strata which they traverse, and therefore waste 
 away less rapidly under the influence of that repeated con- 
 gelation and thawing to which the rocks in this zone of 
 Etna are exposed. The dikes are, for the most part, vertical, 
 but sometimes they run in a tortuous course through the 
 tuffs and breccias, as represented in fig. 78. 
 
 The dikes are most numerous near the head of the Yal del 
 
CH. XXVI.] 
 
 DIKES IN THE VAL DEL BOVE. 
 
 17 
 
 Fig. 78. 
 
 Bove, or near the two ancient centres of eruption before alluded 
 to as the axes of Trifoglietto and Mongibello. They continue 
 to abound throughout that zone of the mountain where 
 lateral eruptions are frequent, but below that level they 
 become extremely rare, as in the valley of Calanna, for 
 example, in which the section of the Yal del Bove is continued. 
 Still lower in the same easterly direction, as in the valley of 
 San Giacomo for example, none occur. The rarity or ab- 
 sence of dikes as we recede from the great centres of eruption, 
 is precisely what we might have expected if the vertical 
 fissures now filled with 
 solid rock were once 
 the channels which 
 gave passage to lava 
 currents. Some of the 
 dikes blend at their 
 termination upwards 
 with currents of lava, so 
 that they stop short in _ 
 
 * * Tortuous veins of lava at Punto di Gmmento, Etna. 
 
 their vertical direction, 
 
 and do not cut through the higher currents of lava which 
 
 were of a date posterior to the dikes. 
 
 We know not how large a quantity of modern lava may 
 have been poured into the bottom of the Yal del Bove, yet 
 we perceive that eruptions breaking forth near the centre of 
 Etna have already made no small progress in filling up this 
 great hollow. Even within the memory of persons now 
 living, the rocks of Musara and Capra have, as before stated, 
 lost much of their height and picturesque grandeur by the 
 piling up of recent lavas round their base, and the great 
 chasm has intercepted many streams which would otherwise 
 have deluged the fertile region below. The volcanic forces 
 are now labouring, therefore, to repair the breach caused pro- 
 bably by one or more paroxysmal eruptions of ancient date 
 on one side of the great cone ; and unless their energy should 
 decline, or a new sinking take place, they may in time efface 
 this inequality. In that event, the restored portion will 
 always be uncoiiformable to the more ancient part, yet it 
 will consist, like it, of alternating beds of lava and scorise, 
 
 VOL. II. C 
 
18 ETNA. [Cn. XXVI. 
 
 which, with all their irregularities, will have a general slope 
 from the centre and summit of Etna towards the sea. 
 
 Origin of the Val del Bove. It will be seen by the ideal 
 section given in fig. 72, p. 12, that I suppose the modern 
 centre of eruption (that of Mongibello, A,) to have over- 
 whelmed the ancient lateral cone formed by B, so as to reduce 
 the whole mountain to a symmetrical form, the present valley 
 fc, i, h having then no existence. In what manner this 
 enormous gulf was formed has been a fertile subject of con- 
 jecture. So late as the year 1822, as we shall see in the 
 next chapter, during a violent earthquake and volcanic erup- 
 tion in Java, one side of the mountain called Galongoon, 
 which was covered by a dense forest, became an enormous 
 gulf in the form of a semicircle. The new cavity was about 
 midway between the summit and the plain, and surrounded 
 by steep rocks. 
 
 It will be shown that in that instance vast quantities of 
 boiling water and mud were thrown up like a waterspout, 
 and great blocks of basalt were projected to a distance of 
 7 miles, and ashes and lapilli of the size of nuts as far 
 as 40 miles. Numerous villages 24 miles distant from the 
 centre of eruption were completely buried, implying that the 
 solid matter ejected by the explosive power of steam was 
 voluminous enough to account for the formation of the new 
 cavity, vast as were its dimensions. 
 
 It will be also seen in the thirtieth chapter, that in the 
 year 1772, Papandayang, the largest volcano in the island 
 of Java, lost 4,000 feet of its height, af the same time that 
 40 villages, spread over an area 14 miles in length and 6 in 
 breadth, were destroyed. According to the earlier accounts 
 they were engulphed, and the truncation of the cone was attri- 
 buted to subsidence ; but the subsequent investigations of 
 Junghuhn about seventy years after the explosion have shown 
 that the villages were overwhelmed by volcanic sand and 
 scoriae, under which they now lie buried ; ^and it cannot be 
 doubted that the loss of height of the great cone, attributed 
 to subsidence, was caused in great part at least by explosion. 
 The summit of Carguairazo, one of the loftiest of the Andes 
 of Quito is said to have 'fallen in' 011 July 19, 1698, and 
 
CH. XXVI] TRUNCATION OF GREAT CONE. 19 
 
 another cone of still greater altitude in the same chain, called 
 Capac Urcu, was, according to tradition, truncated a short 
 time before the conquest of America by the Spaniards. It is 
 possible that when the lava is rising to the summit of such 
 cones the foundations of parts of the volcanic structure may 
 be undermined and melted, so that one part after another of 
 the "walls of the highest crater may sink down before the 
 principal escape of gas and the ejection of scoriae takes place. 
 
 In the year 1792 a small circular tract called the Cisterna 
 (see Map, fig. 71), situated on the edge of the platform from 
 which the highest cone of Etna rises, sank down to the depth 
 of about 40 feet, leaving a chasm on all sides of which a 
 vertical section is now seen of alternating stony lavas and 
 scoriae. It is conceivable, therefore, that parts of the area 
 of the Yal del Bove may, in like manner, have fallen in 
 during earthquakes ; but I think it probable that by far the 
 greater portion of the huge cavity was caused by explosions 
 of pent-up vapours escaping from subterranean fissures, 
 during one or more lateral eruptions connected perhaps with 
 a temporary revival of the ancient focus of eruption which I 
 have called the axis of Trifoglietto. 
 
 Eruptions of Etna of historical date. Truncation of the great 
 cone. What I have hitherto said of the first existence of 
 Etna as a submarine volcano, the building up of the sub- 
 aerial part of the mountain by the pouring out of lava and 
 scoriae from two principal centres, the accompanying general 
 upheaval of the whole mass above the level of the sea, and 
 the probable origin of the Val del Bove, has been entirely 
 founded on geological inferences from the internal structure 
 of the mountain. 
 
 We may next turn to history and enquire what changes 
 are recorded to have taken place since the volcano was an 
 object of interest to the civilised world. 
 
 Etna appears to have been in activity from the earliest 
 times of tradition ; for Diodorus Siculus mentions an eruption 
 which caused a district to be deserted by the Sicani before 
 the Trojan war. Thucydides informs us, that in the sixth 
 year of the Peloponnesian War, or in the spring of the year 
 425 B. c., a lava stream ravaged the environs of Catania, and 
 
 c 2 
 
20 
 
 ETNA 
 
 [Cn. XXVI. 
 
 this he says was the third eruption which had happened in 
 Sicily since the colonisation of that island by the Greeks.* 
 The second of the three eruptions alluded to by the historian 
 took place in the year 475 B. c., and was that so poetically 
 described by Pindar, two years afterwards, in his first 
 Pythian ode : 
 
 Kitav 
 
 A' ovpavia awfx fl 
 Ni^oetro"' Airva, iravfres 
 Xiovos o^eias TiQrjva. 
 
 In these and the seven verses which follow, a graphic de- 
 scription is given of Etna, such as it appeared five centuries 
 
 Fig. 79 
 
 Truncated appearance of the summit of Etna on the north-west side, as seen from 
 near Bronte. From Sartorius von "Waltershausen's Atlas, plate 2. 
 
 a. Modern cone. 
 
 &, c. Margin of highest platform. 
 
 d. Minor cones. 
 
 before the Christian era, and such as it has been seen when 
 in eruption in modern times. The poet is only making a 
 passing allusion to the Sicilian volcano, as the mountain 
 under which Typhseus lay buried, yet by a few touches of his 
 master hand every striking feature of the scene has been 
 faithfully portrayed. We are told of ' the snowy Etna, the 
 pillar of heaven the nurse of everlasting frost, in whose deep 
 caverns lie concealed the fountains of unapproachable fire 
 a stream of eddying smoke by day a bright and ruddy flame 
 
 * Book iii., at the end. 
 
CH. XXVI.] CHANGES IN APPEARANCE OF MOUNTAIN. 21 
 
 by night ; and burning rocks rolled down with loud uproar 
 into the sea.' 
 
 Alessi in his history of Etna refers to Seneca, who, in the 
 first century of our era reminds Lucillius that mount Etna 
 had in his time lost so much of its height that it could be no 
 longer seen by boatmen from certain points whence it had 
 been previously visible. At a much later period, Falcando 
 relates that the lofty summit of Etna had fallen in in 1179, 
 and it was destroyed, according to Fazzello, for the third time 
 in 1329. Again it was engulphed for the fourth time in 
 1444, and finally the whole top of the mountain fell in in 
 1669.* The result of these and previous truncations may 
 well have produced the form of a truncated cone, represented 
 in the accompanying drawing (fig. 79). 
 
 Eruption of 1669. Monti Rossi formed. The great eruption 
 last alluded to of 1669, deserves particular attention as the 
 first noticed by scientific observers. An earthquake had 
 levelled to the ground all the houses in Nicolosi, a town 
 situated near the lower margin of the woody region, About 
 20 miles from the summit of Etna, and 10 from the sea 
 at Catania. Two gulfs then opened near that town, from 
 whence sand and scoriae were thrown up in such quantity, 
 that in the course of three or four months, a double cone was 
 formed, called Monti Kossi (or Monte Eosso) about 450 feet 
 high. But the most extraordinary phenomenon occurred at 
 the commencement of the convulsion in the plain of S. Lio. 
 A fissure six feet broad, and of unknown depth, opened with 
 a loud crash, and ran in a somewhat tortuous course to 
 within a mile of the summit of Etna. Its direction was 
 from north to south, and its length 12 miles. It emitted a 
 most vivid light. Five other parallel fissures of consider- 
 able length afterwards opened one after the other, and 
 emitted vapour, and gave out bellowing sounds which were 
 heard at the distance of 40 miles. This case seerns to 
 present the geologist with an illustration of the manner in 
 which those continuous dikes of vertical porphyry were 
 formed, which are seen to traverse some of the older lavas of 
 Etna; for the light emitted from the great rent of S. Lio 
 
 * Alessi, Storia critica dell' Eruz. dell' Etna, p. 149, 
 
22 
 
 ETNA. 
 
 [C H . XXVI. 
 
 appears to indicate that the fissure was filled to a certain 
 height with incandescent lava, probably to the height of an 
 orifice not far from Monti Rossi, which at that time opened 
 and poured out a lava current. When the melted matter in 
 such a rent has cooled, it must become a solid wall or dike, 
 intersecting the older rocks of which the mountain is com- 
 posed ; similar rents have been observed during subsequent 
 eruptions, as in 1832, when they radiated in various directions 
 from the centre of the volcano. It has been remarked by M. 
 Elie de Beaumont, that such star-shaped fractures may 
 indicate a slight upheaval of the whole of Etna. They may 
 
 
 
 Minor cones on the flanks of Etna. 
 1. Monti Rossi, rear Nicolosi, formed in Kiii!). 2. Monpileri. 
 
 be the signs of the stretching of the mass, which may thus 
 be raised gradually by a force from below.*" 
 
 The lava current of 1669, before alluded to, soon reached 
 in its course a minor cone called Monpileri, at the base of 
 which it entered a subterranean grotto, communicating with 
 a suite of those caverns which are so common in the lavas of 
 Etna. Here it appears to have melted down some of the 
 vaulted foundations of the cone, so that the whole of that hill 
 became slightly depressed and traversed by numerous open 
 fissures. 
 
 Part of Catania destroyed. The lava, after overflowing 
 fourteen towns and villages, some having a population of 
 
 * Mem. pour servir, &c., torn. iv. p. 116. 
 
CH. XXVI.] RATE OF ADVANCE OF LAVA STREAM. 23 
 
 between 3,000 and 4,000 inhabitants, arrived at length at 
 the walls of Catania. These had been purposely raised 
 to protect the city; but the burning flood accumulated 
 till it rose to the top of the rampart, which was 60 feet in 
 height, and then it fell in a fiery cascade and overwhelmed 
 part of the city. The wall, however, was not thrown down, 
 but was discovered long afterwards, by excavations made in 
 the rock by the Prince of Biscari ; so that the traveller may 
 now see the solid lava curling over the top of the rampart as 
 if still in the very act of falling. 
 
 This great current performed the first 13 miles of its 
 course in 20 days, or at the rate of 162 feet per hour, but 
 required 23 days for the last two miles, giving a velocity 
 of only 22 feet per hour ; and we learn from Dolomieu 
 that the stream moved during part of its course at the rate 
 of 1,500 feet an hour, and in others took several days to 
 cover a few yards. * When it entered the sea it was still 
 600 yards broad, and 40 feet deep. It covered some ter- 
 ritories in the environs of Catania, which had never before 
 been visited by the lavas of Etna. While moving on, its 
 surface was in general a mass of solid rock ; and its mode 
 of advancing, as is usual with lava streams, was by the 
 occasional fissuring of the solid walls. A gentleman of 
 Catania, named Pappalardo, desiring to secure the city 
 from the approach of the threatening torrent, went out with 
 a party of 50 men whom he had dressed in skins to pro- 
 tect them from the heat, and armed with iron crows and 
 hooks. They broke open one of the solid walls which flanked 
 the current near Belpasso, and immediately forth issued a 
 rivulet of melted matter which took the direction of Paterno ; 
 but the inhabitants of that town, being alarmed for their 
 safety, took up arms and put a stop to further operations. f 
 
 As another illustration of the solidity of the walls of an 
 advancing lava stream, I may mention an adventure related 
 by Recupero, who, in 1766, had ascended a small hill formed 
 of ancient volcanic matter, to behold the slow and gradual 
 
 * See Prof. J. D. Forbes, Phil. Trans., 1846, p. 155, on Velocity of Lava, 
 f Ferrara, Descriz. della Etna, p. 108. 
 
24 ETNA. [Cn. XXVI. 
 
 approach of a fiery current, 2-J miles broad; when sud- 
 denly two small threads of liquid matter issuing from a 
 crevice detached themselves from the main stream, and ran 
 rapidly towards the hill. He and his guide had just time to 
 escape when they saw the hill, which was 50 feet in height, 
 surrounded, and in a quarter of an hour melted down into the 
 burning mass, so as to flow on with it. 
 
 But it must not be supposed that this complete fusion of 
 rocky matter coming in contact with lava is of universal, or 
 even common occurrence. It probably happens when fresh 
 portions of incandescent matter come successively in contact 
 with fusible materials. In many of the dikes which intersect 
 the tuffs and lavas of Etna, there is scarcely any perceptible 
 alteration effected by heat on the edges of the horizontal 
 beds, in contact with the vertical and more crystalline mass. 
 On the site of Monpileri, one of the towns overflowed in the 
 great eruption above described, an excavation was made in 
 1 704 ; and by immense labour the workmen reached, at the 
 depth of 35 feet, the gate of the principal church, where 
 there were three statues, held in high veneration. One 
 of these, together with a bell, some money, and other articles, 
 were extracted in a good state of preservation from beneath 
 a great arch formed by the lava. It seems very extra- 
 ordinary that any works of art, not encased with tuff, like 
 those in Herculaneum, should have escaped fusion in hollow 
 spaces left open in this lava current, which was so hot at 
 Catania eight years after it had entered the town, that it was 
 impossible to hold the hand in some of the crevices. 
 
 Subterranean caverns on Etna. Mention was made of the 
 entrance of a lava stream into a subterranean grotto, whereby 
 the foundations of a hill were partly undermined. Such 
 underground passages are among the most curious features 
 on Etna, and may perhaps be caused by the sudden con- 
 version into steam of lakes or streams of water overwhelmed 
 by a fiery current. Great volumes of vapour thus produced 
 may force their way through liquid lava already coated over 
 externally with a solid crust, and may cause the sides of 
 such passages as they harden to assume a very irregular 
 outline. Near Nicolosi, not far from Monti Rossi, one of 
 
CH. XXVI.] CHANGES PRODUCED BY MODERN ERUPTIONS. 25 
 
 these great openings may be seen, called the Fossa della 
 Palomba, 625 feet in circumference at its mouth, and 78 
 deep. After reaching the bottom of this, we enter another 
 dark cavity, and then others in succession, sometimes de- 
 scending precipices by means of ladders. At length the 
 vaults terminate in a great gallery 90 feet long, and from 
 15 to 50 broad, beyond which there is still a passage, never 
 yet explored ; so that the extent of these caverns remains 
 unknown. The walls and roofs of these great vaults are com- 
 posed of rough bristling scoriae, of the most fantastic forms. 
 Changes produced by modem eruptions in the Val del Bove. 
 The change which had taken place in the aspect of several 
 parts of Etna, but especially in the Yal del Bove, between 
 my first and second visits, or between 1825 and 1857, was very 
 striking. That deep chasm is called in the provincial dialect 
 of the peasants, ' Yal di Bue,' for here the herdsman 
 
 in reducta valle mugientium 
 
 Prospectat errantes greges. 
 
 Dr. Buckland was, I believe, the first English geologist 
 Avho examined this valley with attention, and I am indebted 
 to him for having described it to me, before I visited Sicily, 
 as more worthy of attention than any single spot in that 
 island, or perhaps in Europe. 
 
 The views, Plates Y. and YI. above described, p. 7, have 
 already given the reader some idea of the scenery, looking up 
 and down the vast amphitheatre, which is between 4 and 5 
 miles in diameter. The accompanying view, fig. 81, is part of 
 a panoramic sketch, which I made from the summit of the 
 highest cone on December 1, 1828. Every part of the 
 mountain was then free from clouds, except the Yal del 
 Bove, some of the upper precipices of which, alone, were 
 visible with their large vertical and projecting dikes as seen 
 in the drawing. The crater nearest the foreground and 
 the small cone adjoining, were among those which had been 
 thrown up during the eruptions of 1810 and 1811, or eighteen 
 years before my visit. 
 
 The lavas which were poured out from near the head of 
 the Yal del Bove in those years, and subsequently in 1819, 
 
26 
 
 ETNA. 
 
 [Cn. XXVI. 
 
 flowed between some isolated rocks, called Finocchio, Capra, 
 and Musara, which are remnants of the old cone of Etna, not 
 destroyed at the time when the Yal del Bove was formed. 
 The position of these is pointed out at numbers 5, 6, and 9, 
 in Plate V. Their height had already been much reduced by 
 the flowing round them of the currents of 1811 and 1819, 
 and in 1857 I found that the lavas of 1852 had still farther 
 diminished their importance. When I first saw them as I 
 
 Fig. 81. 
 
 View from the summit of Etna into the Val del Bove. 
 
 ascended the valley, I compared them to the Trosachs in 
 the Highlands of Scotland which 
 
 Like giants stand 
 
 To sentinel enchanted land ; 
 
 though I remarked that the stern and severe grandeur of the 
 scenery which they adorned, was not such as would be 
 selected by a poet for a vale of ' enchantment.' The character 
 of the scene would accord far better with Milton's picture of 
 the infernal world ; and if we imagine ourselves to behold in 
 
CH. XXVI.] DESOLATE ASPECT OF THE EEGION. 
 
 27 
 
 motion, in the darkness of the night, one of those fiery 
 currents which have so often traversed the great valley, we 
 may well recall 
 
 yon dreary plain, forlorn and wild, 
 
 The seat of desolation, void of light, 
 
 Save what the glimmering of these livid flames 
 
 Casts pale and dreadful. 
 
 The strips of green herbage and forest land, which have 
 here and there escaped the burning lavas, serve, by contrast, 
 to heighten the desolation of the scene. When first I visited 
 the valley, nine years after the eruption of 1819, I saw 
 hundreds of trees, or rather the white skeletons of trees, on 
 the borders of the black lava, the trunks and branches being 
 
 Fig. 82. 
 
 View of the rocks Finocchio, Capra, and Musara, Val del Bove. 
 
 all leafless, and deprived of their bark by the scorching heat 
 emitted from the melted rock; an image recalling those 
 beautiful lines: 
 
 As when heaven's fire 
 
 Hath scath'd the forest oaks, or mountain pines, 
 With singed top their stately growth, though bare, 
 Stands on the blasted heath. 
 
 An unusual silence prevails throughout this region ; for 
 there are no torrents dashing from the rocks, nor any move- 
 ment of running water in this valley, such as may almost 
 invariably be heard in mountainous regions. Every drop of 
 water that falls from the heavens, or flows from the melting 
 
28 ETNA. [C H . XXVI. 
 
 ice and snow, is instantly absorbed by the porous lava ; and 
 such is the dearth of springs, that the herdsman is compelled 
 to supply his flocks, during the hot season, from stores of 
 snow laid up in hollows of the mountain during winter. 
 
 Late in the autumn, when the sun is shining, both on the 
 higher and lower parts of Etna, and on every other part of 
 Sicily, clouds of fleecy vapour often till the Val del Bove, and 
 are sometimes partially dispersed along the face of the lofty 
 precipices, causing the black outlines of the dikes to stand 
 out in picturesque relief. About midday, when the vapours 
 begin to rise, the changes of scene are varied in the highest 
 degree, different rocks being unveiled and hidden by turns, 
 and the summit of Etna often breaking through the clouds 
 for a moment with its dazzling snows, and being then as 
 suddenly withdrawn from the view. 
 
 Eruptions 0/1811 and 1819 I have alluded to the streams 
 of lava which were poured forth in 1811 and 1819. Gem- 
 mellaro, who witnessed these eruptions, informs us that the 
 great crater in 1811 first testified by its loud detonations, 
 that a column of lava had ascended to near the summit of 
 the mountain. A violent shock was then felt, and a stream 
 broke out from the side of the cone, at no great distance 
 from its apex. Shortly after this had ceased to flow, a 
 second stream burst forth at another opening, considerably 
 below the first; then a third still lower, and so on till seven 
 different issues had been thus successively formed, all lying 
 upon the same straight line. It has been supposed that 
 this line was a perpendicular rent in the internal framework 
 of the mountain, which rent was probably not produced at 
 one shock, but prolonged successively downwards, by the 
 weight, pressure, and intense heat of the internal column 
 of lava, as its surface subsided by gradual discharge through 
 each vent.* 
 
 In 1819 three large mouths or caverns opened very near 
 those which were formed in the eruptions of 1811, from 
 which flames, red-hot cinders, and sand were thrown up with 
 loud explosions. A few minutes afterwards another mouth 
 opened below, from which flames and smoke issued; and 
 
 * Scrope on Volcanos, p. 160. 
 
CH. XXVI.] ERUPTION OF AUGUST 1852. 29 
 
 finally a fifth, lower still, whence a torrent of lava flowed, 
 which spread itself with great velocity over the Val del Bove. 
 When it arrived at the precipice called the Salto della 
 Giumeiita at the head of the valley of Calanna, it poured 
 over in a cascade, and made an inconceivable crash as it was 
 dashed against the bottom. So immense was the column of 
 dust it raised by the abrasion of the tufaceous hill over which 
 the hardened mass descended, that the Catanians were in 
 great alarm, supposing a new eruption to have burst out in 
 the woody region, exceeding in violence that near the summit 
 of Etna. 
 
 Mr. Scrope observed this current in the year 1819, slowly 
 advancing down a considerable slope, at the rate of about a 
 yard an hour, nine months after its emission. The lower 
 stratum being arrested by the resistance of the ground, the 
 upper or central part gradually protruded itself, and, being 
 unsupported, fell down. This in its turn was covered by a 
 mass of more liquid lava, which swelled over it from above. 
 The current had all the appearance of a huge heap of rough 
 and large cinders rolling over and over upon itself by the 
 effect of an extremely slow propulsion from behind. The con- 
 traction of the crust as it solidified, and the friction of the 
 scoriform cakes against one another, produced a crackling 
 sound. Within the crevices a dull red heat might be seen 
 by night, and vapour issuing in considerable quantity was 
 visible by day.* 
 
 Eruption of August 1852. Of all the recorded eruptions 
 of Etna, with the exception of that of 1669 already men- 
 tioned, that which began in August 1852 and continued till 
 May of the following year, was the most remarkable for the 
 volume of lava which was poured out. In the annexed wood- 
 cut, fig. 83, 1 have given the outline of the two cones (marked 
 1852 in the Map, fig. 71) from which in that year the lava 
 issued, and in fig. 84 the course of the great stream is 
 pointed out as it flowed from those cones 6, c, through the 
 Val del Bove, and beyond to Milo in one direction, or to the 
 left, and to Zafarana on the right. Scoriae were thrown up 
 from the highest crater, and the largest of the two cones c, 
 
 * Scrope on Volcanos, p. 102. 
 
30 ETNA. [Cn. XXVI. 
 
 formed together with 6 at the base of the great precipice at 
 the head of the Val del Bove was about 500 feet high on 
 its eastern side at the end of 16 days. So great was the 
 expanse of molten matter that the whole valley when seen by 
 Dr. Giuseppe Gemmellaro at the end of August was like a sea 
 of fire. In September it reached the Salto dell a Giumenta 
 before mentioned. In its descent over the precipice it 
 sounded as if metallic and glassy substances were being 
 broken. The lava streams d d', which poured out till the 
 latter part of November, were about 2 miles broad and 6 
 long. They continued to issue with some intermissions for 
 more than nine months until May 1853. The depth of 
 single streams was from 8 to 16 feet, but when piled over 
 
 Kg- 88 
 
 The two cones formed in the Val del Bove by the eruption of 1852. 
 
 A. Lower part of Giannicola Grande. c. Lower cone called Centenario. 
 
 6. Upper or western cone. d. Commencement of current of lava of I s-V. 1 . 
 
 one another they were from 30 to 50 feet thick, and at one 
 point near the Portella or lower entrance of the valley of 
 Calanna they seemed to me to have attained a thickness of 
 150 feet. 
 
 An unusual event, and one of no small geological interest, 
 occurred some weeks after May 27th, when to all appearance 
 the flowing of lava had entirely ceased, and when all the 
 currents had become encrusted over with so firm a covering 
 of scorise that the inhabitants could walk upon them with 
 safety. Within a certain area six or seven hundred yards in 
 diameter, and situated between Zafarana and Ballo, all the 
 fruit-trees and vines were struck dead as if by lightning. 
 The ground exhaled no hot gases,and the vegetation did 
 not suffer in the space intervening between the parched-up 
 area and the recent lava, which was only a few hundred 
 yards distant. Dr. Giuseppe Gemmellaro has suggested, as 
 the most natural explanation of the phenomeno'n, that the 
 lava had gradually made its way through underground pas- 
 
CH. XXVI. ] 
 
 ITS APPEARANCE IN 1858. 
 
 sages, until coming beneath the fields alluded to, it dried up 
 the roots of the plants by its heat. It is well known (see 
 above, p. 24) that vaults and tunnels abound in many of 
 the modern lavas of Etna, and such empty spaces must some- 
 times at subsequent periods unavoidably become filled with 
 fused matter, which may then solidify under considerable 
 pressure, giving rise to masses of crystalline rock or some- 
 times perhaps to tortuous veins like those represented in 
 fig. 78, p. 17, and offering a perplexing problem to a geo- 
 logist who might obtain a section of them without having any 
 clue to the peculiar conditions under which they originated.* 
 
 Fig. 84. 
 
 Course of the lava currents through the Val del Bove in 1852-3, 
 as seen from above. 
 
 . Part of Giannicola Grande. 
 b, c, d. Same as fig. 83. 
 e . Monte Finocchio Inferiore. 
 /. -Rocca Musara. 
 
 g. Giannicola Piccola. 
 
 h, h. Concazze. 
 
 , t. Serra del Solfizio. 
 
 In 1858 I found the surface of this lava of 1853 still giving 
 out columns of white steam from numerous fumeroles espe- 
 cially after heavy rains. Near Zafarana its surface is divided 
 into longitudinal ridges rising from 30 to 70 feet above 
 the bottom of the intervening and parallel depressions. 
 
 It was a melancholy sight to behold pastures which I had 
 seen verdant in 1828 in the valley of Calanna black and 
 desolate, and the region above so deluged with the sterilising 
 products of the late eruption that there had ceased to be 
 a picturesque contrast between tracts of the old forest and 
 dark strips of modern lava. The larger part of the great 
 valley had become one monotonous desert no longer support- 
 ing any cattle, nothing to justify its original name, and with 
 scarcely a living creature to be seen, though a few goats were 
 
 Etna Paper, p. 22. 
 
32 ETXA. [Cn. XXVL 
 
 still driven up to browse on some shrubby knolls which had 
 escaped the general devastation. After passing several days 
 without seeing even a goat, the footmarks of a wolf imprinted 
 at one point on some loose volcanic sand quite surprised 
 me and made me enquire where they could still find any prey. 
 I crossed on foot a part of the new lava-field, in company 
 with Signor G. G. Gemmellaro, to the rock called Finocchio, 
 which in 1828 I had reached easily on mule-back. There 
 was now no foot-path leading to it, and we found the black 
 scoriaceous crust of the lava of 1852 bent into exceedingly 
 sharp, longitudinal ridges, separated by narrow interspaces, 
 from 20 to 40 feet deep, the sides of each ridge sloping 
 at angles of from 20 to 40 but seeming at some points 
 to be absolutely vertical. On the crests of each ridge were 
 fragments of scorifortn lava, sometimes tabular, and stick- 
 ing up edgeways, like sheets of broken ice on a Canadian 
 river, where an obstruction or 'jam' has stopped the floating 
 masses. More frequently the projecting portions of the 
 superficial crust assumed the forms of gigantic madrepores, 
 or of various animals, such as dogs and deer, or still oftener 
 the heads of elks with branching horns. The surface often 
 resembled, in all but colour, the descriptions given of coral 
 reefs ; and at one moment when my foot slipped, I had an 
 opportunity of knowing that the stony asperities could tear 
 the flesh of my hands as readily as real corals. The stones 
 on the top and sides of most of the ridges were so loose, that 
 no sooner was one of them set a-rolling, than it started a 
 number of others, until a continuous avalanche poured down 
 into the trough below ; but as we had to zigzag our way up 
 each steep ascent, there was little danger of one of us being 
 just under his companion when the torrent came down. Now 
 and then our direct march was arrested by a ridge, rendered 
 impassable by its steepness or the incoherence of the stony 
 fragments forming its crust, which obliged us to make a long 
 circuit, often with our backs turned towards our goal, the 
 hill of Finocchio. The manner in which detached blocks of 
 various shapes and sizes were occasionally poised one upon 
 another, on very narrow ridges, made us marvel that high 
 winds had not blown them down. I climbed up to some of 
 
CH. XXVI.] ANCIENT LAVA CUKRENTS CONFORMABLE. 33 
 
 them, to ascertain that they were not soldered on to the mass 
 of scoriae below ; but I found them free to move and only 
 holding on by the slight inequalities of their surface. 
 
 When at length we reached Finocchio we found it standing 
 like a rocky islet submerged up to its middle in lavas of 
 different ages, and with the fresh current of 1852 near its 
 base. The relief afforded to the eye by that oasis was very 
 great ; and although the day was cloudy, the green turf 
 enlivened by the flowers of a yellow ragwort, looked dazzling 
 by contrast with the dark surrounding desert, and the 
 autumnal crocus (colchicum autumnale), also in full bloom, 
 seemed more than ever beautiful. 
 
 The manner in which pieces of loose scorise had often rolled 
 down in great numbers from the ridges into the troughs of 
 the lava serves to show to what an extent superficial inequa- 
 lities may be reduced, or even effaced, when fresh currents 
 overflow older ones. This may partly account for the regu- 
 larity and parallelism of the successive stony lavas with their 
 upper and under scorise in the escarpments of the Val del 
 Bove ; but the chief reason why those ancient currents are 
 for the most part so conformable to each other is, I believe, 
 the steepness of the slope down which they descended ; the 
 lofty and sharp ridges above described being characteristic of 
 lavas flowing on more level ground or down slightly inclined 
 planes. When they descend very steep slopes the very 
 moderate thickness which they attain is alone sufficient to 
 preclude the possible formation of undulations like those just 
 described, which are from 10 to 30 feet or more in height. 
 
 Cascades of lava at Salto delta Giumenta. Some very 
 instructive examples are to be seen at various points on 
 Mount Etna of the external form and internal structure 
 assumed by currents of lava of known date which have flowed 
 down very steep slopes. To one of these, which was precipi- 
 tated in 1819 down a precipice which forms the head of the 
 valley of Calanna, allusion has already been made, page 29. 
 This precipice, called the Salto della Giumenta, is about 400 
 feet high and several hundred wide. In the annexed drawing, 
 fig. 85, which I made in 1828, it is seen in profile with a 
 branch of the lava of 1819 a, flowing over it. Fig. 86 is a front 
 
 VOL. II. D 
 
34 
 
 ETNA. 
 
 [Cn. XXVI. 
 
 view of the same, which. I sketched iii!858, when a much more 
 copious stream of melted matter (part of the current of 1852) 
 
 Fig. 85. A 
 
 Modern lavas, as they appeared in 1828, descending the precipice called the Salto, 
 at the head of the valley of Calanua, and flowing round the hill of that name. 
 
 A. Zoccolaro. called Salto della Giumenta, and flowing 
 
 B. Monte di Calanna. through the valley. 
 
 C. Plain at the head of the Valley of 6. Lavas of 1811 and 1819 flowing round the 
 Calanna. hill of Calanna. 
 
 a. Lava of 1819 descending the precipice 
 
 had cascaded down the same height and overflowed the plain 
 below. The greater part, however, of the same current c, like 
 
 Jfill of Zoccolaro 
 
 Fig. 86 
 
 Lava of 1852 cascading down the precipice called Salto della Giumenta. 
 
 a, a. Portions of the face of the precipice 
 composed of rocks like those of Zoccolaro and 
 Calanna, which have not been concealed by the 
 modern lavas. 
 
 6. Lava of 1819 which flowed down and en- 
 crusted the face of the precipice. 
 
 1811 which had followed the same course. 
 
 c. Lava of 1852 which cascaded over the 
 precipice. 
 
 d. The same lava overflowing the level plain 
 of the valley of Calanna. 
 
 c". Same lava flowing round the promontory 
 
 >b. Same lava passing round the pro- and covering parts of the older currents of 
 montory of Calanna, together with the lava of 1811 and 1819. 
 
CH. XXVI.] INCLINED LAVA OF CAVA GKANDE. 35 
 
 its predecessors of 1811 and 1819, turned round the promon- 
 tory formed by the Hill of Calanna, and moving right onwards 
 has been piled up. on the left side of the Valley of Calanna so 
 as to heighten its boundary wall without flowing down into it. 
 
 Both the lavas of 1819 and 1852 had been covered origi- 
 nally in every part where they congealed on the face of the 
 steep precipice with the usual scoriaceous crust. But this 
 crust, about three feet thick, had been washed off by rain 
 at several places, and had exposed to view a solid and con- 
 tinuous stony layer below. The rock is somewhat vesicular, 
 and contains crystals of felspar, augite, and olivine, with 
 some titaniferous iron. As it is inclined at angles of from 
 35 to 50, it affords a striking refutation of the doctrine that 
 stony layers can only consolidate on slopes of from 3 to 5. 
 
 Inclined lava of Gava Grande. Among other examples 
 attesting the erroneousness of the notion just alluded to, I 
 may call attention to another cascade of lava the internal 
 structure of which is still more clearly exposed to view. On 
 the eastern flank of Etna, north of Milo, is a deep and 
 narrow gulley called the Cava Grande (see Map, fig. 71), 
 which, although usually dry, has been entirely excavated 
 through successive beds of ancient lava and scoriae by the 
 waters of occasional floods, which cascade over a perpen- 
 dicular precipice of a horseshoe form, at the upper end of 
 the ravine. The torrent is gradually cutting its way back- 
 wards, and thus adding to the length of the narrow valley. 
 I witnessed, October 1857, several avalanches of sand and 
 stones loosened from the terminal cliff by the heavy rains of 
 the preceding day. The boundary walls of the opposite sides 
 of the Cava Grande are 220 feet high, in part vertical, in 
 part sloping at angles of between 38 and 65. 
 
 In the year 1689, a lava stream descended from the Val 
 del Bove in a direction nearly parallel to the Cava Grande, 
 but a portion of its left side was precipitated into the ravine 
 in the manner represented at a' a' a' in figure 87. 
 
 In addition to the retrogressive excavation of the head of 
 the ravine caused by the torrent before mentioned, the steep 
 boundary precipices are also undergoing constant waste, by 
 which means a clear vertical section of the interior structure 
 
 D 2 
 
36 
 
 ETNA. 
 
 [Cn. XXVI. 
 
 of the current a a is exposed to view as shown in the 
 diagrams, figs. 87 and 88. It is evident that when the lava 
 
 Highly inclined lava of Cava Grande. From a sketch made October 1857. 
 
 a, a. Main stream of lava of 1G89 flowing 
 eastward. 
 
 a', a'. Branch of the same lava cascading 
 northwards into the ravine called the Cava 
 Grande, with a mean inclination of 35. 
 
 b, Section of upper or scoriaceous part of 
 the current, 6 feet thick. 
 
 c, c. Solid layer of stony lava from 2J to 5 
 
 feet thick, inclined at art angle of 35 and at 
 its upper extremity at 47. 
 
 d. Scoriaceous beds forming the base of the 
 stream a', a', and underlying the stony layer c. 
 
 e,f. Cliff containing 10 ancient lava currents 
 of Etna, appearing horizontal, but being in 
 fact inclined at 7 to the east, or towards the 
 sea. 
 
 reached the edge of the precipice, fragments of the solid 
 crust with much loose scoriae first rolled down, producing a 
 talus by which the general slope of the cliff was reduced to 
 
 Supposed north and south section of the rocks at the Cava Grande near the head 
 
 of the ravine. 
 
 a, a. Lava of 1689 with lofty parallel east 
 and west ridges. 
 
 &, c, d, e, f. Same as in fig. 87. 
 
CH. XXVI.] FLOOD OF 1755 IN THE VAL DEL BOVE. 37 
 
 an angle of between 30 and 35. Near the top, however, at 
 c, part of the lava consolidated at an angle of 47, the stony 
 layer c being there only 2^ feet thick, whereas it has twice 
 that thickness where it is less inclined (viz. at 35) below. 
 The rock formed on this steep slope is as compact as our 
 ordinary ancient trap-rocks, and has the same specific 
 gravity as commonly belongs to them. It contains crystals 
 of felspar, and a small quantity of olivine. It is divided by 
 a few joints at right angles to the cooling surfaces. 
 
 Flood of 1755 in the Val del Bove. Before I allude to the 
 action of running water in excavating ravines on the flanks 
 of Etna, it may be well to mention the only instance on 
 record of a great body of water having passed from the 
 higher region of the mountain through the Val del Bove. 
 This occurred in the year 1755. An eruption had taken 
 place at the summit of the volcano, in the month of March, 
 a season when the top of the mountain was covered with 
 snow. The Canon Recupero, a good observer, and a man of 
 great sagacity, was commissioned by Charles of Bourbon, 
 king of Naples, to report on the nature and cause of the 
 catastrophe. He accordingly visited the Yal del Bove in the 
 month of June, three months after the event, and found that 
 the channel of the recent flood, nearly two miles broad, was 
 still strewed over with sand and fragments of rock to the 
 depth of 34 feet. 
 
 The volume of water in a length of one mile he estimated 
 at 16,000,000 cubic feet, and he says that it ran at the 
 rate of a mile in a minute and a half for the first twelve 
 miles. At the upper end of the Yal del Bove, all the pre- 
 existing inequalities of the ground, for a space of two miles 
 in length, and one in breadth, were perfectly levelled up and 
 made quite even, and the marks of the passage of the flood 
 were traceable from thence up the great precipice (or Balzo 
 di Trifoglietto), to the Piano del Lago, or highest platform. 
 Recupero, in his report, maintains that if all the snow on 
 Etna, which he affirms is never more than four feet deep 
 (some chasms we presume excepted), were melted in one 
 instant, which no current of lava could accomplish, it would 
 not have supplied such a volume of water. He came therefore 
 
38 ETNA. [Cii. XXVI. 
 
 to the somewhat startling conclusion, that the water was 
 vomited forth by the crater itself, and was driven out from 
 some reservoir in the interior of the mountain.* 
 
 It seems to me very unlikely that the Canon, who was on 
 the ground within three months of the date of the catas- 
 trophe, could have been mistaken in regard to the region 
 whence the waters came. His conclusions on that head seem 
 to have been legitimately deduced from the fact that the 
 wreck of the inundation was traceable continuously from the 
 sea-shore at Riposto up to the highest cone or its immediate 
 neighbourhood. I am, therefore, inclined to suspect that at 
 the time of the eruption of 1755 there was upon the summit 
 of Etna, not only the winter's snow of that year, but many 
 older layers of ice alternating with volcanic sand and lava, 
 at the foot or in the flanks of the cone, which were suddenly 
 melted by the permeation through them of hot vapours, and 
 the injection into them of melted matter. 
 
 Glacier preserved by a covering of lava. I stated in 1828,f 
 that I ascertained the fact of the existence of a glacier under 
 lava near the Casa Inglese, on the SE. side of the highest 
 cone, and that it had been quarried during the previous 
 summer, affording a supply of ice to the Catanians, at the 
 close of an unusually hot season. On returning thirty years 
 afterwards (September 1858), I found the same mass of ice, 
 of unknown extent and thickness, still unmelted. It had 
 been quarried only five years before, to the depth of four feet 
 on the very same spot. My guide told me that he had seen 
 this mass of solid ice, the bottom of which they did not 
 reach, and that it was overlaid by ten feet of sand, and the 
 sand again by lava. 
 
 Signor Mario Gemmellaro had satisfied himself in 1828, that 
 nothing but the subsequent flowing of the lava over the snow 
 could account for the position of the glacier. We may 
 suppose that, at the commencement of the eruption, a deep 
 mass of drift snow had been covered by volcanic sand 
 showered down upon it before the descent of the lava. A 
 dense stratum of this fine dust mixed with scorise is well 
 
 * Recupero, Storia dell' Etna, p. 85. 
 
 t Principles of Geology, 1st edition, p. 369. 
 
CH. XXVI.] EXISTENCE OF ICE UNDER LAVA. 39 
 
 known to be an extremely bad conductor of heat ; and the 
 shepherds in the higher regions of Etna are accustomed to 
 provide water for their flocks during summer, by strewing a 
 layer of volcanic sand a few inches thick over the snow, 
 which effectually prevents the heat of the sun from pene- 
 trating. 
 
 Suppose the mass of snow to have been preserved from 
 liquefaction until the lower part of the lava had consolidated, 
 we may then readily conceive that a glacier thus protected, 
 at the height of 10,000 feet above the level of the sea, 
 would endure as long as the snows of Mont Blanc, unless 
 melted by volcanic heat from below. When I first visited 
 the summit of the highest cone in the beginning of winter 
 (December 1st, 1828), I found the crevices in the interior 
 encrusted with thick ice, and in some cases hot vapours were 
 actually streaming out between masses of ice and the rugged 
 and steep walls of the crater. Paradoxical, therefore, as it 
 may appear, we cannot doubt that a great mass of ice was 
 preserved from melting, by the singular accident of a current 
 of lava flowing over it. 
 
 If, then, glaciers may endure for a series of years under 
 volcanic sand and lava, the store of water which Eecupero 
 speculated upon as contained somewhere in the interior of the 
 mountain, seems sufficiently accounted for. I am also now dis- 
 posed to attach more importance than when I first wrote on 
 this subject, to the tales of the mountaineers, which Recupero 
 thought worth recording. They related to him that the 
 water was boiling, that it was as salt as the sea, and that 
 it brought down with it sea-shells to the coast. Now it will 
 be seen that the hypothesis above suggested would very 
 naturally account for the water being hot, and it may have 
 been impregnated with saline matter exhaled from fumeroles 
 on the sides of the cone or from the crater itself during the 
 eruption, and these exhalations without giving to it the com- 
 position of sea- water, may have taken away its freshness. As 
 to the story of the marine shells, if the flood, after issuing 
 from the Val del Bove, cut deeply through the superficial 
 lava or the alluvium between Milo and Giarre, it may have 
 reached some of the beds of the subjacent Newer Pliocene 
 
40 ETNA. [On. XXVI. 
 
 clay, at the height of 1,000 or 1,200 feet above the sea, 
 washing out of it fossil shells of living species strong enough 
 to bear transportation as far as Biposto. 
 
 Ancient valleys of Etna. The action of volcanos is, as we 
 have already seen, characteristically intermittent even when 
 they are in a phase of frequent eruption ; but we have good 
 reason to believe that if their history could be known for 
 thousands of years, we should find that there are very long 
 periods, during which they lie dormant, and then have their 
 fires resuscitated. From Junghuhn's account of the numerous 
 cones of Java it appears that these volcanos are subject to 
 protracted periods of inaction, during which valleys, deepen- 
 ing as they descend, are eroded by running water on all their 
 sides ; at length a paroxysmal outburst occurs, by which part 
 of the cone is destroyed, and then lavas again pour out from 
 time to time. Mr. Dana, in his account of the great cones 
 of the Sandwich Islands, states, that the comparative length 
 of the periods during which any one of them has been at 
 rest may be estimated by the depth and size of the valleys 
 which furrow their sides ; but the time which such denuda- 
 tion may have occupied has often been so vast that we cannot 
 attempt, with our present knowledge, to form any conjecture 
 as to its duration. 
 
 From what was said of Vesuvius in the last chapter, the 
 reader is aware that until the year 79 of our era, it had 
 all the characters of an extinct volcano. The only part of 
 the exterior of the ancient cone which still retains that 
 physiognomy by which the whole of it must have been cha- 
 racterised before the renewal of its volcanic activity, is the 
 northern side, scarcely ever visited by travellers, and which 
 we have described as being intersected by numerous deep 
 ravines, radiating as from a central axis towards all points of 
 the compass. On ascending several of these ravines, we have 
 seen that they terminate abruptly in perpendicular precipices 
 from 60 to 300 feet in height, where in the rainy season 
 there are waterfalls.* Above the head of such precipices 
 shallow valleys continue upwards to the crest of the boundary 
 wall of the Atrio del Cavallo, and no doubt were once con- 
 
 * See Vol. I. p. 634. 
 
CH. XXVI.] PEOBABLE ORIGIN OF THE MOUNTAIN. 41 
 
 tinned to near the summit of the old cone of Somma, before 
 that mountain was truncated in the year 79. 
 
 In like manner I conceive that, long before the historical 
 era, Mount Etna may have been furrowed on all sides by 
 valleys during a long interval of comparative rest, or, perhaps, 
 a total suspension of eruptions. 
 
 The vast deposits of alluvial matter, more than 100 feet 
 thick, which are seen along the coast eastward of the Val del 
 Bove, between Giarre and Mangaiio, and which may some- 
 times be traced up to the height of 400 feet, attest the 
 enormous amount of erosion which the eastern flanks of 
 Etna have undergone at a remote period. 
 
 At length one or more paroxysmal outbreaks, to which the 
 Yal del Bove may have owed its origin, ushered in a period 
 of renewed activity to which the lateral cones are principally 
 due. The lavas pouring out successively on the northern, 
 western, and southern flanks obliterated all the ancient 
 valleys on those three sides, and would have done the same 
 on the eastern flank of the cone had they not been inter- 
 cepted in their course by that huge chasm, the Val del Bove, 
 which they have already, in great part, filled up. Three 
 valleys or ravines, which have escaped obliteration, deserve 
 notice as bearing the same relation to the margin of the Yal 
 del Bove which the valleys on the north of Vesuvius (those of 
 the Casa delT Acqua and others, described at page 634, 
 Vol. I.) bear to the Atrio del CavaUo. These three valleys 
 on the south-east side of Etna are the Valle del Tripodo, the 
 Valle dei Zappini, and the Valle di Calanna, the position of 
 which will be seen in the Map, fig. 71, p. 10. The first of them, 
 the Valle del Tripodo, although not difficult of access from 
 Zafarana, is scarcely ever visited by travellers. It is a beau- 
 tiful, wooded-alpine ravine down which a torrent flows. On 
 reaching the head of this ravine, or the col which divides it 
 from the Val del Bove, a truly splendid view is obtained of 
 all the grand features of that vast amphitheatre before de- 
 scribed. Although the col is no less than 7,000 feet high 
 above the level of the sea, it forms the lowest part of a 
 deep notch in the southern escarpment of the Val del Bove 
 or the Serra del Solfizio. (See Map, fig. 71.) The depth of the 
 
42 ETNA. [Cn. XXVI. 
 
 gap must be great as it enables an observer, looking at Etna 
 from a vessel at sea off Aci Castello, to get a view of the Yal 
 del Bove through the opening. This notch is a section of a 
 ravine of denudation once continuous with the Valle del 
 Tripodo, which furrowed the old cone before the Val del 
 Bove was formed. 
 
 The second valley, called c dei Zappini,' runs parallel to the 
 former, and is similar in its geological features though less 
 grand. The torrents that drain both of them are swallowed 
 up at their lower end in the holes and grottoes of the great 
 lava current of 1792, which, flowing down from a different 
 and higher part of Etna, crossed the channels of these 
 torrents and blocked up the ravines in which they flow. 
 
 The third valley, that of Calanna before alluded to, is the 
 most interesting because at its upper end we find the preci- 
 pice before described, figs. 85 and 86, p. 34, over which the 
 modern lavas of 1819 and 1852 have cascaded. There can 
 be no doubt that this precipice, the Salto della Giurnenta, was 
 the site of a waterfall when a river flowed down from the 
 ancient cone, before the origin of the Val del Bove. The 
 space between the hills of Zoccolaro and Calanna indicates 
 the place of the upper valley, while the Salto was formed by 
 the river cutting its way backwards after the manner of the 
 stream in the Cava Grande before described, p. 35, or of the 
 retrograding torrents of Vesuvius, or, to compare small things 
 with great, the river Niagara at its falls. 
 
 If Vesuvius continues to be as active as it has been for the 
 last eighteen centuries, its lavas may one day top the crest 
 of the Atrio and cascade over the precipices at the head of 
 the Casa del' Acqua and the Fosso di Cancharoni, in the same 
 way as the Etnean streams of 1819 and 1852 have cascaded 
 down the Salto della Giumenta. 
 
 Antiquity of the cone of Etna. It was before remarked (Vol. 
 I. p. 91) that confined notions in regard to the quantity of 
 past time have tended, more than any other prepossessions, 
 to retard the progress of sound theoretical views in geology; 
 the inadequacy of our conceptions of the earth's antiquity 
 having cramped the freedom of our speculations in this 
 science, very much in the same way as a belief in the exist- 
 
CH. XXVI.] PKOBABLE AGE OF THE MOUNTAIN. 43 
 
 ence of a vaulted firmament once retarded the progress of 
 astronomy. It was not until Descartes assumed the indefinite 
 extent of the celestial spaces, and removed the supposed 
 boundaries of the universe, that just opinions began to be 
 entertained of the relative distances of the heavenly bodies ; 
 and until we habituate ourselves to contemplate the possi- 
 bility of an indefinite lapse of ages having been comprised 
 within each of the modern periods of the earth's history, we 
 shall be in danger of forming most erroneous and partial 
 views in geology. 
 
 If history had bequeathed to us a faithful record of the 
 eruptions of Etna, and 100 other of the principal active 
 volcanos of the globe, during the last 3,000 years, if we had 
 an exact account of the volume of lava and matter ejected 
 during that period, and the times of their production, we 
 might, perhaps, be able to form a correct estimate of the 
 average rate of the growth of a volcanic cone. For we might 
 thus obtain a mean result by the comparison of the eruptions 
 of so great a number of vents, however irregular might be 
 the development of the igneous action in any one of them, if 
 contemplated singly during a brief period. 
 
 It would be necessary to balance protracted periods of in- 
 action against the occasional outburst of paroxysmal explo- 
 sions. Sometimes we should have evidence of a repose of 
 seventeen centuries, like that which was interposed in Ischia, 
 between the end of the fourth century B. c. and the beginning 
 of the fourteenth century of our era.* Occasionally a tre- 
 mendous eruption like that of Jorullo or that of Papandayang 
 and others alluded to at page 11, would be recorded, giving 
 rise at once to a new mountain, or to the truncation of an 
 ancient cone, or to some vast lateral cavity like the Yal del 
 Bove. But the comparative rarity of such catastrophes 
 exalts our conception of the great duration of the intervals 
 of rest which occur between eras of paroxysmal violence. 
 
 If we desire to approximate to the age of Etna, we ought 
 first to obtain some data in regard to the thickness of matter 
 which has been added during the historical era, and then 
 endeavour to estimate the time required for the accumulation 
 
 * See Vol. I. p. 606. 
 
44 ETNA. [CH. XXVI. 
 
 of such, alternating lavas and beds of sand and scoriae as are 
 superimposed upon each other in the Val del Bove ; after- 
 wards we should try to deduce, from observations on other 
 volcanos, the more or less rapid increase of burning moun- 
 tains in all the different stages of their growth. 
 
 Although it is possible that some of the ancient eruptions 
 of which the products are seen in the walls of the Yal del 
 Bove were on as grand a scale as those of our own time or 
 even grander, yet we should in vain seek for evidence that 
 any one of those ancient currents equalled in volume the 
 lavas of 1669 or those of 1852. 
 
 There is a considerable analogy between the mode of in- 
 crease of a volcanic cone and that of trees of exogenous growth. 
 These trees augment, both in height and diameter, by the 
 successive application externally of cone upon cone of new 
 ligneous matter ; so that if we make a transverse section 
 near the base of the trunk, we intersect a much greater 
 number of layers than nearer to the summit. When branches 
 occasionally shoot out from the trunk, they first pierce the 
 bark, and then, after growing to a certain size, if they 
 chance to be broken off, they may become inclosed in the 
 body of the tree, as it augments in size, forming knots in 
 the wood, which are themselves composed of layers of ligneous 
 matter, cone within cone. 
 
 In like manner, a volcanic mountain consists, as we have 
 seen, of a succession of conical masses enveloping others, 
 while lateral cones, having a similar internal structure, often 
 project in the first instance, like branches from the surface 
 of the main cone, and then becoming buried again, are hidden 
 like the knots of a tree. . 
 
 We can asoertain the age of an oak or pine by counting 
 the number of concentric rings of annual growth seen in a 
 transverse section near the base, so that we may know the 
 date at which the seedling began to vegetate. The Baobab- 
 tree of Senegal (Adansonia digitatd) is supposed to exceed 
 almost any other in longevity. Adanson inferred that one 
 which he measured, and found to be thirty feet in diameter, 
 had attained the age of 5,150 years. Having made an 
 incision to a certain depth, he first counted 300 rings 
 
CH. XXVI.] ITS GEEAT ANTIQUITY. 45 
 
 of annual growth, and observed what thickness the tree 
 had gained in that period. The average rate of growth of 
 younger trees, of the same species, was then ascertained, and 
 the calculation made according to a supposed mean rate of 
 increase. De Candolle considers it not improbable that the 
 celebrated Taxodium of Chapultepec, in Mexico (Cupressus 
 disticha Linn.), which is 117 feet in circumference, may be 
 more aged. 
 
 It is, however, impossible, until more data are collected 
 respecting the average intensity of the volcanic action, to 
 make anything like an approximation to the age of a cone 
 like Etna ; because, in this case, each successive envelope of 
 lava and scorise is not of simultaneous growth round the 
 mountain, like the layers of wood round a tree, and therefore 
 affords us no corresponding and definite measure of time. 
 Each conical envelope is made up of a great number of dis- 
 tinct lava currents and showers of sand and scoriae differing 
 in width and depth, and also the results of intermittent 
 action exceedingly variable as to intensity and frequency of 
 recurrence. Yet we cannot fail to form the most exalted 
 conception of the antiquity of this mountain, when we con- 
 sider that its base is about 90 miles in circumference ; so 
 that it would require 90 flows of lava, each a mile in 
 breadth at their termination, to raise the present foot of the 
 volcano as much as the average height of one lava current. 
 
 The injection of several thousand dikes into the mass of 
 matter previously accumulated, is more comparable, as M. E. 
 de Beaumont has hinted, to the endogenous growth of a tree 
 implying the stretching outwards and perhaps upwards also 
 of the mountain. But observations within the historical era 
 are too imperfect to enable us to decide whether the moun- 
 tain has gained or lost in altitude at those periods when new 
 fissures have been formed and filled. 
 
 Of the 80 most conspicuous minor cones which adorn the 
 flanks of Etna, only one of the largest, Monti Rossi, has been 
 produced within the times of authentic history. Even this 
 hill, thrown up in the year 1669, although 450 feet in height, 
 only ranks as a cone of second magnitude. Monte Minardo, 
 near Bronte, rises, even now, to the height of 750 feet, 
 
46 ETNA. [Cn. XXVI. 
 
 although, its original base has been elevated by more modern 
 lavas and ejections. It must also be remembered, that of the 
 small number of lava streams which are poured forth in a 
 century, one only is estimated to issue from the summit of 
 Etna for every two that proceed from the sides. Nor do all 
 the lateral eruptions give rise to such hills as would be 
 reckoned amongst the 200 lateral cones before alluded to, 
 p. 2, as laid down in Waltershausen's map. Some of them 
 produce merely insignificant monticules, which are soon after 
 overwhelmed by showers of ashes proceeding from higher 
 vents. 
 
 How many years, then, must we not suppose to have been 
 expended in the formation of all the minor cones ? If we 
 could strip off from Etna the whole of those now visible, 
 together with the lavas and scoriae that have been poured out 
 from them, and from the highest crater, during the period 
 of their growth, the diminution of the entire mass would be 
 extremely slight : Etna might lose, perhaps, several miles in 
 diameter at its base, but the aspect of the woody region 
 would not be essentially changed, because other minor cones, 
 now concealed, would be recalled as it were into existence by 
 the removal of the lava and ejected matter under which they 
 now lie buried. As to the height of the mountain during 
 the early stages of the phase of lateral eruptions, it may have 
 been much greater before its summit was truncated than it 
 is now, even if we make allowance for a slight accession of 
 height due to the gradual upheaval of the whole mass above 
 the level of the sea, as testified by the raised beaches on the 
 coast before described. 
 
 To attempt to estimate the number of centuries which have 
 elapsed since the first submarine eruptions began would be 
 idle, because there may have been periods of tranquillity 
 such as that in which the ancient valleys were excavated, 
 enduring perhaps for tens of thousands of years, and then 
 followed by paroxysmal outbursts like that to which the 
 Yal del Bove may have owed its origin. 
 
 No general deluge can have occurred in the forest zone of 
 Etna since the lateral cones were thrown up. For few, if 
 any, of these heaps of loose scoriae could fail to have been 
 
CH. XXVI.] ITS GREAT ANTIQUITY. 47 
 
 swept away by a great flood, and all of them would have ex- 
 hibited some signs of its denuding action. To some, perhaps, 
 it may appear that hills of such incoherent materials cannot 
 be of very great antiquity, because the mere action of the 
 atmosphere must, in the course of several thousand years, 
 have obliterated their original forms. But there is no 
 weight in this objection ; for although the steep slopes of 
 Monti Eossi, being still bare and composed in great part of 
 light scoriae and fine volcanic sand, have been acted upon both 
 by wind and rain within the memory of persons now living, 
 yet the older hills have been protected from waste ever since 
 they have been covered with trees and herbage. Even before 
 dense vegetation has been established, such is the porosity 
 of their component materials, that almost all the rain which 
 falls upon them is instantly absorbed ; and for the same 
 reason that the rivers on Etna have a subterranean course, 
 there are no rills descending the sides of the minor cones. 
 
 In conclusion, I may remind the reader that, however vast 
 may be the lapse of ages which we require for the growth of 
 a mountain like Etna, there has been ample time for its pas- 
 sage through every phase of its development. Its foundations 
 were laid in the sea, in the Newer Pliocene period that sea 
 in which the shells of Aci Castello and Trezza flourished. 
 We have seen at p. 6 that the events of the Glacial Period, 
 though they may have occupied several hundred thousand 
 years, do not reach back to an era when the assemblage of 
 marine testacea diifered as much as those of Aci Castello 
 and Trezza differ from the fauna now characterising the 
 neighbouring parts of the Mediterranean. 
 
CHAPTER XXVII. 
 
 VOLCANIC ERUPTIONS concluded. 
 
 VOLCANIC ERUPTION IN ICELAND IN 1783 NEW ISLAND THROWN UP LAVA 
 
 CURRENTS OF SKAPTAR JOKUL, IN SAME TEAR THEIR IMMENSE VOLUME 
 
 ERUPTION OF JORULLO IN MEXICO -HUMBOLDT's THEORY OF THE CONVEXITY 
 
 OF THE PLAIN OF MALPAIS ERUPTION OF GALONGOON IN JAVA SUBMARINE 
 
 VOLCANOS GRAHAM ISLAND, FORMED IN 1831 VOLCANIC ARCHIPELAGOS 
 
 SUBMARINE ERUPTIONS IN MID-ATLANTIC THE CANARIES CONES THROWN UP 
 
 IN LANCEROTE, 1730-36 SANTORIN AND ITS VOLCANIC ERUPTIONS BARKEN 
 
 ISLAND IN THE BAY OF BENGAL MUD VOLCANOS MINERAL COMPOSITION OF 
 
 VOLCANIC PRODUCTS. 
 
 VOLCANIC ERUPTIONS IN ICELAND. With, the exception of 
 Etna and Vesuvius, the most complete chronological records 
 of a series of eruptions are those of Iceland, for their history 
 reaches as far back as the ninth century of our era; and, 
 from the beginning of the twelfth century, there is clear 
 evidence that, during the whole period, there has never been 
 an interval of more than forty, and very rarely one of twenty 
 years, without either an eruption or a great earthquake. So 
 intense is the energy of the volcanic action in this region, 
 that some eruptions of Hecla have lasted six years without 
 ceasing. Earthquakes have often shaken the whole island 
 at once, causing great changes in the interior, such as the 
 sinking down of hills, the rending of mountains, the desertion 
 by rivers of their channels, and the appearance of new lakes. * 
 New islands have often been thrown up near the coast, some 
 of which still exist; while others have disappeared, either by 
 subsidences or the action of the waves. 
 
 In the interval between eruptions, innumerable hot springs 
 afford vent to the subterranean heat, and solfataras discharge 
 copious streams of inflammable matter. The volcanos in 
 different parts of this island are observed, like those of the 
 
 * Von Hoff, vol. ii. p. 393. 
 
CH. XXVII.] ERUPTIONS OF SKAPTAR JOKUL. 49 
 
 Phlegrsean Fields, to be in activity by turns, one vent often 
 serving for a time as a safety-valve to the rest. Many cones 
 are often thrown up in one eruption, and in this case they 
 take a linear direction, running generally from north-east to 
 south-west, from the north-eastern part of the island, where 
 the volcano Krabla lies, to the promontory Beykianas. 
 
 Great eruption of STtaptdr Jokul in 1783. New island thrown 
 up. The convulsions of the year 1783 appear to have been 
 more tremendous than any recorded in the modern annals of 
 Iceland; and the original Danish narrative of the catastrophe, 
 drawn up in great detail, has since been substantiated by 
 several English travellers, particularly in regard to the pro- 
 digious extent of country laid waste, and the volume of lava 
 produced.* About a month previous to the eruption of 
 Skaptar Jokul on the mainland, presently to be mentioned, a 
 submarine volcano burst forth in the sea in lat. 63 25' N., 
 long. 23 44' W., at a distance of 30 miles in a south-west 
 direction from Cape Eeykianas, and ejected so much pumice, 
 that the ocean was covered with that substance to the dis- 
 tance of 150 miles, and ships were considerably impeded in 
 their course. A new island was formed, from which fire, 
 smoke, and pumice were emitted at different points. This 
 island was claimed by his Danish Majesty, who denominated 
 it Nyoe, or the New Island; but before a year had elapsed, 
 the sea resumed its ancient domain, and nothing was left but 
 a reef of rocks from 5 to 30 fathoms under water. 
 
 Earthquakes which had long been felt in Iceland, became 
 violent on June 11, 1783, when Skaptar Joku), distant nearly 
 200 miles from Nyoe, threw out a torrent of lava which 
 flowed down into the Skapta, and completely dried it up. 
 The channel of the river was between high rocks, in many 
 places from 400 to 600 feet in depth, and near 200 in breadth. 
 
 * The first narrative of the eruption and length of the lava currents, by re- 
 was drawn up by Stephenson, then Chief ference to the MS. of Mr. Paulson, who 
 Justice in Iceland, appointed commis- visited the tract in 1794, and examined 
 sioner by the King of Denmark for the lava with attention. (Journal of a 
 estimating the damage done to the Residence in Iceland, &c., p. 229.) Some 
 country, that relief might be afforded to of the principal facts are also corro- 
 the sufferers. Henderson was enabled borated by Sir William Hooker, in his 
 to correct some of the measurements ' Tour in Iceland,' vol. ii. p. 128. 
 given by Stephenson, of the depth, width, 
 VOL. II. E 
 
50 VOLCANIC ERUPTIONS IN ICELAND. [Cn. XXVII. 
 
 Not only did tlie lava fill up this great defile to the brink, 
 but it overflowed the adjacent fields to a considerable extent. 
 The burning flood, on issuing from the confined rocky gorge, 
 was then arrested for some time by a deep lake, which for- 
 merly existed in the course of the river, between Skaptardal 
 and Aa, which it entirely filled. The current then advanced 
 again, and reaching some ancient lava full of subterraneous 
 caverns, some of them apparently filled with water, melted 
 parts of the rock and blew up others, throwing large frag- 
 ments to the height of 150 feet into the air. On June 18, 
 another ejection of liquid lava rushed from the volcano, which 
 flowed down with amazing velocity over the surface of the 
 first stream. By the damming up of the mouths of some of 
 the tributaries of the Skapta, many villages were completely 
 overflowed with water, and thus great destruction of property 
 was caused. The lava, after flowing for several days, was 
 precipitated down a tremendous cataract called Stapafoss, 
 where it filled a profound abyss, which that great waterfall 
 had been hollowing out for ages, and after this, the fiery 
 current again continued its course. 
 
 On August 3, fresh floods of lava still pouring from the 
 volcano, a new branch was sent off in a different direction ; 
 for the channel of the Skapta was now so entirely choked up, 
 and every opening to the west and north was so obstructed, 
 that the melted matter was forced to take a new course, so 
 that it ran in a south-east direction, and discharged itself 
 into the bed of the river Hverfisfliot, where a scene of de- 
 struction scarcely inferior to the former was occasioned. 
 These Icelandic lavas (like the ancient streams which are 
 met with in Auvergne, and other provinces of Central 
 France), are stated by Stephenson to have accumulated to 
 a prodigious depth in narrow rocky gorges ; but when 
 they came to wide alluvial plains, they spread themselves 
 out into broad burning lakes, sometimes from 12 to 15 
 miles wide, and 100 feet deep. When the ' fiery lake' 
 which filled up the lower portion of the valley of the Skapta 
 had been augmented by new supplies, the lava flowed up 
 the course of the river to the foot of the hills from whence 
 the Skapta takes its rise. This affords a parallel case to one 
 
CH. XXVII.] IMMENSE VOLUME OF THE LAVA. 51 
 
 wliicli can be shown to have happened at a remote era in the 
 volcanic region of the Yivarais in France, where lava issued 
 from the cone of Thueyts, and while one branch ran down, 
 another more powerful stream flowed up, the channel of the 
 river Ardeche. 
 
 The sides of the valley of the Skapta present superb ranges 
 of basaltic columns of older lavas, resembling those which 
 are laid open in the valleys descending from Mont Dor in 
 Auvergne, where more modern lava currents, on a scale very 
 inferior in magnitude to those of Iceland, have also usurped 
 the beds of the existing rivers. The eruption of Skaptar 
 Jokul did not entirely cease till the end of two years ; and 
 when Mr. Paulson visited the tract eleven years afterwards 
 in 1794, he found columns of smoke (or vapour) still rising 
 from parts of the lava, and several rents filled with hot 
 water.* 
 
 Although the population of Iceland was very much scattered, 
 and did not exceed 50,000, no less than twenty villages were 
 destroyed, besides those inundated by water; and more than 
 9,000 human beings perished, together with an immense 
 number of cattle, partly by the depredations of the lava, 
 partly by the noxious vapours which impregnated the air, 
 and, in part, by the famine caused by showers of ashes 
 throughout the island, and the desertion of the coasts by the 
 fish. 
 
 Immense volume of the lava. But the extraordinary volume 
 of melted matter produced in this eruption deserves the 
 particular attention of the geologist. Of the two branches, 
 which flowed in nearly opposite directions, the greatest was 
 50, and the lesser 45 miles in length. The extreme breadth 
 which the Skapta branch attained in the low countries 
 was from 12 to 15 miles, that of the other about 7. The 
 ordinary height of both currents was 100 feet, but in narrow 
 defiles it sometimes amounted to 600. Professor Bischoff 
 has calculated, that the mass of lava brought up from 
 the subterranean regions by this single eruption f surpassed 
 in magnitude the bulk of Mont Blanc. 'f But a more 
 
 * Henderson's Journal, &c., p. 228. 
 
 t Jameson's Phil. Journ. vol. xxvi. p. 291. 
 
 E 2 
 
52 ANCIENT AND MODERN LAVAS COMPARED. [Cn. XXVII. 
 
 distinct idea will be formed of the dimensions of the two 
 streams, if we consider how striking a feature they would 
 now form in the geology of England, had they been poured 
 out on the bottom of the sea after the deposition, and before 
 the elevation of our secondary and tertiary rocks. The 
 same causes which have excavated valleys through parts of 
 our marine strata, once continuous, might have acted with 
 equal force on the igneous rocks, leaving, at the same time, 
 a sufficient portion undestroyed to enable us to discover 
 their former extent. Let us, then, imagine the termination 
 of the Skapta branch of lava to rest on the escarpment of the 
 inferior and middle oolite, where it commands the vale of 
 Gloucester. The great platform might be 100 feet thick, 
 and from 10 to 15 miles broad, exceeding any which can be 
 found in Central France. We may also suppose great tabular 
 masses to occur at intervals, capping the summit of the Cots- 
 wold Hills between Gloucester and Oxford, by Northleach, 
 Burford, and other towns. The wide valley of the Oxford clay 
 would then occasion an interruption for many miles ; but the 
 same rocks might recur on the summit of Cumnor and Shot- 
 over Hills, and all the other oolitic eminences of that district. 
 On the chalk of Berkshire, other tabular masses, 6 or 7 miles 
 wide, might again be found ; and, lastly, crowning the 
 highest sands of Highgate and Hampstead, we might behold 
 some remnants of the current 500 or 600 feet in thickness, 
 causing those hills to rival, or even to surpass, in height, 
 Salisbury Craigs and Arthur's Seat. 
 
 The distance between the extreme points here indicated 
 would not exceed 90 miles in a direct line ; and we might 
 then add, at the distance of nearly 200 miles from London, 
 along the coast of Dorsetshire and Devonshire, for example, 
 a great mass of igneous rocks, to represent the submarine 
 reef of the island of Nyoe. An eminent French writer 
 declared in 1829 that all geological phenomena took place 
 in ancient times on a scale of magnitude a hundredfold 
 greater than those which are witnessed in our days, but it 
 would be difficult to point out a mass of igneous rock of 
 ancient date (distinctly referable to a single eruption) which 
 
CH. XXVII.] ERUPTION OF JORULLO, A.D. 1759. 53 
 
 would even rival in volume the matter poured out from 
 Skaptar Jokul in 1783. 
 
 Eruption of Jorullo in 1759. As another example of the 
 stupendous scale of modern volcanic eruptions, I may mention 
 that of Jorullo in Mexico, in 1759. The great region to which 
 this mountain belongs has already been described. The plain 
 of Malpais forms part of an elevated platform, between 2,000 
 and 3,000 feet above the level of the sea, and is bounded by 
 hills composed of basalt, trachyte, and volcanic tuff, clearly 
 indicating that the country had previously, though probably 
 at a remote period, been the theatre of igneous action. From 
 the era of the discovery of the New World to the middle of 
 the last century, the district had remained undisturbed, and 
 the space, now the site of the volcano, which is 36 leagues 
 distant from the nearest sea, was occupied by fertile fields of 
 sugar-cane and indigo, and watered by the two brooks 
 Cuitimba and San Pedro. In the month of June, 1759, 
 hollow sounds of an alarming nature were heard, and 
 earthquakes succeeded each other for two months, until, at 
 the end of September, flames issued from the ground, and 
 fragments of burning rocks were thrown to prodigious 
 heights. Six volcanic cones, composed of scoriae and frag- 
 mentary lava, were formed on the line of a chasm which ran 
 in the direction from OTTE. to SSW. The least of these 
 cones was 300 feet in height ; and Jorullo, the central 
 volcano, was elevated 1,600 feet above the level of the plain. 
 It sent forth great streams of basaltic lava, containing 
 included fragments of granitic rocks, and its ejections did not 
 cease till the month of February, 1760.* 
 
 Humboldt visited the country more than forty years after 
 this occurrence, and was informed by the Indians, that when 
 they returned, long after the catastrophe, to the plain, they 
 found the ground uninhabitable from the excessive heat. 
 When he himself visited the place, there appeared, around the 
 base of the cones, and spreading from them, as from a centre, 
 over an extent of four square miles, a mass of matter of a 
 convex form, about 550 feet high at its junction with the cones, 
 
 * Daubeny on Volcanos, p. 337. 
 
54 CONVEXITY OF THE PLAIN OF MALFAIS. [Cn. XXVII. 
 
 and gradually sloping from them in all directions towards the 
 plain. This mass was still in a heated state, the tempe- 
 rature in the fissures being on the decrease from year to year, 
 but in 1780 it was still sufficient to light a cigar at the depth 
 of a few inches. On this slightly convex protuberance, the 
 slope of which must form an angle of about 6 with the 
 horizon, were thousands of flattish conical mounds, from 6 
 to 9 feet high, which, as well as large fissures traversing 
 the plain, acted as fumeroles, giving out clouds of sulphurous 
 acid and hot aqueous vapour. The two small rivers before 
 mentioned disappeared during the eruption, losing themselves 
 
 Fig. 89. 
 
 a. Summit of JoruHo. 6, c. Inclined plane sloping at an angle of 6 from the base of the cones. 
 
 below the eastern extremity of the plain, and reappearing as 
 hot springs at its western limit. 
 
 Cause of the convexity of the plain of Malpais. Humboldt 
 attributed the convexity of the plain to inflation from below ; 
 supposing the ground, for four square miles in extent, to 
 have risen up in the shape of a bladder to the elevation of 
 550 feet above the plain in the highest part. But Mr. Scrope 
 has suggested that the phenomena may be accounted for far 
 more naturally, by supposing that lava flowing simultaneously 
 from the different orifices, and principally from Jorullo, 
 united into a sort of pool or lake. As they were poured forth 
 on a surface previously flat, they would, if their liquidity was 
 not very great, remain thickest and deepest near their source, 
 and diminish in bulk from thence towards the limits of the 
 space which they covered. Fresh supplies were probably 
 emitted successively during the course of an eruption which 
 lasted more than half a year ; and some of these, resting on 
 those first emitted, might only spread to a small distance 
 from the foot of the cone, where they would necessarily 
 accumulate to a great height. The average slope of the 
 great dome-shaped volcanos of the Sandwich Islands, formed 
 almost exclusively of lava, with scarce any scoriae, is between 
 6 30' and 7 46', so that the inclination of the convex mass 
 around Jorullo, if we adopt Mr. Scrope's explanation (see 
 
CH. XXVII.] CONVEXITY OF THE PLAIN OF MALPAIS. 55 
 
 fig. 89), is quite in accordance with the known laws which 
 govern the now of lava. 
 
 The showers, also, of loose and pulverulent matter from the 
 six craters, and principally from Jorullo, would be composed 
 of heavier and more bulky particles near the cones, and 
 would raise the ground at their base, where, mixing with 
 rain, they might have given rise to the stratum of black clay, 
 which is described as covering the lava. The small conical 
 mounds (called ' hornitos,' or little ovens) may resemble those 
 five or six small hillocks which existed in 1823 on the 
 Yesuvian lava, and sent forth columns of vapour, having been 
 produced by the disengagement of elastic fluids heaving up 
 small dome-shaped masses of lava. The fissures mentioned 
 by Humboldt as of frequent occurrence, are such as might 
 naturally accompany the consolidation of a thick bed of lava, 
 contracting as it congeals ; and the disappearance of rivers 
 is the usual result of the occupation of the lower part of a 
 valley or plain by lava, of which there are many beautiful 
 examples in the old lava currents of Auvergne. The heat of 
 the * hornitos ' is stated to have diminished from the first ; 
 and Mr. Bullock, who visited the spot many years after 
 Humboldt, found the temperature of the hot spring very low 
 a fact which seems clearly to indicate the gradual conge- 
 lation of a subjacent bed of lava, which from its immense 
 thickness may have been enabled to retain its heat for half 
 a century. The reader may be reminded, that when we thus 
 suppose the lava near the volcano to have been, together 
 with the ejected ashes, more than 500 feet in depth, we 
 merely assign a thickness which the current of Skaptar Jokul 
 attained in some places in 1783. 
 
 Hollow sound of the plain when struck. Another argument 
 adduced in support of the theory of inflation from below, was, 
 the hollow sound made by the steps of a horse upon the 
 plain ; which, however, proves nothing more than that the 
 materials of which the convex mass is composed are light and 
 porous. The sound called ' rimbombo ' by the Italians is 
 very commonly returned by made ground when struck sharply ; 
 and has been observed not only on the sides of Vesuvius and 
 other volcanic cones where there is a cavity below, but in 
 
56 VOLCANIC ERUPTIONS IN JAVA. [Cn. XXVII. 
 
 such regions as the Campagna di Roma, composed in a 
 great measure of tuff and porous volcanic rocks. The rever- 
 beration, however, may perhaps be assisted by grottos and 
 caverns, for these may be as numerous in the lavas of Jorullo 
 as in many of those of Etna ; but their existence would lend 
 no countenance to the hypothesis of a great arched cavity, 
 four square miles in extent, and in the centre 550 feet 
 high.* 
 
 No recent eruptions of Jorullo. In a former edition I stated 
 that I had been informed by Captain Vetch, that in 1819 a 
 tower at Guadalaxara was thrown down by an earthquake, 
 and that ashes, supposed to have come from Jorullo, fell at 
 the same time at Guanaxuato, a town situated 140 English 
 miles from the volcano. But Mr. Burkhardt, a German 
 director of mines, who examined Jorullo in 1827, ascertained 
 that there had been no eruption there since Humboldt's visit 
 in 1803. He went to the bottom of the crater, and observed 
 a slight evolution of sulphurous acid vapours, but the 
 ' hornitos ' had entirely ceased to send forth steam. During 
 the twenty-four years intervening between his visit and that 
 of Humboldt, vegetation had made great progress on the 
 flanks of the new hills, the rich soil of the surrounding 
 country was once more covered with luxuriant crops of 
 sugar-cane and indigo, and there was an abundant growth of 
 natural underwood on all the uncultivated tracts, f 
 
 Galongoon, Java, 1822. The mountain of Galongoon (or 
 Galung Gung) was in 1822 covered by a dense forest, and 
 situated in a fruitful and thickly-peopled part of Java. 
 There was a circular hollow at its summit, but no tradition 
 existed of any former eruption. In July, 1822, the waters of 
 the river Kunir, one of those which flowed from its flanks, 
 became for a time hot and turbid. On October 8 following, 
 a loud explosion was heard, the earth shook, and immense 
 columns of hot water and boiling mud, mixed with burning 
 brimstone, ashes, and lapilli, of the size of nuts, were projected 
 from the mountain like a water-spout, with such prodigious 
 violence that large quantities fell beyond the river Tandoi, 
 
 * See Scrope on Volcanos, p. 267. 
 
 f Leonhard and Bronn's Neues Jahrbuch, 1835, p. 36. 
 
CH. XXVII.] ERUPTIONS OF GALONGOON, JAVA, IN 1822. 57 
 
 which, is 40 miles distant. Every valley within the range of this 
 eruption became filled with a burning torrent, and the rivers, 
 swollen with hot water and mud, overflowed their banks, and 
 carried away great numbers of the people, who were en- 
 deavouring to escape, and the bodies of cattle, wild beasts, 
 and birds. A space of 24 miles between the mountain and 
 the river Tandoi was covered to such a depth with bluish mud 
 that people were buried in their houses, and not a trace of 
 the numerous villages and plantations throughout that extent 
 was visible. Within this space the bodies of those who 
 perished were buried in mud and concealed, but near the 
 limits of the volcanic action they were exposed, and strewed 
 over the ground in great numbers, partly boiled and partly 
 burnt. 
 
 It was remarked, that the boiling mud and cinders were 
 projected with such violence from the mountain, that while 
 many remote villages were utterly destroyed and buried, 
 others much nearer the volcano were scarcely injured. 
 
 The first eruption lasted nearly five hours, and on the 
 following days the rain fell in torrents, and the rivers, densely 
 charged with mud, deluged the country far and wide. At 
 the end of four days (October 12th), a second eruption 
 occurred more violent than the first, in which hot water and 
 mud were again vomited, and great blocks of basalt were 
 thrown to the distance of 7 miles from the volcano. 
 There was at the same time a violent earthquake, and in 
 one account it is stated that the face of the mountain was 
 utterly changed, its summit broken down, and one side, 
 which had been covered with trees, became an enormous 
 gulf in the form of a semicircle. This cavity was about 
 midway between the summit and the plain, and surrounded 
 by steep rocks, said to be newly heaped up during the erup- 
 tion. New hills and valleys are said to have been formed, 
 and the rivers Banjarang and Wulan changed their course, 
 and in one night (October 12th) 2,000 persons were killed. 
 
 The first intimation which the inhabitants of Bandong 
 received of this calamity on October 8th, was the news that 
 the river Wulna was bearing down into the sea the dead 
 bodies of men, and the carcasses of stags, rhinoceroses, tigers, 
 
58 SUBMARINE VOLCANOS. [Cn. XXVII. 
 
 and other animals. The Dutch painter Payen determined 
 to travel from thence to the volcano, and he found that the 
 quantity of the ashes diminished as he approached the base 
 of the mountain. He alludes to the altered form of the 
 mountain after the 12th, but does not describe the new semi- 
 circular gulf on its side. 
 
 The official accounts state that 114 villages were destroyed, 
 and above 4,000 persons killed.* 
 
 Submarine volcanos. Although we have every reason to 
 believe that volcanic eruptions as well as earthquakes are 
 common in the bed of the sea, it was not to be expected that 
 many opportunities would occur to scientific observers of 
 witnessing the phenomena. The crews of vessels have some- 
 times reported that they have seen in different places sul- 
 phurous smoke, flame, jets of water, and steam, rising up 
 from the sea, or they have observed the waters greatly dis- 
 coloured, and in a state of violent agitation as if boiling. 
 New shoals have also been encountered, or a reef of rocks 
 just emerging above the surface, where previously there was 
 always supposed to have been deep water. On some few 
 occasions the gradual formation of an island by submarine 
 eruption has been observed, as that of Sabrina, in the year 
 1811, off St. Michael's in the Azores. The throwing up of 
 ashes in that case, and the formation of a cone about 300 
 feet in height, with a crater in the centre, closely resembled 
 the phenomena usually accompanying a volcanic eruption on 
 land. Sabrina was soon washed away by the waves. Pre- 
 vious eruptions in the same part of the sea were recorded 
 to have happened in 1691 and 1720. The rise of Nyoe, 
 also, a small island off the coast of Iceland, in 1783, has 
 already been alluded to ; and another volcanic isle was pro- 
 duced by an eruption near Eeikiavig, on the same coast, in 
 June, 1830.f 
 
 Graham Island,^ 1831. We have still more recent and 
 
 * Van der Boon Mesch, de Incendiis f Journ. de Geol. tome i. 
 
 Montiura Javse, &c. Lngd. Bat. 1826; j In a former edition, I selected the 
 
 and Official Keport of the President, name of Sciacca out of seven which had 
 
 Baron Van der Capellen ; also, Von been proposed ; but the Royal and 
 
 Buch, lies Canar., p. 424. Geographical Societies have nowadopted 
 
CH. XXVII.] 
 
 GRAHAM ISLAND. 
 
 50 
 
 minute information respecting the appearance, in 1831, of a 
 new volcanic island in the Mediterranean, between the 
 SW. coast of Sicily and that projecting part of the African 
 coast where ancient Carthage stood. The site of the island 
 was not any part of the great shoal, or bank, called ' Nerita,' 
 as was first asserted, but a spot where Captain W. H. Smyth 
 had found, in his survey a few years before, a depth of more 
 than 100 fathoms' water.* 
 
 The position of the island (lat. 37 I' 30" K, long. 12 42' 
 15" E.) was about 30 miles SW. of Sciacca, in Sicily, and 
 33 miles NE. of the Island of Pantellaria.f On June 
 28, about a fortnight before the eruption was visible, Sir 
 
 Fig. 90. 
 
 Form of the cliffs of Graham Island, as seen from SSE., distant one mile, 
 7th August, 1831.f 
 
 Pulteney Malcolm, in passing over the spot in his ship, felt 
 the shocks of an earthquake, as if he had struck on a sand- 
 bank ; and the same shocks were felt on the west coast of 
 Sicily, in a direction from SW. to NE. About July 10, 
 John Corrao, the captain of a Sicilian vessel, reported that, 
 as he passed near the place, he saw a column of water like 
 a water-spout 60 feet high, and 800 yards in circumference, 
 rising from the sea, and soon afterwards a dense steam in its 
 place, which ascended to the height of 1,800 feet. The 
 same Corrao, on his return from Girgenti, on July 18, found 
 a small island, 12 feet high with a crater in its centre, ejecting 
 volcanic matter, and immense columns of vapour; the sea 
 
 Graham Island ; a name given by Capt. 
 Senhouse, E.N., the first who succeeded 
 in landing on it. The seven rival 
 names are Nerita, Ferdinanda, Hotham, 
 Graham, Corrao, Sciacca, Julia. As 
 the isle was visible for only about three 
 months, this is an instance of a wanton 
 multiplication of synonyms which has 
 
 scarcely ever been outdone even in the 
 annals of zoology and botany. 
 
 * Phil. Trans. 1832, p. 255. 
 
 f Journ. of Roy. Geograph. Soc. 
 1830-31. 
 
 J Phil. Trans., part ii., 1832, reduced 
 from drawings by Captain Wodehouse, 
 K.N. 
 
GO 
 
 GRAHAM ISLAND. 
 
 [Cn. XXVII. 
 
 around being covered with floating cinders and dead fish. 
 The scoriae were of a chocolate colour, and the water which 
 boiled in the circular basin was of a dingy red. The eruption 
 
 Fig. 91. 
 
 View of the interior of Graham Island, 29th Sept. 1831. 
 
 continued with great violence to the end of the same month ; 
 at which time the island was visited by several persons, and 
 among others by Capt. Swinburne, K. N., and M. Hoffmann, 
 
 Fig. 92. 
 
 Graham Island, 29th Sept. 1831.* 
 
 the Prussian geologist. It was then from 50 to 90 feet in 
 height, and j of a mile in circumference. By August 4 it 
 became, according to some accounts, above 200 feet high, 
 
 * In the annexed sketch (fig. 92), 
 drawn by M. Joinville, who accompanied 
 M. C. Prevost, the beds seem to slope 
 towards the centre of the crater ; but I 
 
 am informed by M. Prevost that these 
 lines were not intended by the artist to 
 represent the dip of the beds. 
 
CH. XXVII.] GRAHAM ISLAND IN 1831. 61 
 
 and 3 miles in circumference ; after which it began to di- 
 minish in size by the action of the waves, and was only 2 
 miles round on August 25 ; and on September 3, when it 
 was carefully examined by Captain Wodehouse, only J- of a 
 mile in circumference ; its greatest height being then 107 feet. 
 At this time the crater was about 780 feet in circumference. 
 On September 29, when it was visited by Moiis. C. Prevost, 
 its circumference was reduced to about 700 yards. It was 
 composed entirely of incoherent ejected matter, scoriae, 
 pumice, and lapilli, forming regular strata, some of which 
 are described as having been parallel to the steep inward 
 slope of the crater, while the rest were inclined outwards, 
 like those of Vesuvius.* When the arrangement of the 
 ejected materials has been determined by their falling con- 
 tinually on two steep slopes, that of the external cone and 
 that of the crater, which is always a hollow inverted cone, a 
 
 Fig. 93. 
 
 transverse section would probably resemble that given in the 
 annexed figure (93). But when I visited Vesuvius, in 1828, 
 I saw no beds of scorise inclined towards the axis of the cone. 
 (See fig. 67, Yol. I. p. 631.) Such may have once existed ; but 
 the explosions or subsidences, or whatever causes produced 
 the great crater of 1822, had possibly destroyed them. 
 
 Few of the pieces of stone thrown out from Graham Island 
 exceeded a foot in diameter. Some fragments of dolornitic 
 limestone were intermixed; but these were the only non- 
 volcanic substances. During the month of August, there 
 occurred on the S. W. side of the new island a violent ebul- 
 lition and agitation of the sea, accompanied by the constant 
 ascension of a column of dense white steam, indicating the 
 existence of a second vent at no great depth from the surface. 
 Towards the close of October, no vestige of the crater re- 
 mained, and the island was nearly levelled with the surface 
 of the ocean, with the exception, at one point, of a small 
 monticule of sand and scorise. It was reported that, at the 
 
 * See Memoir by M.C. Prevost, Ann. des Sci. Nat. torn. xxiv. 
 
62 GRAHAM ISLAND. [Cn. XXVII. 
 
 commencement of the year following (1832), there was a 
 depth of 150 feet where the island had been: but this 
 account was quite erroneous ; for in the early part of that 
 year Captain Swinburne found a shoal and discoloured water 
 there, and towards the end of 1833 a dangerous reef existed 
 of an oval figure, about |- of a mile in extent. In the centre 
 was a black rock, of the diameter of about 26 fathoms, from 
 9 to 11 feet under water; and round this rock are banks of 
 black volcanic stones and loose sand. At the distance of 
 60 fathoms from this central mass, the depth increased 
 rapidly. There was also a second shoal at the distance 
 of 450 feet SW. of the great reef, with 15 feet water over 
 it, also composed of rock, surrounded by deep sea. We can 
 scarcely doubt that the rock in the middle of the larger reef 
 is solid lava, which rose up in the principal crater, and that 
 the second shoal marks the site of the submarine eruption 
 observed in August, 1831, to the SW. of the island. 
 
 From the whole of the facts above detailed, it appears 
 that a hill 800 feet or more in height was formed by a 
 submarine volcanic vent, of which the upper part (only about 
 200 feet high) emerged above the waters, so as to form 
 an island. This cone must have been equal in size to 
 one of the largest of the lateral volcanos on the flanks of 
 Etna, and about half the height of the mountain Jorullo in 
 Mexico, which was formed in the course of nine months, in 
 1759. In the centre of the new volcano a large cavity was 
 kept open by gaseous discharges, which threw out scorise ; 
 and fluid lava probably rose up in this cavity. It is not 
 uncommon for small subsidiary craters to open near the 
 summit of a cone, and one of these may have been formed in 
 the case of Graham Island ; a vent perhaps, connected with 
 the main channel of discharge which gave passage in that 
 direction to elastic fluids, scorise, and melted lava. It does 
 not appear that, either from this duct, or from the principal 
 vent, there was any overflowing of lava; but melted rock 
 may have flowed from the flanks or base of the cone (a common 
 occurrence on land), and may have spread in a broad sheet 
 over the bottom of the sea. 
 
 The dotted lines in the annexed figure are an imaginary 
 
CH. XXVII.] 
 
 GEAHAM ISLAND. 
 
 63 
 
 restoration of the upper part of the cone, now removed by 
 the waves : the strong lines represent the part of the volcano 
 which is still under water : in the centre is a great column, 
 or dike, of solid lava, 200 feet in diameter, supposed 
 to fill the space by which the gaseous fluids rose ; and on 
 each side of the dike is a stratified mass of scoriae and frag- 
 mentary lava. The solid nucleus of the reef, where the 
 black rock is now found, withstands the movements of the 
 sea ; while the surrounding loose tuffs are cut away to a 
 somewhat lower level. In this manner the lava, which was 
 the lowest part of the island, or, to speak more correctly, 
 which scarcely ever rose above the level of the sea when the 
 island existed, has now become the highest point in the reef. 
 No appearances observed, either during the eruption or 
 since the island disappeared, give the least support to the 
 
 Fig. 94. 
 
 Supposed section of Graham Island. (C. Maclaren.*) 
 
 opinion promulgated by some writers, that part of the 
 ancient bed of the sea had been lifted up bodily. 
 
 The solid products, says Dr. John Davy, whether they 
 consisted of sand, light cinders, or vesicular lava, differed 
 more in form than in composition. The lava contained 
 augite; and the specific gravity was 2*07 and 2*70. When 
 the light spongy cinder, which floated 011 the sea, was reduced 
 to fine powder by trituration, and the greater part of the 
 entangled air got rid of, it was found to be of the specific 
 gravity 2*64 ; and that of some of the sand which fell in the 
 eruption was 2*75;f so that the materials equalled ordinary 
 granites in weight and solidity. The only gas evolved in any 
 considerable quantity was carbonic acid.J 
 
 Submarine eruptions in mid-Atlantic. In the Nautical 
 
 * Geol. of Fife and the Lothians, 
 p. 41. Edin. 1839. 
 
 f Phil. Trans. 1832, p. 243. 
 { Ibid. p. 249. 
 
64 ERUPTION IN THE CANARY ISLANDS. [Cir. XXVII. 
 
 Magazine for 1835, p. 642, and for 1838, p. 361, and in the 
 Comptes Rendus, April, 1838, accounts are given of a series 
 of volcanic phenomena, earthquakes, troubled water, floating 
 scorise and columns of smoke, which have been observed at 
 intervals since the middle of the last century, in a space of 
 open sea between longitudes 20 and 22 west, about half a 
 degree south of the equator. These facts, says Mr. Darwin, 
 seem to show, that an island or an archipelago is in process 
 of formation in the middle of the Atlantic : a line joining 
 St. Helena and Ascension would, if prolonged, intersect this 
 slowly nascent focus of volcanic action.* Should land be 
 eventually formed here, it will not be the first that has been 
 produced by igneous action in this ocean since it was 
 inhabited by the existing species of testacea. At Porto Praya 
 in St. Jago, one of the Azores, a horizontal, calcareous 
 stratum occurs, containing shells of recent marine species, 
 covered by a great sheet of basalt 80 feet thick. f It 
 would be difficult to estimate too highly the commercial and 
 political importance which a group of islands might acquire, 
 if in the next two or three thousand years they should rise in 
 mid-ocean between St. Helena and Ascension. 
 
 Eruption in Lancerote, 1730 to 1736. An eruption hap- 
 pened in Lancerote, one of the Canary Islands, between the 
 years 1730 and 1736, of which a detailed description was 
 published by Yon Buch, who visited that island in 1815, and 
 compared the accounts transmitted to us of the event, with 
 the present state and geological appearances of the country. 
 During this outbreak, which lasted for five successive years, 
 the flourishing town of St. Catalina and several other places 
 were buried under lava and scorise 400 feet in thickness. 
 Thirty cones were thrown up arranged in one line running 
 nearly east and west and extending for a length of two 
 geographical miles. The most elevated of these hills reached 
 a height of about 600 feet above its base. The subterranean 
 cleft from which elastic fluids escaped seems to have opened 
 or widened at a succession of new points when the first 
 apertures had become obstructed by solid lava or ejected 
 
 * Darvrin's Volcanic Islands, p. 92. f Ibid. p. 6. 
 
CH. XXVII.] SANTORIN. 65 
 
 matter. From one of the fissures which was still open in 
 1815 Yon Buch found hot vapours issuing which raised the 
 thermometer to 145 Fahr., and was probably at the boiling 
 point lower down. The exhalations seemed to consist of 
 aqueous vapour ; yet they could not be pure steam, for the 
 crevices were encrusted on either side by silicious sinter (an 
 opal -like hydrate of silica of a white colour), which extended 
 almost to the middle. This important fact attests the length 
 of time during which chemical processes continue after 
 eruptions, and shows how open fissures may be filled up by 
 mineral matter, sublimed from volcanic exhalations. 
 
 The quantity of dead fish which were strewed over the banks 
 and shores of the island or floated on the waters on more than 
 one occasion during this series of eruptions, some of them 
 of species which had never before been observed, is said to 
 have been indescribably great, especially where streams of 
 lava entered the sea. This fact is one of geological interest, 
 since many of the fossil fishes of ancient date, those of Monte 
 Bolca for example, are preserved in volcanic tuff or in marls 
 associated with contemporaneous igneous rocks. In August 
 1824 another eruption happened in Lanzerote near the port 
 of Eescif, forming a cone and crater from which Mr. Hartung 
 found hot vapours escaping during his visit in 1850.* 
 
 SANTORIN. 
 
 The Gulf of Santorin, in the Grecian Archipelago, has 
 been for 2,000 years a scene of active volcanic operations. 
 The largest of the three outer islands of the groups (to which 
 the general name of Santorin is given) is called Thera (or 
 sometimes Santorin), and forms more than two-thirds of the 
 circuit of the gulf. (See Map, fig. 95, p. 66.) The length 
 of the exterior coast-line of this and the other two islands 
 named Therasia and Aspronisi, taken together, amounts to 
 about 30 miles, and that of the inner coast-line of the 
 same islands to about 18 miles. In the middle of the 
 gulf are three other islands, called the Little, the New, and 
 the Old ' Kaimenis,' or ' Burnt Islands.' The accompanying 
 
 * G. Hartung, Lanzerote und Fuertaventura. 1856. 
 VOL. II. F 
 
6G 
 
 SANTORIN. 
 Fig. 95. 
 
 [Cn. XXVII. 
 
 Map of Santorin in the Grecian Archipelago, from a Survey in 1848, by 
 
 Captain Graves, R.N. 
 The soundings are given in fathoms. 
 
 A. Shoal formed by submarine volcanic 
 eruption in 1650. 
 
 B. Northern entrance. 
 
 C. Mansell's Eock. 
 
 D. Mount St. Elias, 1,887 feet high. 
 
 Sea 
 
 Aspronist 
 
 Fig. 96. 
 The ttiree Kaimenis 
 
 Section of Santorin, in a NE. and SW. direction, from Thera through the 
 Kaimenis to Aspronisi. 
 
 a. Old Kaimeni. d, <*'. Great covering of white tufaceous 
 
 b. New Kaimeni. agglomerate or of ejected matter containing 
 
 c. Little Kaimeni. fragments of brown trachyte. 
 
CH. XXVII.] SANTOEIX. 67 
 
 map has been reduced from an Admiralty survey executed, in 
 1848 by the late Captain Graves, E. 1ST. 
 
 Pliny informs us that the year 186, B.C., gave birth to the 
 Old Kaimeni, also called Hiera, or the ' Sacred Isle ; ' and in 
 the year 19 of our era ' Thia ' (the Divine) made its appearance 
 above water, and was soon joined by subsequent eruptions to 
 the older island, from which it was only 250 paces distant. 
 The Old Kaimeni also increased successively in size in 726 
 and in 1427. A century and a half later, in 1573, another 
 eruption produced the cone and crater called Micra-Kainieni, 
 or f the Small Burnt Island.' The next great event which 
 we find recorded occurred in 1650, when a submarine out- 
 break violently agitated the sea, at a point 3^ miles to the 
 NE. of Thera, and which gave rise to a shoal (see A in 
 the Map) carefully examined during the survey of 1848 by 
 Captain Graves, and found to have 10 fathoms water over it, 
 the sea deepening around it in all directions. This eruption 
 lasted three months, covering the sea with floating pumice. 
 At the same time an earthquake destroyed many houses in 
 Thera, while the sea broke upon the coast, overthrew two 
 churches, and exposed to view two villages, one on each side 
 of the mountain of St. Stephen, both of which must have 
 been overwhelmed by showers of volcanic matter during some 
 previous eruptions of unknown date."* The accompanying 
 evolution of sulphur and hydrogen issuing from the sea killed 
 more than 50 persons, and above 1,000 domestic animals. 
 A wave, also, 50 feet high, broke upon the rocks of the Isle 
 of Ma, about 4 leagues distant, and advanced 450 yards 
 into the interior of the Island of Sikino. Lastly, in 1707 and 
 1709, Nea-Kaimeni, or the New Burnt Island, was formed 
 between the two others, Palaia and Micra, the Old and Little 
 Isles. This isle was composed originally of two distinct 
 parts; the first which rose was called the White Island, 
 composed of a mass of pumice, extremely porous. Goree, the 
 Jesuit, who was then in Santorin, says that the rock c cut 
 like bread,' and that, when the inhabitants landed on it, they 
 found a multitude of full-grown fresh oysters adhering 
 
 * Virlet, Bull, de la Soc. Greol. de France, torn. iii. p. lOo. 
 
 F % 
 
68 SANTORIX. [Cii. XXVII. 
 
 to it, which they ate.* This mass was afterwards covered, 
 in great part, by the matter ejected from the crater of 
 a twin-island formed simultaneously, and called Black 
 Island, consisting of brown trachyte. The trachytic lava 
 which rose on this spot appears to have been a long time in 
 an intumescent state, for the New Kaimeni was sometimes 
 lowered on one side while it gained height on the other, and 
 rocks rose up in the sea at different distances from the shore 
 and then disappeared again. The eruption was renewed at 
 intervals during the years 1711 and 1712, and at length a 
 cone was piled up to the height of about 330 feet above the 
 level of the sea, its exterior slope forming an angle of 33 
 with the horizon, and the crater on its summit being 80 
 yards in diameter. In addition to the two points of subaerial 
 eruption on the New and Little Kaimenis, two other cones, 
 indicating the sites of submarine outbursts of unknown date, 
 were discovered under water near the Kaimenis during the 
 late survey. 
 
 In regard to the ' White Island,' which was described and 
 visited by Goree in 1707, we are indebted to Mr. Edward 
 Forbes for having, in 1842, carefully investigated the layer 
 of pumiceous ash of which it is constituted. He obtained 
 from it many shells of marine genera, Pectunculus, Area, 
 Cardita, Trochus, and others, both univalve and bivalve, all 
 of recent Mediterranean species. They were in a fine state 
 of preservation, the bivalves with the epidermis remaining, 
 and valves closed, showing that they had been suddenly 
 destroyed. Mr. Forbes, from his study of the habits of the 
 rnollusca living at different depths in the Mediterranean, was 
 able to decide that such an assemblage of species could not 
 have lived at a less depth than 220 feet, so that a bodily 
 upheaval of the mass to that amount must have taken place 
 in order to bring up this bed of ashes and shells to the level 
 of the sea, and they now rise 5 or 6 feet above that level, f 
 
 We may compare this partial elevation of solid matter to 
 the rise of a hardened crust of scoriae, such as is usually 
 
 * Phil. Trans. No. 332. 
 
 t E. Forbes, Brit. Association, Eeport for 1843, p. 177. 
 
CH. XXVII.] 
 
 GULF OF SANTORIN. 
 
 69 
 
 formed on the surface of lava currents, even while they are 
 in motion, and which, although stony and capable of sup- 
 porting heavy weights, may be upraised without bursting by 
 the intumescence of the melted matter below. The reader 
 may also be reminded of the upheaval of a solid crust of lava 
 witnessed by Abich within the crater of Vesuvius in the 
 year 1834, already mentioned by me. (Vol. I. p. 629.) That 
 the upheaval was merely local is proved by the fact that 
 the neighbouring Kaimenis did not participate in the move- 
 ment, still less the three more distant or outer islands. 
 
 Fig. 97 
 
 Bird's-eye view of the Gulf of Santorin during the volcanic eruption 
 of February, 1866. 
 
 a. Therasia. 
 
 b. The ' northern entrance,' 1 ,068 feet deep. 
 
 c. Thera. 
 
 d. Mount St. Elias, rising 1,887 feet above 
 the sea, composed of granular limestone and 
 clay-slate, the only non-volcanic rocks in 
 Santorin. 
 
 e. Aspronisi. 
 /. Little Kaimeni. 
 g. New Kaimeni. 
 h. Old Kaimeni. 
 t Aphroessa. 
 k. George. 
 
 Eruption of 1866. Another eruption broke out in Nea 
 Kaimeni in February 1866. At the end of January the sea 
 had been observed in a state of ebullition off the south-west 
 coast, and part of the channel between New and Old Kaimeni 
 marked 70 fathoms in the Admiralty chart had become, on 
 February 11, only 12 fathoms deep. According to M. Julius 
 Schmidt, a gradual rising of the bottom went on until 
 
70 SANTORIN". [Cii. XXVII. 
 
 a small island made its appearance called afterwards 
 Aphroessa.* (See i, fig. 97.) It seems to have consisted of 
 lava pressed upwards and outwards almost imperceptibly 
 by steam, which was escaping at every pore through the 
 hissing scoriaceous crust. ' It could be seen,' says Com- 
 mander Lindsay Brine, B.N., ' through the fissures in the cone 
 that the rocks within were red-hot, but it was not till later 
 that an eruption began.'f On February 11, the village of 
 Yulcano on the south-east coast, where there had been a 
 partial sinking of the ground, was in great part overwhelmed 
 by the materials cast out from a new vent which opened in 
 that neighbourhood, and to which the name of George was 
 given (see Jc, fig. 97), which finally, according to Schmidt, 
 became about 200 feet high. Commander Brine having 
 ascended on February 28, 1866, to the top of the crater of 
 Nea Kaimeni about 350 feet high, looked down upon the 
 new vent then in full activity. The whole of the cone was 
 swaying with an undulating motion to the right and left, and 
 appeared sometimes to swell to nearly double its size and 
 height, to throw out ridges like mountain spurs, till at last 
 a broad chasm appeared across the top of the cone, accom- 
 panied by a tremendous roar of steam, and the shooting up 
 from the new crater to the height of. from 50 to 100 
 feet of tons of rock and ash mixed with smoke and steam. 
 Some of these which fell on Micra-Kaimeni at a distance of 
 600 yards from the crater, measured 30 cubic feet. This 
 effort over, the ridges slowly subsided, the cone lowered and 
 closed in, and then, after a few minutes of comparative 
 silence, the struggle would begin again with precisely similar 
 sounds, action, and result. Threads of vapour escaping from 
 the old crater of Nea Kaimeni proved that there was a sub- 
 terranean connection between the old and new vents.' J 
 
 Aphroessa, of which the cone was at length raised to a 
 height of more than 60 feet, was united in August with the 
 main island. This was due in part at least to the upheaval 
 of the bottom of the sea, which is now only 7 fathoms 
 
 * Schmidt, cited by Von Hauer. Geographical Proc. Nov. 10th, 1866, 
 
 t Brine, Visit to Santorin. Royal vol. x. p. 317. J Ibid. 
 
CH. XXVII.] SANTORIN. 7 i 
 
 deep in the channel dividing the New and Old Kaimenis, 
 whereas in the Admiralty chart (see fig. 95) the soundings 
 gave 100 fathoms. 
 
 It will be seen by the map and section (figs. 95 and 96), 
 that the Kaimenis are arranged in a linear direction, running 
 NE. and SW., in a manner different from that represented 
 in the older charts. In their longest diameter they form at 
 their base a ridge nearly bisecting the gulf or crater. 
 
 Notwithstanding this linear arrangement we may compare 
 the three Kaimenis in the centre of the gulf to the modern 
 cone of Vesuvius, and consider the outer islands Thera, 
 Aspronisi, and Therasia as the remains of an older and 
 ruined cone like Somma. Thera, which constitutes alone 
 more than two-thirds of the outer circuit, presents everywhere 
 towards the gulf high and steep precipices composed of 
 volcanic rocks. In all places near the base of its cliffs, a 
 depth of from 800 to 1,000 feet of water was found, and 
 Lieut. Leycester informs us that if the gulf, which is 6 
 miles in diameter, could be drained, a bowl-shaped cavity 
 would appear with walls 2,449 feet high in some places, and 
 even on the south-west side, where it is lowest, nowhere less 
 than 1,200 feet high; while the Kaimenis would be seen to 
 form in the centre a huge mountain 5J miles in circum- 
 ference at its base, with three principal summits (the 
 Old, the New, and the Little Burnt Islands) rising severally 
 to the heights of 1,251, 1,629, and 1,158 feet above the 
 bottom of the abyss. The rim of the great cauldron thus 
 exposed would be observed to be in all parts perfect and 
 unbroken, except at one point where there is a deep and long 
 chasm or channel, known by mariners as the 'northern 
 entrance ' (B, fig. 95, and 6, fig. 97) between Thera and 
 Therasia, and called by Lieut. Leycester ( the door into the 
 crater.' It is no less than 1,1 70 feet deep, and constitutes, as 
 will appear by the soundings (see Map, fig. 95), a remarkable 
 feature in the bed of the sea. There is no corresponding 
 channel passing out from the gulf into the Mediterranean 
 at any other point in the circuit between the outer islands, 
 the greatest depth there ranging from 7 to 66 feet. 
 
 We may conceive, therefore, if at some former time the 
 
72 SANTORIN. [Cn. XXVII. 
 
 whole mass of Santorin stood at a higher level by 1,200 feet, 
 that this single ravine or narrow valley now forming ' the 
 northern entrance,' was the passage by which the sea entered 
 a circular bay. 
 
 But at a still earlier period when the ancient volcanic 
 cone, of which the outer islands are the remains, was still 
 more elevated above the level of the sea, there may have 
 been a deep valley of subaerial erosion cut by the principal 
 river which then drained Santorin, which may have con- 
 sisted of one lofty volcanic cone afterwards truncated by a 
 paroxsymal explosion such as we have already spoken of in 
 the case of Galongoon, p. 57, and when treating of the sup- 
 posed origin of the Val del Bove on Etna. It would then be 
 necessary to imagine the subsidence and partial submergence 
 of this original island in order to explain the present gulf and 
 the deep channel (B, fig. 95) coinciding with the ancient 
 gorge of fluviatile erosion. 
 
 All the outer islands Thera, Therasia, and Aspronisi are 
 covered with one great uniform mass of volcanic matter, 
 expressed by d, d', in the section fig. 96, p. 66. This great 
 overlying deposit has been called pumiceous by many ob- 
 servers, but M. Vhiet says it is a white tufaceous agglomerate 
 through which are dispersed fragments of a brown trachyte. 
 Such a mass may well be imagined to be the product of that 
 paroxysmal eruption by which so large a part of the great 
 cone was destroyed, and the gulf formed, in the middle of 
 which the Kaimenis have since been thrown up. 
 
 Thera, Therasia, and Aspronisi are exclusively composed 
 of volcanic matter, except the southern part of Thera, where 
 Mount St. Elias (d d, fig. 97) reaches an elevation of 1,887 
 feet above the sea, or three times the height now attained by 
 the loftiest of the igneous rocks .* This mountain is formed 
 of granular limestone and argillaceous schist, and is much 
 more ancient than any part of the volcanic cone, one side of 
 the base of which now abuts against it. The inclination, 
 strike, and fractures of the calcareous and argillaceous strata 
 of St. Elias have no relation to the great cone, but, according 
 
 * Virlet, Bull, cle la Soc. Geol. de "France, tome iii. p. 103. 
 
CH. XXVII.] SANTOEIN. 73 
 
 to M. Bory St. Vincent, have the same direction as those of 
 the other isles of the Grecian Archipelago, namely, from 
 NNW. to SSE. Each of the three islands, Thera, Therasia, 
 and Aspronisi, are composed of beds of trachytic lava and 
 tuff, having a gentle inclination of only 3 or 4. Each bed is 
 very narrow and discontinuous, the successive layers being 
 moulded or dove-tailed, as M. Virlet expresses it, into the in- 
 equalities of the previously existing surface, on which showers 
 of cinders or streams of melted matter had been poured. 
 
 An important fact is adduced by M. Yirlet, to show that 
 the gentle dip of the lava streams in the three outer islands 
 towards all points of the compass, away from the centre of 
 the gulf, has not been due to the upheaval of horizontal beds, 
 as conjectured by Von Buch, who had never visited Santorin.* 
 The French geologist found that the vesicles or pores of the 
 trachytic masses were lengthened out in the several directions 
 in which they would have flowed if they had descended from 
 the axis of a cone occupying the centre of the crater. For 
 it is well known that the bubbles of confined gas in a fluid in 
 motion assume an oval form, and the direction of their longer 
 axis coincides always with that of the stream. 
 
 The absence of dikes in the cliffs surrounding the gulf is 
 in favour of the theory that we here behold a section of 
 the basal remains of an old volcanic cone. We have already 
 spoken of the want of such dikes in those parts of the old 
 Vesuvius (see Vol. I. p. 635) or Somma, as well as of Mount 
 Etna, which are far from the original centres of eruption. 
 (Vol. II. p. 17.) We may confidently infer from analogy 
 that the missing part of the old cone of Santorin which rose 
 to a great height where the Kaimenis now stand, consisted 
 of steeply inclined lavas traversed by numerous vertical dikes. 
 
 If we adopt the hypothesis above suggested, we are re- 
 quired to assume a subsidence of more than 1,000 feet in 
 order to explain the north-east channel (B, fig. 95, and 6, fig. 
 97) as being a submerged valley or ravine of subaerial erosion. 
 In reference to this point we may mention that a large part 
 of Thera actually sank down during a great earthquake in 
 
 * Poggendorf s Annalen 1836, p. 183. 
 
74 BARREN ISLAND. [Cn. XXVIT. 
 
 1650, the subsidence being proved not only by tradition, but 
 by the fact that a road which formerly led between two 
 places on the east coast of Thera is now 12 fathoms under 
 water. A long succession, no doubt, of such events would be 
 demanded to bring about so great a submergence, and future 
 geologists will have to decide whether this or some other 
 theory will best account for this submarine chasm. 
 
 On a review, therefore, of ah 1 the facts now brought to light 
 respecting Santorin, I attribute the moderate slope of the 
 beds in Thera and the other external islands to their having 
 originally descended the inclined flanks of a large volcanic 
 cone, the principal orifice or vents of eruption having been 
 always situated where they are now, in or near the centre of 
 the space occupied by the gulf or crater, in other words where 
 the outburst of the Kaimenis has been witnessed in historical 
 times. The single long and deep opening into the crater is 
 a feature common to all those remnants of ancient volcanos, 
 the central portions of which have been removed, and is pro- 
 bably connected with aqueous denudation. As to the age of 
 the more ancient volcanic formations of Santorin, I am in- 
 formed by M. Fouque that they belong to the Newer Pliocene 
 period, as shown by marine shells which he collected in 1866.* 
 
 Barren Island. There is a great analogy between the 
 structure of Barren Island in the Bay of Bengal, lat. 12 15', 
 and that of Santorin last described. When seen from the 
 ocean, this island presents, on almost all sides, a surface of 
 bare rocks, rising, with a moderate acclivity, towards the in- 
 terior ; but at one point there is a cleft by which we can pene- 
 trate into the centre, and there discover that it is occupied by a 
 great circular basin more than 8,000 feet in diameter bordered 
 all around by steep rocks, in the midst of which rises a volcanic 
 cone, very frequently in eruption. The height of the circular 
 border which encloses the basin has been variously estimated. 
 According to Von Liebig, who visited the island in 1857, it 
 was about 1,000 feet high, corresponding in elevation to the 
 modern cone, so that the latter can only be seen from the sea 
 
 * Since the above was in print, have been published by Messrs. Fritsch, 
 splendid photographs and descriptions Reiss, and Stiibel. Triibner, London, 
 of the eruption of the Kaimenis in 1866 1867. 
 
CH. XXVII.] 
 
 MUD VOLCANOS. 
 
 by looking through the ravine. The sides of this cone slope 
 at angles of from 35 to 40. In some of the older accounts 
 the sea is described as entering the inner basin, but Yon 
 Liebig says it was excluded at the time of his visit, and that a 
 stream of black lava 10 feet high was traceable from the interior 
 
 Tig. 98. 
 
 Cone and crater of Barren Island, in the Bay of Bengal. Height of the central 
 cone (according to Capt. Miller, in 1834), 500 feet.* 
 
 to the outlet ; there was also on the sides of the passage or 
 inlet a raised beach 20 feet high, composed of volcanic tuff 
 and rolled pebbles, indicative of a modern upheaval of the 
 island to that extent. It is most probable that the exterior 
 enclosure of Barren Island (c, d, fig. 99) is nothing more than 
 
 Sea, 
 
 
 Fig. 99. 
 
 Supposed section of Barren Island, in the Bay of Bengal. 
 
 the remains of a truncated cone, c, a, b, d, a great portion of 
 which has been removed by explosion, which may have pre- 
 ceded the formation of the new interior cone/, e, g.-f 
 
 MUD VOLCANOS. 
 
 Of Iceland. Professor E. Bunsen, in his account of the 
 pseudo-volcanic phenomena of Iceland, describes many 
 valleys where sulphurous and aqueous vapours burst forth 
 with a hissing sound, from the hot soil formed of volcanic 
 tuff. In such spots a pool of boiling water is seen, in which 
 
 *. The annexed view is given by Von 
 Buch. Captain Horsburgh saw smoke 
 proceeding from the crater in 1803. 
 
 t Von Liebig Zeitschrift der Geo- 
 logischen Gesellschaft, vol. x. p. 303. 
 1858. 
 
7<> MUD VOLCANOS. [On. XXVII. 
 
 a bluish-black argillaceous paste rises in huge bubbles. 
 These bubbles on bursting throw the boiling mud to a height 
 of 15 feet and upwards, so that it accumulates in ledges 
 round the crater or basin of the spring. 
 
 Of Baku on the Caspian. The formation of a new mud 
 volcano was witnessed on November 27, 1827, at Tokmali, on 
 the peninsula of Abscheroii, east of Baku. Flames blazed up 
 to an extraordinary height, for a space of 3 hours, and con- 
 tinued for 20 hours more to rise about 3 feet above a crater, 
 from which mud was ejected. At another point in the same 
 district where flames issued, fragments of rock of large size 
 were hurled up into the air, and scattered around.*" 
 
 Of Sicily. At a place called Macaluba, near Girgenti in 
 Sicily, are several conical mounds from 10 to 30 feet in 
 height, with small craters at their summits, from which cold 
 water, mixed with mud and bitumen, is cast out. Bubbles 
 of carbonic acid and carburetted hydrogen gas are also dis- 
 engaged from these springs, and at certain periods with such 
 violence, as to throw the mud to the height of 200 feet. 
 These 'air volcanos,' as they are sometimes termed, are 
 known to have been in the same state of activity for the last 
 15 centuries ; and Dr. Daubeny imagines that the gases 
 which escape may be generated by the slow combustion of 
 beds of sulphur, which is actually in progress in the blue 
 clay, out of which the springs rise.f But as the gases are 
 similar to those disengaged in volcanic eruptions, and as they 
 have continued to stream out for so long a period, they may 
 perhaps be derived from a more deep-seated source. 
 
 Of Bella in India. In the district of Luss or Lus, south of 
 Beila, about 120 miles NW. of Cutch and the mouths of the 
 Indus (see Map, fig. 105, p. 98), numerous mud volcanos 
 are scattered over an area of probably not less than 1,000 
 square miles. Some of these have been well described by 
 Captain Hart, and subsequently by Captain Eobertson, who 
 has paid a visit to that region, and made sketches of them, 
 which he has kindly placed at my disposal. From one of 
 these the annexed view has been selected. These conical 
 
 * Humboldt's Cosmos. f Daubeny, Volcanos, p. 267. 
 
CH. XXVII.] NATURE OF SUBTERRANEAN IGNEOUS HOCKS. 77 
 
 hills occur to the westward of the Hara Mountains and the 
 river Hubb. (See Map, p. 98.) One of the cones is 400 
 feet high, composed of light-coloured earth, and having at 
 its summit a crater 30 yards in diameter. The liquid mud 
 which fills the crater is continually disturbed by air-bubbles, 
 and here and there is cast up in small jets.* 
 
 Fig. 100. 
 
 Mud cones and craters of Hinglaj near Bella, district of Lus, 120 miles north-west 
 of mouth of Indus. From original drawing by Capt. Robertson. (See Map. p. 98.) 
 
 Frequency of eruptions, and nature of subterranean igneous 
 rocks. When we speak of the igneous rocks of our own 
 times, we mean that small portion which, in violent erup- 
 tions, is forced up by elastic fluids to the surface of the 
 earth, the sand, scoriae, and lava, which cool in the open 
 air. But we cannot obtain access to that which is congealed 
 far beneath the surface under great pressure, equal to that 
 of many hundred, or many thousand atmospheres. 
 
 * SeeBuist, Volcanosof India, Trans. 
 Bombay Geol. Soc. vol. x. p. 154, and 
 
 Captain Robertson, Journ. of Roy. 
 Asiat. Soc. 1850. 
 
78 NATURE OF SUBTERRANEAN IGNEOUS ROCKS. [Cn. XXVII. 
 
 During the last century, about 50 eruptions are recorded 
 of the five European volcanic districts, of Vesuvius, Etna, 
 Volcano, Santorin, and Iceland ; but many beneath the sea 
 in the Grecian Archipelago and near Iceland may doubtless 
 have passed unnoticed. If some of them produced no lava, 
 others, on the contrary, like that of the Skaptar Jokul, in 
 1783, poured out melted matter for 5 or 6 years consecutively ; 
 which cases, being reckoned as single eruptions, will com- 
 pensate for those of inferior strength. Now, if we consider 
 the active volcanos of Europe to constitute about a fortieth 
 part of those already known on the globe, and calculate that, 
 one with another, they are about equal in activity to the 
 burning mountains in other districts, we may then compute 
 that there happen on the earth about 2,000 eruptions in the 
 course of a century, or about 20 every year. 
 
 However inconsiderable, therefore, may be the superficial 
 rocks which the operations of fire produce on the surface, we 
 must suppose the subterranean changes now constantly in 
 progress to be on the grandest scale. The loftiest volcanic 
 cones and the lavas which have flowed from their craters 
 must be insignificant when contrasted with the products of 
 fire in the nether regions. In regard to these last or those 
 igneous rocks which have been formed in our own times in 
 the bowels of the earth, whether in rents and caverns, or by 
 the cooling of lakes of melted lava, we may safely infer that 
 they are heavier and less porous than ordinary lavas, and 
 more crystalline, although composed of the same mineral 
 ingredients. As the hardest crystals produced artificially 
 in the laboratory require the longest time for their formation, 
 so we must suppose that where the cooling down of melted 
 matter takes place by insensible degrees, in the course of 
 ages, a variety of minerals will be produced far harder than 
 any formed by natural processes within the short period of 
 human observation. 
 
 These subterranean volcanic rocks, moreover, cannot be 
 stratified in the same manner as sedimentary deposits from 
 water, although it is evident that when great masses con- 
 solidate from a state of fusion, they may separate into 
 natural divisions; for this is seen to be the case in many 
 
CH. XXVII.] NATURE OF SUBTERRANEAN IGNEOUS ROCKS. 79 
 
 lava currents. We may also expect that the rocks in 
 question will often be rent by earthquakes, since these are 
 common in volcanic regions ; and the fissures will be often 
 injected with similar matter, so that dikes of crystalline 
 rock will traverse masses of similar composition. It is also 
 clear, that no organic remains can be included in such 
 masses, as also that these deep-seated igneous formations 
 considered in mass must underlie all the strata containing 
 organic remains, because the heat proceeds from below up- 
 wards, and the intensity required to reduce the mineral in- 
 gredients to a fluid state must destroy all organic bodies in 
 rocks included in the midst of them. 
 
 If by a continued series of elevatory movements, such 
 masses shall hereafter be brought up to the surface, in the 
 same manner as sedimentary marine strata have, in the 
 course of ages, been upheaved to the summit of the loftiest 
 mountains, it is not difficult to foresee what perplexing pro- 
 blems may be presented to the geologist. He may then, 
 perhaps, study in some mountain-chain the very rocks pro- 
 duced at the depth of several miles beneath the Andes, Ice- 
 land, or Java, in the time of Leibnitz, and draw from them 
 the same conclusion which that philosopher derived from 
 certain igneous products of high antiquity ; for he conceived 
 our globe to have been, for an indefinite period, in the state of 
 a comet, without an ocean, and uninhabitable alike by aquatic 
 or terrestrial animals. 
 
80 
 
 CHAPTEE XXVIII. 
 
 EARTHQUAKES AND THEIR EFFECTS. 
 
 EARTHQUAKES AND THEIR EFFECTS DEFICIENCY OF ANCIENT ACCOUNTS 
 ORDINARY ATMOSPHERIC PHENOMENA CHANGES PRODUCED BY EARTHQUAKES 
 IN MODERN TIMES CONSIDERED IN CHRONOLOGICAL ORDER EARTHQUAKE IN 
 
 NEW ZEALAND PERMANENT UPHEAVAL AND SUBSIDENCE OF LAND A FAULT 
 
 PRODUCED IN THE ROCKS EARTHQUAKE IN SYRIA, 1837 EARTHQUAKES IN 
 
 CHILI IN 1837 AND 1835 ISLE OF SANTA MARIA RAISED TEN FEET CHILI, 
 1822 EXTENT OF COUNTRY ELEVATED EARTHQUAKE OF CUTCH IN 1819 
 SUBSIDENCE IN THE DELTA OF THE INDUS ISLAND OF SUMBAWA IN 1815 
 EARTHQUAKE OF CARACCAS IN 1812 SHOCKS AT NEW MADRID IN 1811 IN 
 THE VALLEY OF THE MISSISSIPPI. 
 
 IN the sketch given in Chapter XXIII. of the geographical 
 boundaries of volcanic regions, I stated, that although the 
 points of eruption are but thinly scattered, constituting mere 
 spots on the surface of those vast districts, yet the sub- 
 terranean movements extend simultaneously over immense 
 areas. We may now proceed to consider the changes which 
 these movements produce on the surface, and in the internal 
 structure of the earth's crust. 
 
 Deficiency of ancient accounts. It is only within the last two 
 centuries, since Hooke first promulgated, in 1688, his views 
 respecting the connection between geological phenomena 
 and earthquakes, that the permanent changes effected by 
 these convulsions have excited attention. Before that time, 
 the narrative of the historian was almost exclusively confined 
 to the number of human beings who perished, the number of 
 cities laid in ruins, the value of property destroyed, or certain 
 atmospheric appearances which dazzled or terrified the ob- 
 servers. The creation of a new lake, the engulphing of a 
 city, or the raising of a new island, are sometimes, it is true, 
 adverted to, as being too obvious, or of too much geographical 
 or political interest to be passed over in silence. But no 
 
CH. XXVIII.] PHENOMENA ATTENDING EARTHQUAKES. 81 
 
 researches were made expressly with a view of ascertaining 
 the amount of depression or elevation of the ground, or any 
 particular alterations in the relative position of sea and land ; 
 and very little distinction was made between the raising of 
 soil by volcanic ejections, and the upheaving of it by forces 
 acting from below. The same remark applies to a very large 
 proportion of modern accounts : and how much reason we 
 have to regret this deficiency of information appears from 
 this, that in every instance where a spirit of scientific enquiry 
 has animated the e}^e-witnesses of these events, facts calcu- 
 lated to throw light on former modifications of the earth's 
 structure are recorded. 
 
 Phenomena attending earthquakes. As I shall confine myself 
 almost entirely, in the following notice of earthquakes, to the 
 changes brought about by them in the configuration of the 
 earth's crust, I may mention, generally, some accompani- 
 ments of these terrible events which are almost uniformly 
 commemorated in history, so that it may be unnecessary to 
 advert to them again. Irregularities in the seasons preceding 
 or following the shocks ; sudden gusts of wind, interrupted 
 by dead calms; violent rains at unusual seasons, or in 
 countries where such phenomena are almost unknown; a 
 reddening of the sun's disk, and haziness in the air, often 
 continued for months ; an evolution of electric matter, or of 
 inflammable gas from the soil, with sulphurous and mephitic 
 vapours ; noises underground, like the running of carriages, 
 or the discharge of artillery, or distant thunder; animals 
 uttering cries of distress, and evincing extraordinary alarm, 
 being more sensitive than men of the slightest movement ; a 
 sensation like sea-sickness, and a dizziness in the head, ex- 
 perienced by men : these, and other phenomena, less con- 
 nected with our present subject as geologists, have recurred 
 again and again at distant ages, and in all parts of the 
 globe. 
 
 I shall now begin the enumeration of earthquakes with 
 the latest authentic narratives, and so carry back the survey 
 retrospectively, that I may bring before the reader, in the 
 first place, the minute and circumstantial details of modern 
 times, and thus enable him, by observing the extraordinary 
 
 VOL. n. G 
 
82 EARTHQUAKES OF THE NINETEENTH CENTURY. [Cn. XXVIII. 
 
 amount of change within the last 1 70 years, to perceive how 
 great must be the deficiency in the meagre annals of earlier 
 eras. 
 
 EARTHQUAKES OF THE NINETEENTH CENTURY.* 
 
 New Zealand, 1855. Permanent upheaval and subsidence of 
 land. In no country perhaps, where the English language 
 is spoken, have earthquakes, or, to speak more correctly, the 
 subterranean causes to which such movements are due, been 
 so active in producing changes of geological interest as in 
 New Zealand. The convulsions which have agitated this 
 archipelago since it was first known to whalers or settlers, 
 have visited different districts in succession. 
 
 The Rev. R. Taylor, many years a missionary in New 
 Zealand, states that the shocks of 1826, 1841, and 1843 
 expended each of them their chief violence in distinct areas. 
 In the year 1823, there was a small cove called the Jail, 
 about 80 miles north of Dusky Bay, much visited by sealers, 
 for it afforded suitable anchorage for their vessels, being 
 sheltered by lofty cliffs, and having deep water so close to 
 the shore that they could step out of their boats on to the 
 rocks. 
 
 After a succession of earthquakes in 1826 and 1827, so 
 complete was the transformation of this coast that its former 
 features could no longer be recognised ; the cove had become 
 dry land, and trees were seen under water near the coast, 
 having probably been carried down by landslips into what 
 
 * Since the publication of the first miralty Manual, 1849; also Mr. Mallet's 
 edition of this work, numerous accounts reports on earthquakes to Brit, Assoc. 
 of recent earthquakes have been pub- 1850, 1852, and 1858, containing a 
 lished ; but as they do not illustrate any complete catalogue of known earth- 
 new principle, I cannot insert them, as quakes from 1606 B.C. to A.D. 1842; 
 they would enlarge too much the size of also remarks on the earthquakes of 
 my work. The late Von Hoflf published which accounts were published since 
 from time to time, in Poggendorfs An- that time by Prof. Alexis Perrey, of 
 naleu, lists of earthquakes which hap- Dijon. A continued series of accounts 
 pened between 1821 and 1836 ; and, by of earthquakes and volcanic eruptions 
 consulting these, the reader will perceive by the last-mentioned author, drawn up 
 that every month is signalised by one with great care, since 1842, has been 
 or many convulsions in some part of the published by the Eoyal Academy of 
 globe. See also Mallet's Dynamics of Belgium, with the discussion of their 
 Earthquakes, Trans. Hoy. Irish Acad. causes and effect. See also Hopkins' 
 1846; also Art. 'Earthquakes,' Ad- Report, Brit, Assoc. 1847-8. 
 
CH. XXVIII.] THOSE OF NEW ZEALAND. 83 
 
 was previously deep water, for large masses are said to have 
 slid down from the hills into the sea. The same writer 
 informs us, that in 1847, the hull of a vessel was discovered 
 on the western coast of the South Island. It was lying 200 
 yards inland, and was supposed to be the ' Active,' which was 
 lost in 1814. A small tree was growing through its bottom, 
 and Mr. Taylor suggests that the coast had risen, so as to 
 cause the ocean to retire to a distance of 200 yards from the 
 old shore line, where the vessel had been stranded ; but a 
 more precise investigation of the locality will be required 
 before we can feel sure that the vessel was not carried in by 
 ^a wave raised during the earthquake, for such waves have, 
 in modern times, left much larger ships high and dry in 
 the interior of Peru and some other countries.* (See p. 157.) 
 The natives are said to have told our first settlers that they 
 might expect a great earthquake every seven years ; and 
 although such exact periodicity has by no means been veri- 
 fied, the average number of violent shocks in a quarter of a 
 century seems not to have fallen short of the estimate here 
 referred to. 
 
 In the course of the year 1856, I had an opportunity of 
 conversing in London with three gentlemen, all well qualified 
 as scientific observers, who were eye-witnesses of the tremen- 
 dous earthquake experienced in January of the preceding* 
 year in New Zealand. These were, Mr. Edward Eoberts, of 
 the Eoyal Engineers department ; Mr. Walter Mantell, son 
 of the celebrated geologist; and Mr. Frederick A. Weld, a 
 landed proprietor in the South Island.f The earthquake 
 occurred in the night of January 23, 1855, and was most 
 violent in the narrowest part of Cook Strait, a few miles to 
 the SE. of Port Nicholson, (see Map, fig. 101) ; but the 
 shocks were felt by ships at sea 150 miles from the coast, 
 and the whole area shaken of land and water is esti- 
 mated at 360,000 square miles, an area three times as large 
 as the British Isles. In the vicinity of Wellington, in the 
 North Island, a tract of land comprising 4,600 square miles 
 
 * Rev. R. Taylor, ' New Zealand and in the Bulletin de la Soc. Geol. de 
 its Inhabitants/ London, 1855. France, 1856, p. 661. 
 
 t This account was published by me 
 
 G 2 
 
84 EARTHQUAKES OF THE NINETEENTH CENTURY. [On. XXVIIL 
 
CH. XXVIII.] EARTHQUAKES IN NEW ZEALAND. 85 
 
 (not much, inferior to Yorkshire in dimensions), is supposed 
 by Mr. Roberts to have been permanently upraised from. 1 to 
 9 feet. There was no perceptible elevation on the coast 16 
 miles N. of Wellington, but from that point to Pencarrow 
 Head, on the east side, at the entrance of Port Mcholson, 
 (see Map, fig. 101), the amount of upheaval went on increasing 
 somewhat gradually, till it reached a vertical height of 9 feet 
 along the eastern flank of the Remutaka Mountains. This 
 range terminates in Cook Strait, between Port Nicholson 
 and Palliser Bay, in a lofty coast rising rapidly to heights 
 about 4,000 feet above the sea. Here the vertical movement 
 ceased abruptly along the base of these hills, not affecting 
 the low country to the eastward, 6, fig. 102, called the Plain 
 of Wairarapa. The points of minimum and maximum eleva- 
 tion, from NW. to SE., in the district above alluded to, 
 are about 23 miles apart, which therefore expresses the 
 breadth of the upraised area. Mr. Roberts was employed 
 professionally, before and after January 23, in executing 
 several government works in the harbour of Port Mcholson 
 and on the coast, and had occasion to observe minutely the 
 changes in the level of the land, which took place at various 
 points, and especially in 
 the sea-cliff, called Muka- A 
 Muka, 12 miles SE. of 
 Wellington, where the 
 eastern flank of the Reniu- 
 taka range, before de- 
 scribed, terminates south- 
 Junction of argillite and tertiary strata at 
 
 wards in Cook Strait. Here Muka-Muka cliff.* 
 
 a distinct line Of fault, C, d, A. Argillite. c, d. Line of vertical 
 
 B. Tertiary strata. fissure and fault. 
 
 fig. 102, was observed, the 
 
 rocks on one side A, being raised vertically 9 feet, while 
 the strata B, on the other side of the fissure c, d, experienced 
 no movement. The uplifted mass A consists, according 
 to Mr. Walter Mantell, of argillite, having the ordinary 
 composition of clay state, but not laminated. It presents 
 a cliff, several hundred feet high towards the straits, whereas 
 
 "" * I give this section from the de- therefore be simply regarded as an ex- 
 scription of my informants, and it must planatorv diagram. 
 
86 EARTHQUAKES OF THE NINETEENTH CENTURY. [Cn. XXVIII. 
 
 tlis horizontally stratified tertiary strata exposed to the 
 eastward form a comparatively low cliff, not exceeding 80 
 feet in height. These tertiary strata, which are of marine 
 origin, did not, as already stated, participate in the upward 
 movement. Mr. Eoberts was able to measure accurately the 
 amount of permanent upheaval in the older formation, by 
 observing the altered position of a white band of nullipores, 
 with which the surface of the rock below the level of low tide 
 had been coated. This white zone, a few hours after the 
 earthquake, was found to be 9 feet above its former level. 
 Previously to the shock, there had been no room to pass 
 between the sea and the base of the perpendicular cliff 
 called Muka-Muka, except for a short time at low water, and 
 as the herdsmen were obliged to wait for low tide in order 
 to drive their cattle past the cliff, Mr. Koberts was engaged 
 in constructing a road there. But immediately after the 
 upheaval, a gently sloping raised beach, more than 100 feet 
 wide, was laid dry, affording ample space at all states of the 
 tide for the passage of man and beast. 
 
 The junction of the older and newer rocks along the line 
 of fault above described is marked in the interior of the 
 country by a continuous escarpment running north and south 
 along the base of the Eemutaka Mountains, where they 
 present a steep slope towards the east, or towards the great 
 plain of the Wairarapa formed of the modern tertiary deposit 
 before mentioned. The course of the fault along the base of 
 the escarpment was rendered visible by a nearly perpendicular 
 cliff of fresh aspect 9 feet in height and traceable in an 
 inland direction to the extraordinary distance of about 90 
 miles, according to information given by Mr. Borlase, a 
 settler who lived in the Wairarapa valley about 60 miles 
 north of Cook Strait. It was marked, moreover, in many 
 places by an open fissure into which cattle fell and could not 
 in some cases be recovered, or by fissures from 6 to 9 feet 
 broad filled here and there with soft mud and loose earth. 
 At the same time that this vertical movement took place on 
 January 23, the harbour of Port Nicholson, about 12 miles to 
 the westward of Muka-Muka cliff, together with the valley of 
 the Hutt, was raised from 4 to 5 feet, the greater elevation 
 
CH. XXVIII.] EARTHQUAKE IN NEW ZEALAND. 87 
 
 being on the eastern, and the lesser on the western side of 
 the harbour. A rock called the Bailey Eock, a short distance 
 from Evans Bay, was formerly 2 feet under water at the 
 lowest tides, and a vessel having touched upon it, a buoy had 
 been placed over it, to mark its position. This rock projected 
 after the shock nearly 3 feet above the surface of the water 
 at low tide. The rise of the tide in the Hutt Eiver was 
 sensibly diminished by the earthquake. At the time of the 
 convulsion great waves of the sea rolled in upon the coast, 
 and for several weeks the tides were very irregular. Dead 
 fish were left by a wave on the racecourse at Wellington, and 
 Mr. Mantell states that others were also met with by several 
 vessels in Cook Strait floating on the sea in surprising 
 numbers, some of them of species never seen before by the 
 fishermen. 
 
 Mr. Weld, who resided south of the straits in the South 
 Island, informed me that, besides experiencing there the shock 
 of the 2 3rd, he felt another next morning of equal violence, 
 and waves of the sea rolled in along the coast for a distance 
 of 50 miles. At a place called the Flags between Cape 
 Campbell and Waipapa (see Map), some men were loading a 
 vessel with wood, when they saw distinctly an earthquake 
 approaching them from a point called ' the White Rocks,' 
 3 miles to the northward. Its approach was rendered visible 
 by the rolling of stones from the top of the cliffs, also by 
 landslips and clouds of dust, and by the accompanying sea 
 wave. Upon the whole it appears that the area convulsed in 
 the South Island was not so extensive as that upheaved 
 around Wellington, also that to the south of the Straits the 
 direction of the movement was reversed, being for the most 
 part a downward one. The valley of the Wairau, with parts 
 of the adjoining coast, subsided about 5 feet, so that the tide 
 flowed several miles farther up into the Wairau Eiver than it 
 formerly did, and ships taking in fresh water were obliged to 
 go three miles farther up the river to obtain a supply than 
 they did before the earthquake. 
 
 There was no volcanic eruption, whether in the Northern 
 or Southern Island at the time of these events ; but the 
 natives allege that the temperature of the Taupo hot springs 
 
88 EARTHQUAKES OF THE NINETEENTH CENTURY. [Cn. XXVIII. 
 
 (see small Map, fig. 101) was sensibly elevated, just before the 
 catastrophe. 
 
 I will now conclude this sketch of the changes produced 
 in 1855 by observing that a question arose as to whether 
 in the region about Port Nicholson the land, after it was 
 upheaved several feet in January, sank again to some slight 
 extent or a few inches in the course of 7 or 8 months, or 
 before September 1855. When Mr. Roberts left New Zealand, 
 three months after the earthquake, there had been no sinking 
 of the upraised land, and he felt persuaded that he could not 
 have failed to notice even a slight change of level had any 
 occurred. He ascertained ten weeks after the shock that there 
 had certainly been no subsidence whatever on the coast at 
 Pencarrow Head, and the tides were so irregular long after the 
 earthquake, in the harbour of Port Nicholson and elsewhere, 
 that the supposed partial sinking of the coast which some 
 believed to have taken place might perhaps be deceptive. It is 
 surprising how soon the signs of a recent change of level on a 
 coast are effaced to all eyes but those of the scientific observer, 
 especially where there is a rise and fall of the tides. Rocks 
 newly exposed soon begin to weather and vegetation spreads 
 over the emerged land, and a new beach, with all the charac- 
 ters of the old one, is formed in a few months along the 
 sea-margin. 
 
 The geologist has rarely enjoyed so good an opportunity 
 as that afforded him by this convulsion in New Zealand, 
 of observing one of the steps by which those great dis- 
 placements of the rocks called c faults ' may in the course of 
 ages be brought about. The manner also in which the 
 upward movement increased from north-west to south-east 
 explains the manner in which beds may be made to dip more 
 and more in a given direction by each successive shock. 
 
 An independent witness of the earthquake of January 1855, 
 a civil engineer, says in a letter to Mr. Robert Mallet that ( the 
 first and greatest shock of January 23 lasted about a minute 
 and a half. All the brick buildings in Wellington were 
 overthrown, as well as the bridge over the Hutt. The hillsides 
 opposite Wellington, those of the Remutaka range, were much 
 shaken, as evidenced by the many bare patches with which 
 
CH. XXVIII.] EARTHQUAKES IN SYRIA AND CHILI IN 1837. 89 
 
 they were chequered, fully to the extent of one-third of their 
 surface, whence trees had been shaken off.' The ground in 
 this range, he says, was more violently shaken than in 
 Wellington, and the direction of the shock was NE. and SW., 
 agreeing with that of the chain of hills. After the shock the 
 tide did not come at high water within 3 or 4 feet of its 
 former height.* 
 
 Mr. Weld was in the South Island during the previous 
 earthquake of 1848, and he informed me that a great rent was 
 then caused in a chain of mountains varying in height from 
 1,000 to 4,000 feet, which run southwards from the White 
 Bluff in Cloudy Bay and may be considered a prolongation of 
 the Remutaka or Tararua chain above alluded to. (See Map.) 
 This fissure of 1848 was not more than 18 inches in average 
 width, but was remarkable for its length, for it was partly 
 traced by Mr. Weld and partly by observers on whom he 
 could rely, for 60 miles, striking north-north-east and south- 
 south-west in a line parallel to the axis of the chain. 
 
 Syria, January, 1837. It has been remarked that earth- 
 quakes affect elongated areas. The violent shock which 
 devastated Syria in 1837 was felt on a line 500 miles in 
 length by 90 in breadth :f more than 6,000 persons perished; 
 deep rents were caused in solid rocks, and new hot springs 
 burst out at Tabereah. 
 
 Chili Valdivia, 1837. One of the earthquakes by which 
 in the present century the position of land is known to have 
 been permanently altered is that which occurred in Chili, on 
 November 7, 1837. On that day Yaldivia was destroyed, 
 and a whaler, commanded by Captain Coste, was violently 
 shaken at sea, and lost her masts, in lat. 43 38' S. in sight 
 of the land. The captain went on December 11 following to 
 a spot near the island of Lemus, one of the Chonos archi- 
 pelago, where he had anchored two years before, and found 
 that the bottom of the sea had been raised more than 8 feet. 
 Some rocks formerly covered at all times by the sea were 
 now constantly exposed, and an enormous quantity of shells 
 and fish in a decaying state, which had been thrown there 
 
 * Reports of Brit. Assoc. 1858, p. 105. 
 
 t Darwin, Geol. Proceedings, vol. ii. p. 658. 
 
90 EAKTHQUAKES OF THE NINETEENTH CENTURY. [On. XXVIII. 
 
 by the waves, or suddenly laid dry during the earthquake, 
 attested the recent date of the occurrence. The whole coast 
 was strewed with uprooted trees.* 
 
 Chili Conception, 1835. Fortunately we have a still 
 more detailed account of the geographical changes produced 
 in the same country on February 20, 1835. An earthquake 
 was then felt at all places between Copiapo and Chiloe, 
 nearly 1,000 miles from north to south, and from Mendoza to 
 Juan Fernandez, about 500 miles from east to west. ' Vessels,' 
 says Mr. Caldcleugh, ( navigating the Pacific, within 100 
 miles of the coast, experienced the shock with considerable 
 force, 'f Conception, Talcahuano, Chilian, and other towns, 
 were thrown down. From the account of Captain Fitz Roy, 
 E.N., who was then employed in surveying the coast, we 
 learn that after the shock the sea retired in the Bay of 
 Conception, and the vessels grounded, even those which had 
 been lying in seven fathoms water : all the shoals were visible, 
 and soon afterwards a wave rushed in and then retreated, and 
 was followed by two other waves. The vertical height 
 of these waves does not appear to have been much greater 
 than 16 or 20 feet, although they rose to much greater 
 heights when they broke upon a sloping beach. 
 
 According to Mr. Caldcleugh and Mr. Darwin, the whole 
 volcanic chain of the Chilian Andes, a range 150 miles in 
 length, was in a state of unusual activity, both during the 
 shocks and for some time preceding and after the convulsion, 
 and lava was seen to flow from the crater of Osorno. (See 
 Map, fig. 103.) The island of Juan Fernandez, distant 365 
 geographical miles from Chili, was violently shaken at the 
 same time, and devastated by a great wave. A submarine 
 volcano broke out there near Bacalao Head, about a mile 
 from the shore, in 69 fathoms water, and illumined the 
 whole island during the night. { 
 
 ( At Conception,' says Captain Fitz Roy, c the earth opened 
 and closed rapidly in numerous places. The direction of the 
 cracks was not uniform, though generally from south-east to 
 
 * Dumoulin, Comptes Eendus de f Phil. Trans. 1836, p. 21. 
 
 1'Acad. des Sci. Oct. 1838, p. 706. J Ibid. 1826. 
 
CH. XXVIII.] EAKTHQUAKES IN CHILI. 91 
 
 Fig. 103. 
 
 35- 
 
 north-west. The earth was not quiet for three days after the 
 great shock, and more than 300 shocks were counted between 
 February 20 and March 4. The loose earth of the valley of 
 
92 EARTHQUAKES OF THE NINETEENTH CENTURY. [Cn. XXVIII. 
 
 the Biobio was everywhere parted from, the solid rocks which 
 bound the plain, there being an opening between them from 
 an inch to a foot in width. 
 
 6 For some days after February 20, the sea at Talcahuano,' 
 says Captain Fitz Roy, ' did not rise to the usual marks by 
 4 or 5 feet vertically. When walking on the shore, even 
 at high water, beds of dead mussels, numerous chitons, and 
 limpets, and withered sea-weed, still adhering, though life- 
 less, to the rocks on which they had lived, everywhere met 
 the eye.' But this difference in the relative level of the land 
 
 Fig. 104. 
 
 Part of Chili altered by Earthquake of February, 1835. 
 
 and sea gradually diminished, till in the middle of April the 
 water rose again to within 2 feet of the former highwater 
 mark. It might be supposed that these changes of level 
 merely indicated a temporary disturbance in the set of the 
 currents or in the height of the tides at Talcahuano ; but, on 
 considering what occurred in the neighbouring island of Santa 
 Maria, Captain Fitz Eoy concluded the land had been raised 
 4 or 5 feet in February, and that it had returned in April 
 to within 2 or 3 feet of its former level. 
 
CH. XXYIIL] EARTHQUAKES IN CHILI AND ISCHIA. 93 
 
 Santa Maria, the island just alluded to, is about 7 
 miles long and 2 broad, and about 25 miles south-west of 
 Conception. (See Map, fig. 104.) The phenomena observed 
 there are most important. 'It appeared,' says Captain 
 Fitz Roy, who visited Santa Maria twice, the first time 
 at the end of March, and afterwards in the beginning 
 of April, 'that the southern extremity of the island had 
 been raised 8 feet, the middle 9, and the northern end 
 upwards of 10 feet. On steep rocks, where vertical measures 
 could be correctly taken, beds of dead mussels were found 10 
 feet above high-water mark. 
 
 6 An extensive rocky flat lies around the northern parts of 
 Santa Maria. Before the earthquake this flat was covered 
 by the sea, some projecting rocks only showing themselves. 
 Now, the whole flat is exposed, and square acres of it are 
 covered with dead shell-fish, the stench arising from which 
 is abominable. By this elevation of the land the southern 
 port of Santa Maria has been almost destroyed ; little shelter 
 remaining there, and very bad landing.' The surrounding 
 sea is also stated to have become shallower in exactly the 
 same proportion as the land had risen ; the soundings having 
 diminished a fathom and a half everywhere around the island. 
 At Tubal, also, to the south-east of Santa Maria, the land 
 was raised 6 feet, at Mocha 2 feet, but no elevation could 
 be ascertained at Yaldivia. 
 
 Among other effects of the catastrophe, it is stated that 
 cattle standing on a steep slope, near the shore, were rolled 
 down into the sea, and many others were washed off by the 
 great wave from low land and drowned.*" 
 
 In November of the same year (1835), Conception was 
 shaken by a severe earthquake, and on the same day Osorno, 
 at the distance of 400 miles, renewed its activity. These 
 facts prove not only the connection of earthquakes with 
 volcanic eruptions in this region, but also the vast extent of 
 the subterranean areas over which the disturbing cause acts 
 simultaneously. 
 
 Ischia, 1828. On February 2, the whole island of Ischia 
 
 * Darwin's Jonrn. of Travels in South America, Voyage of 'Beagle,' p. 372. 
 
94 EARTHQUAKES OF THE NINETEENTH CENTURY. [Cn. XXVIII. 
 
 was shaken by an earthquake, and in the October following 
 I found all the houses in Casamicciol still without their roofs. 
 On the sides of a ravine between that town and Forio, I saw 
 masses of greenish tuff which had been thrown down. The 
 hot-spring of Rita, which was nearest the centre of the move- 
 ment, was ascertained by M. Covelli to have increased in 
 temperature, showing, as he observes, that the explosion took 
 place below the reservoirs which heat the thermal waters.* 
 
 Bogota, 1827. On November 16, 1627, the plain of Bogota, 
 in New Granada, or Colombia, was convulsed by an earth- 
 quake, and a great number of towns were thrown down. 
 Torrents of rain swelled the Magdalena, sweeping along vast 
 quantities of mud and other substances, which emitted a 
 sulphurous vapour and destroyed the fish. Popayan, which 
 is distant 200 geographical miles SSW. of Bogota, suffered 
 greatly. Wide crevices appeared in the road of Guanacas, 
 leaving no doubt that the whole of the Cordilleras sustained 
 a powerful shock. Other fissures opened near Costa, in the 
 plains of Bogota, into which the river Tunza immediately 
 began to flow.f Extraordinary rains accompanied the shocks 
 before mentioned ; and two volcanos are said to have been in 
 eruption in the mountain-chain nearest to Bogota. 
 
 Chili, 1822. On November 19, 1822, the coast of Chili 
 was visited by a most destructive earthquake. The shock 
 was felt simultaneously throughout a space of 1,200 miles 
 from north to south. St. Jago, Valparaiso, and some other 
 places, were greatly injured. When the district round 
 Valparaiso was examined on the morning after the shock, it 
 was found that the coast for a considerable distance was 
 raised above its former level. J At Valparaiso, the elevation 
 was 3 feet, and at Quintero about 4 feet. Part of the bed 
 of the sea, says Mrs. Graham, remained bare and dry at 
 high water, ' with beds of oysters, mussels, and other shells 
 adhering to the rocks on which they grew, the fish being all 
 dead, and exhaling most offensive effluvia. 
 
 An old wreck of a ship, which before could not be ap- 
 
 * Biblioth. Univ. Oct. 1828, p. 175. Journ. of Sci. 1824, vol. xvii. p. 40. 
 f Phil. Mag. July, 1828, p. 37. G-eol.. Trans, vol. i. 2nd ser. p. 
 
 Geol. Trans, vol. i. 2nd ser., and 415. 
 
CK. XXVIII.] EAETHQUAKES IN CHILI IN 1822. 95 
 
 preached, became accessible from the land, although its 
 distance from the original sea-shore had not altered. It was 
 observed that the watercourse of a mill, at the distance of 
 about a mile from the sea, gained a fall of 14 inches in little 
 more than 100 yards ; and from this fact it is inferred that 
 the rise in some parts of the inland country was far more 
 considerable than on the borders of the ocean.* Part of the 
 coast thus elevated consisted of granite, in which parallel 
 fissures were caused, some of which were traced for a mile 
 and a half inland. Cones of earth about 4 feet high were 
 thrown up in several districts, by the forcing up of water 
 mixed with sand through funnel-shaped hollows, a pheno- 
 menon very common in Calabria, and the explanation of 
 which will hereafter be considered. Those houses in Chili of 
 which the foundations were on rock were less damaged than 
 such as were built on alluvial soil. 
 
 Mr. Cruickshanks, an English botanist, who resided in the 
 country during the earthquake, has informed me that some 
 rocks of greenstone at Quintero, a few hundred yards from 
 the beach, which had always been under water till the shock 
 of 1822, have since been uncovered when the tide is at half- 
 ebb ; and he states that, after the earthquake, it was the 
 general belief of the fishermen and inhabitants of the Chilian 
 coast, not that the land had risen, but that the ocean had 
 permanently retreated. 
 
 Dr. Meyen, a Prussian traveller, who visited Valparaiso in 
 1831, says that on examining the rocks both north and south 
 of the town, nine years after the event, he found, in corrobo- 
 ration of Mrs. Graham's account, that remains of animals, 
 and sea-weed, the Lessonia of Bory de St. Vincent, which 
 has a firm ligneous stem, still adhered to those rocks which 
 in 1822 had been elevated above high-water mark.f Ac- 
 cording to the same author, the whole coast of Central Chili 
 was raised about 4 feet, and banks of marine shells were laid 
 dry on many parts of the coast. He observed similar banks, 
 elevated at unknown periods, in several places, especially at 
 Copiapo, where the species all agree with those now living in 
 
 * Journ. of Sci. vol. xvii. p. 42. Meyen's letter cited Foreign Quart. Eev. 
 
 t Eeise um die Erde; and see Dr. No. 33. p. 13. 1836. 
 
96 EAETH QUAKES OF THE NINETEENTH CENTURY. [On. XXVIII. 
 
 the ocean. Mr. Freyer also, who resided some years in 
 South America, has confirmed these statements ; * and Mr. 
 Darwin obtained evidence that the remains of an ancient 
 wall, formerly washed by the sea, and now 11 J feet above 
 high-water mark, acquired several feet of this elevation 
 during the earthquake of 1822. f 
 
 The shocks continued up to the end of September 1823 ; 
 even then, 48 hours seldom passed without one, and some- 
 times two or three were felt during 24 hours. Mrs. Graham 
 observed, after the earthquake of 1822, that besides a beach 
 newly raised above high-water mark, there were several older 
 elevated lines of beach, one above the other, consisting of 
 shingle mixed with shells extending in a. parallel direction to 
 the shore, to the height of 50 feet above the sea. J 
 
 Extent of country elevated. By some observers it has been 
 supposed that the whole country from the foot of the Andes 
 to a great distance under the sea was upraised in 1822, the 
 greatest rise being at the distance of about 2 miles from the 
 shore. c The rise upon the coast was from 2 to 4 feet: at 
 the distance of a mile inland it must have been from 5 to 6 
 or 7 feet.' It has also been conjectured by the same eye- 
 witnesses to the convulsion, that the area over which this 
 permanent alteration of level extended may have been equal 
 to 100,000 square miles. Although the increased fall of 
 certain watercourses may have afforded some ground for 
 this conjecture, it must be considered as very hypothetical, 
 and the estimate may have exceeded or greatly fallen short 
 of the truth. It may nevertheless be useful to reflect on the 
 enormous amount of change which this single convulsion 
 occasioned, if the extent of country moved upward really 
 amounted to 100,000 square miles, an extent just equal to 
 half the area of France, or about five-sixths of the area of 
 Great Britain and Ireland. If we suppose the elevation to 
 have been only 3 feet on an average, it will be seen that the 
 mass of rock added to the continent of America by the move- 
 ment, or, in other words, the mass previously below the leve 
 
 * Geol. Soc. Proceedings, No. xl. \. Greol. Trans, vol. i. 2nd ser. p. 415. 
 
 p. 179, Eeb. 1835. Journal of Science, vol. xvii. pp. 
 
 t Proceed. Geol. Soc. vol. ii. p. 447. 40, 45. 
 
CH. XXVIIL] COAST OF CHILI ELEVATED. 97 
 
 of the sea, and after the shocks permanently above it, must 
 have contained 57 cubic miles in bulk ; which would be 
 sufficient to form a conical mountain 2 miles high (or about 
 as high as Etna),, with a circumference at the base of nearly 
 33 miles. We may take the mean specific gravity of the 
 rock at 2*655, a fair average, and a convenient one in such 
 computations, because at such a rate a cubic yard weighs 2 
 tons. Then, assuming the great pyramid of Egypt, if solid, 
 to weigh, in accordance with an estimate before given, 
 6,000,000 tons, we may state the rock added to the continent 
 by the Chilian earthquake to have more than equalled 
 100,000 pyramids. 
 
 But it must always be borne in mind that the weight of 
 rock here alluded to constituted but an insignificant part of 
 the whole amount which the volcanic forces had to overcome. 
 The thickness of rock between the surface of Chili and the 
 subterranean foci of volcanic action may be many miles or 
 leagues deep. Say that the thickness was only 2 miles, even 
 then the mass which changed place and rose 3 feet, being 
 200,000 cubic miles in volume, must have exceeded in weight 
 363,000,000 pyramids. 
 
 It may be instructive to consider these results in connection 
 with others already obtained from a different source, and to 
 compare the working of two antagonist forces the levelling 
 power of running water, and the expansive energy of sub- 
 terranean heat. How long, it may be asked, would the Ganges 
 require, according to data before explained (Vol. I. p. 481), 
 to transport to the sea a quantity of solid matter equal to 
 that which may have been added to the land by the Chilian 
 earthquake ? The discharge of mud in one year by the Ganges 
 was estimated at 20,000,000,000 cubic feet. According to 
 that estimate it would require about 4 centuries (or 418 
 years) before the river could bear down from the continent 
 into the sea a mass equal to that gained by the Chilian 
 earthquake. In about half that time, perhaps, the united 
 waters of the Ganges and Burrampooter might accomplish 
 the operation. 
 
 Cutch, 1819. A violent earthquake occurred at Cutch, in 
 the delta of the Indus, on June 16, 1819. (See Map, fig. 105.) 
 
 VOL. II. H 
 
98 
 
 EARTHQUAKES IX THE NINETEENTH CENTURY. [Cn. XXVIII. 
 
 The principal town, Bhooj, was converted into a heap of 
 ruins, and its stone buildings were thrown down. The move- 
 ment was felt over an area having a radius of 1,000 miles 
 from Bhooj, and extending to Khatniandpo, Calcutta, and 
 Pondicherry.* The vibrations were felt in North-west 
 India, at a distance of 800 miles, after an interval of about 
 15 minutes after the earthquake at Bhooj. At Ahmedabad 
 the great mosque, erected by Sultan. Ahmed nearly 450 years 
 
 MAP 
 of 
 
 THE COUNTRIES 
 
 at 
 
 THE MOUTH OF THE 
 INDUS 
 
 Areas submerged during 
 earthquakes. 
 
 f he Runn, alternately land 
 and water. 
 
 before, fell to the ground, attesting how long a period had 
 elapsed since a shock of similar violence had visited that 
 point. At An jar, the fort, with its tower and guns, were 
 hurled to the ground in one common mass of ruin. The 
 shocks continued until the 20th ; when, 30 miles north-west 
 from Bhooj, the volcano called Denodur is said by some to 
 have sent forth flames, but Captain Grant, when in Cutch in 
 1838, was unable to authenticate this statement. 
 
 *. See Asiatic Journal, vol. i. 
 
CH. XXVIII.] SUBSIDENCE IN THE DELTA OF THE INDUS. 90 
 
 Subsidence in the delta of the Indus. Although the ruin of 
 towns was great, the face of nature in the inland country, 
 says Captain Macmurdo, was not visibly altered. In the 
 hills some large masses only of rock and soil were detached 
 from the precipices ; but the eastern and almost deserted 
 channel of the Indus, which bounds the province of Cutch, 
 was greatly changed. This estuary, or inlet of the sea, was, 
 before the earthquake, fordable at Luckput, being only about 
 1 foot deep when the tide was at ebb, and at flood tide never 
 more than 6 feet ; but it was deepened at the fort of Luckput, 
 after the shock, to more than 18 feet at low water* On 
 sounding other parts of the channel, it was found, that where 
 previously the depth of the water at flood never exceeded 1 
 or 2 feet, it had become from 4 to 10 feet deep. By these 
 and other remarkable changes of level, a part of the inland 
 navigation of that country, which had been closed for 
 centuries, became again practicable. 
 
 Fort and village submerged. The fort and village of 
 Sindree, on the eastern arm of the Indus, above Luckput, 
 are stated by the same writer to have been overflowed ; and, 
 after the shock, the tops of the houses and wall were alone to 
 be seen above the water, for the houses, although submerged, 
 were not cast down. Had they been situated, therefore, in 
 the interior, where so many forts were levelled to the ground, 
 their site would, perhaps, have been regarded as having 
 remained comparatively unmoved. Hence we may suspect 
 that great permanent upheavings and depressions of soil may 
 be the result of earthquakes, without the inhabitants being 
 in the least degree conscious of any change of level. 
 
 A more recent survey of Cutch, by Sir A. Burnes. who wae 
 not in communication with Captain Macmurdo, confirms the 
 facts above enumerated, and adds many important details. f 
 That officer examined the delta of the Indus in 1826 and 
 1828, and from his account it appears that, when Sindree 
 subsided in June 1819, the sea flowed in by the eastern 
 mouth of the Indus, and in a few hours converted a tract of 
 
 * Macmurdo, Ed. Phil. Journ. iv. 106. brary of the Eoyal Asiatic Society of 
 t Th'.s memoir is now in the Li- London. 
 
 H 2 
 
100 EARTHQUAKES IN THE NINETEENTH CENTURY. [Cn. XXVIII. 
 
 land, 2,000 square miles in area, into an inland sea, or lagoon. 
 Neither the rush of the sea into this new depression, nor the 
 movement of the earthquake, threw down entirely the small 
 fort of Sindree, one of the four towers, the north-western, 
 still continuing to stand ; and, the day after the earthquake, 
 
 106. 
 
 Fort of Sindree, on the eastern branch of the Indus, before it was submerged by 
 the earthquake of 1819, from a sketch of Capt, Grind! ay, made in 1808.* 
 
 the inhabitants, who had ascended to the top of this tower, 
 saved themselves in boats. f 
 
 Elevation of the Ullah Bund. Immediately after the shock, 
 the inhabitants of Sindree saw, at the distance of 5 miles 
 from their village, a long elevated mound, where previously 
 there had been a low and perfectly level plain. (See Map, 
 fig. 105.) To this uplifted tract they gave the name of 'Ullah 
 Bund,' or the c Mound of God,' to distinguish it from several 
 artificial dams previously thrown across the eastern arm of 
 the Indus. 
 
 Extent of country raised. It has been ascertained that this 
 new-raised country is upwards of fifty miles in length from 
 east to west, running parallel to that line of subsidence 
 
 * I was indebted to my friend the late 
 Sir Alexander Burnes for the accom- 
 panying sketch (fig. 106) of the fort of 
 Sindree, as it appeared eleven years 
 before the earthquake. 
 
 t Several particulars not given in 
 the earlier edition were afterwards ob- 
 tained by me from personal com- 
 munication with Sir A. Burnes in 
 London. 
 
CH. XXVIII.] ELEVATION OF THE ULLAII BUND. 101 
 
 before mentioned which caused the grounds around Sindree 
 to be flooded. The range of this elevation extends from 
 Puchum Island towards Gharee ; its breadth from north to 
 south is conjectured to be in some parts sixteen wiles, and its 
 greatest ascertained height above the original level of the 
 delta is 10 feet, an elevation which appears to the eye to 
 be very uniform throughout. 
 
 For several years after the convulsion of 1819, the course 
 of the Indus was very unsettled, and at length, in 1826, the 
 river threw a vast body of water into its eastern arm, that 
 called the Phurraun, above Sindree ; and forcing its way in 
 a more direct course to the sea, burst through all the artificial 
 dams which had been thrown across its channel, and at length 
 cut right through the 'Ullah Bund,' whereby a natural section 
 was obtained. In the perpendicular cliffs thus laid open Sir 
 A. Burnes found that the upraised lands consisted of clay 
 filled with shells. The new channel of the river where it 
 intersected the 'bund' was 18 feet deep, and 40 yards in 
 width ; but in 1828 the channel was still farther enlarged. 
 The Indus, when it first opened this new passage, threw 
 such a body of water into the new mere, or salt lagoon, of 
 Sindree, that it became fresh for many months ; but it had 
 recovered its saltness in 1828, when the supply of river-water 
 was less copious, and finally it became more salt than the sea, 
 in consequence, as the natives suggested to Sir A. Burnes, of 
 the saline particles with which the 6 Eunn of Cutch ' is im- 
 pregnated. 
 
 In 1828 Sir A. Burnes went in a boat to the ruins of 
 Sindree, where a single remaining tower was seen in the 
 midst of a wide expanse of sea. The tops of the ruined 
 walls still rose 2 or 3 feet above the level of the water ; and 
 standing on one of these, he could behold nothing in the 
 horizon but water, except in one direction, where a blue 
 streak of land to the north indicated the Ullah Bund. This 
 scene presents to the imagination a lively picture of the re- 
 volutions now in progress on the earth a waste of waters 
 where a few years before all was land, and the only land 
 visible consisting of ground uplifted by a recent earthquake. 
 
 Ten years after the visit of Sir A. Burnes above alluded to, 
 
102 EARTHQUAKES IN THE NINETEENTH CENTURY. [Cn. XXVIII. 
 
 my friend, Captain Grant, F.G.S., of the Bombay Engineers, 
 had the kindness to send at my request a native surveyor to 
 make a plan of Sindree and Ullah Bund, in March, 1838. 
 From his description it appears that, at that season, the 
 driest of the whole year, he found the channel traversing the 
 Bund to be 100 yards wide, without water, and encrusted 
 with salt. He was told that it has now only 4 or 5 feet of 
 water in it after rains. The sides or banks were nearly 
 perpendicular, and 9 feet in height. The lagoon has 
 diminished both in area and depth, and part near the fort 
 
 Fig. 107. : 
 
 Vievr of the Fort of Sindree, from the west, in March, 1838. 
 
 was dry land. The annexed drawing, made by Captain 
 Grant from the surveyor's plan, shows the appearance of the 
 fort in the midst of the lake, as seen in 1838 from the west 
 or from the same point as that from which Captain Griiidlay's 
 sketch (see fig. 106), was taken in 1808, before the earth- 
 quake. 
 
 The Euiin of Cutch is a flat region of a very peculiar 
 character, and 110 less than 7,000 square miles in area : a 
 greater superficial extent than Yorkshire, or about one- 
 fourth the area of Ireland. It is not a desert of moving 
 sand, nor a marsh, but evidently the dried-up bed of an 
 inland sea, which for a great part of every year has a hard and 
 dry bottom without vegetation or only supporting here and 
 there a few tamarisks. But during the monsoons, when the 
 sea runs high, the salt-water driven up from the Gulf of 
 Cutch and the creeks at Luckput overflows a large part of the 
 Eunn, especially after rains, when the soaked ground permits 
 
Cn. XXVIII.] EFFECTS OF THE EARTHQUAKE OF CUTCH. 103 
 
 the sea-water to spread rapidly. The Emm is also liable to 
 be overflowed occasionally in some parts by river-water : and 
 it is remarkable that the only portion which was ever highly 
 cultivated (that anciently called Sayra) is now permanently 
 submerged. The surface of the Eunn is sometimes encrusted 
 with salt about an inch in depth, in consequence of the 
 evaporation of the sea-water. Islands rise up in some parts 
 of the waste, and the boundary lands form bays and promon- 
 tories. The natives have various traditions respecting the 
 former separation of Cutch and Sinde by a bay of the sea, 
 and the drying up of the district called the Eunn. But these 
 tales, besides the usual uncertainty of oral tradition, are 
 farther obscured by mythological fictions. The conversion 
 of the Eunn into land is chiefly ascribed to the miraculous 
 powers of a Hindoo saint, by name Darnorath (or Dhoorun- 
 nath), who had previously done penance for twelve years on 
 the summit of Denodur hill. Captain Grant infers, on various 
 grounds, that this saint flourished about the llth or 12th 
 century of our era. In. proof of the drying up of the Eunn, 
 some towns far inland are still pointed out as having once 
 been ancient ports. It has, moreover, been always said that 
 ships were wrecked and engulphed by the great catastrophe ; 
 and in the jets of black muddy water thrown out of fissures in 
 that region, in 1819, there were cast up numerous pieces of 
 wrought iron and ship nails.* Cones of sand 6 or 8 feet in 
 height were at the same time formed on these lands. f 
 
 We must not conclude without alluding to a moral phe- 
 nomenon connected with this tremendous catastrophe, which 
 we regard as highly deserving the attention of geologists. It 
 is stated by Sir A. Burnes, that f these wonderful events 
 passed unheeded by the inhabitants of Cutch;' for the region 
 convulsed, though once fertile, had for a long period been 
 reduced to sterility by want of irrigation, so that the natives 
 were indifferent as to its fate. Now it is to this profound 
 apathy which all but highly civilised nations feel, in regard 
 to physical events not having an immediate influence on 
 
 * Capt. Burnes' Account. 
 
 f Capt. Macnuirdo's Memoir, Ed. Phil. Jonrn. vol. iv. p. 106. 
 
104 EARTHQUAKES IN THE NINETEENTH CENTURY. [On. XXVIII. 
 
 their worldly fortunes, that we must ascribe the extraordinary 
 dearth of historical information concerning changes of the 
 earth's surface, which modern observations show to be by no 
 means of rare occurrence in the ordinary course of nature. 
 
 Since the above account was written, a description has 
 been published of more recent geographical changes in the 
 district of Cutch, near the mouth of the Koree, or eastern 
 branch' of the Indus, which happened in June 1845. A large 
 area seems to have subsided, and the Sindreelake had become 
 a salt marsh. * 
 
 Island of Sumbawa, 1815. In April, 1815, one of the most 
 frightful eruptions recorded in history occurred in the province 
 of Tomboro, in the island of Sumbawa (see Map, fig. 59, 
 Yol. I. p. 587), about 200 miles from the eastern extremity 
 of Java. In April of the preceding year the volcano had 
 been observed in a state of considerable activity, ashes having 
 fallen upon the decks of vessels which sailed past the coast, f 
 The eruption of 1815 began on April 5th, but was most 
 violent on the llth and 12th, and did not entirely cease till 
 July. The sound of the explosions was heard in Sumatra, 
 at the distance of 970 geographical miles in a direct line ; 
 and at Ternate, in an opposite direction, at the distance of 
 720 miles. Out of a population of 12,000, in the province of 
 Tomboro, only 26 individuals survived, Violent whirlwinds 
 carried up men, horses, cattle, and whatever else came within 
 their influence, into the air ; tore up the largest trees by the 
 roots, and covered the whole sea with floating timber. J 
 Great tracts of land were covered by lava, several streams of 
 which, issuing from the crater of the Tomboro Mountain, 
 reached the sea. So heavy was the fall of ashes, that they 
 broke into the Resident's house at Bima, 40 miles east of 
 the volcano, and rendered it as well as many other dwellings 
 in the town uninhabitable. On the side of Java the ashes 
 were carried to the distance of 300 miles, and 217 towards 
 Celebes, in sufficient quantity to darken the air. The floating 
 cinders to the westward of Sumbawa formed, on April 12th, 
 
 * Quart. Greol. Journ. vol. ii. p. 103. \ Raffles's Java, vol. i. p. 28. 
 
 f MS. of J. Crawford, Esq. 
 
CH. XXVIII.] EARTHQUAKE IX THE ISLAND OF SLOIEAWA. 105 
 
 a mass 2 feet thick, and several miles in extent, through which 
 ships with difficulty forced their way. 
 
 The darkness occasioned in the daytime by the ashes in 
 Java was so profound, that nothing equal to it was ever 
 witnessed in the darkest night. Although this volcanic dust 
 when it fell was an impalpable powder, it was of consider- 
 able weight when compressed, a pint of it weighing twelve 
 ounces and three quarters. 6 Some -of the finest particles,' 
 says Mr. Crawfurd, 'were transported to the islands of 
 Amboyna and Banda, which last is about 800 miles east 
 from the site of the volcano, although the south-east mon- 
 soon was then at its height.' They must have been projected, 
 therefore, into the upper regions of the atmosphere, where 
 a counter-current prevailed. 
 
 Along the sea-coast of Sumbawa and the adjacent isles, 
 the sea rose suddenly to the height of from 2 to 12 feet, a 
 great wave rushing up the estuaries, and then suddenly 
 subsiding. Although the wind at Binia was still during the 
 whole time, the sea rolled in upon the shore, and filled the 
 lower parts of the houses with water a foot deep. Every 
 prow and boat was forced from the anchorage, and driven 
 on shore. 
 
 The town called Tomboro, on the west side of Sumbawa, 
 was overflowed by the sea, which encroached upon the shore 
 so that the water remained permanently 18 feet deep in 
 places where there was land before. Here we may observe, 
 that the amount of subsidence of land was apparent, in spite 
 of the ashes, which would naturally have caused the limits 
 of the coast to be extended. 
 
 The tremulous noises and other volcanic effects of this 
 eruption extended over an area 1,000 statute miles in 
 diameter, having Sumbawa as its centre. It included the 
 whole of the Molucca Islands, Java, a considerable portion of 
 Celebes, Sumatra, and Borneo, In the island of Amboyna, 
 in the same month and year, the ground opened, threw out 
 water, and then closed again.* 
 
 In conclusion, I may remind the reader, that but for the 
 
 * Raffles's Hist, of Java, vol. i. p. 25. Ed. Phil. Journ. vol. iii. p. 389. 
 
106 EARTHQUAKES IN THE NINETEENTH CENTURY. [Cit. XXVIII. 
 
 accidental presence of Sir Stamford Raffles, then governor of 
 Java, we should scarcely have heard in Europe of this 
 tremendous catastrophe. He required all the residents in 
 the various districts under his authority to send in a state- 
 in ent of the circumstances which occurred within their own 
 knowledge ; but, valuable as were their communications, they 
 are often calculated to excite rather than to satisfy the 
 curiosity of the geologists. They mention, that similar 
 effects, though in a less degree, had, about seven years before, 
 accompanied an eruption of Carang Assam, a volcano in the 
 island of Bali, west of Sumbawa ; but no particulars of that 
 great catastrophe are recorded.* 
 
 Caraccas, 1812. On March 26, 1812, several violent 
 shocks of an earthquake were felt in Caraccas. The surface 
 undulated like a boiling liquid, and terrific sounds were heard 
 underground. ' The whole city with its splendid churches 
 was in an instant a heap of ruins, under which 10,000 of the 
 inhabitants were buried. On April 5, enormous rocks were 
 detached from the mountains. It was believed that the 
 mountain Silla lost from 300 to 360 feet of its height by 
 subsidence; but this was an opinion not founded on any 
 measurement. On April 27, a volcano in St. Vincent's threw 
 out ashes ; and, on the 30th, lava flowed from its crater into 
 the sea, while its explosions were heard at a distance equal 
 to that between Vesuvius and Switzerland, the sound being 
 transmitted, as Humboldt supposes, through the ground. 
 During the earthquake which destroyed Caraccas, an immense 
 quantity of water was thrown out at Yalecillo, near Valencia, 
 as also at Porto Caballo, through openings in the earth; 
 and in the Lake Maracaybo the water sank. Humboldt 
 observed that the Cordilleras, composed of gneiss and mica 
 slate, and the country immediately at their foot, were more 
 violently shaken than the plains. f 
 
 South Carolina and New Madrid, Missouri, 181112. 
 Previous to the destruction of La Guayra and Caraccas, in 
 1812, earthquakes were felt in South Carolina; and the 
 
 * Life and Services of Sir Stamford f Humboldt's Pers.Nar. vol. iv. p. 12; 
 
 Raffles, p. 241. London, 1830. and Ed. Phil. Journ. vol. i. p. 272. 1819. 
 
CH. XXVIII.] EARTHQUAKE IX CARACCAS IX 1812. 107 
 
 shocks continued till those cities were destroyed. The valley 
 also of the Mississippi, from the village of New Madrid 
 to the mouth of the Ohio in one direction, and to the St. 
 Francis in another, was convulsed in such a degree as to 
 create new lakes and islands. It has been remarked by 
 Humboldt in his Cosmos, that the earthquake of New Madrid 
 presents one of the few examples on record of the incessant 
 quaking of the ground for several successive months far from 
 any volcano. Flint, the geographer, who visited the country 
 seven years after the event, informs us, that a tract of many 
 miles in extent, near the Little Prairie, became covered with 
 water 3 or 4 feet deep; and when the water disappeared 
 a stratum of sand was left in its place. Large lakes of 
 20 miles in extent were formed in the course of an hour, 
 and others were drained. The graveyard at New Madrid 
 was precipitated into the bed of the Mississippi; and it is 
 stated that the ground whereon the town is built, and the 
 river bank for 15 miles above, sank 8 feet below their 
 former level.* The neighbouring forest presented for some 
 years afterwards 6 a singular scene of confusion ; the trees 
 standing inclined in every direction, and many having their 
 trunks and branches broken. 'f 
 
 The inhabitants relate that the earth rose in great undu- 
 lations ; and when these reached a certain fearful height, the 
 soil burst, and vast volumes of water, sand, and pit-coal were 
 discharged as high as the tops of the trees. Flint saw 
 hundreds of these deep chasms remaining in an alluvial soil, 
 seven years after. As the shocks lasted throughout a period 
 of three months the country people had time to remark that 
 there were certain prevailing directions in which the fissures 
 opened in their district. Being all of them familiar with the 
 use of the axe, they felled the tallest trees and made them fall 
 at right angles to the direction of the chasms which usually 
 ran from SW. to NE., and by stationing themselves 011 the 
 trees they often escaped being swallowed up when the earth 
 opened beneath them. At one period during this earthquake, 
 
 * Cramer's Navigator, p. 243. Pitts- f Long's Exped. to the Rocky Moun- 
 
 Lurgh, 1821. tains, vol. iii. p. 184. 
 
108 EAKTHQUAKES IN THE NINETEENTH CENTURY. [Cn. XXVIII. 
 
 the ground not far below New Madrid swelled up so as to 
 arrest the Mississippi in its course, and to cause a temporary 
 reflux of its waves. The motion of some of the shocks is 
 described as having been horizontal, and of others perpen- 
 dicular; and the vertical movement is said to have been 
 much less desolating than the horizontal. 
 
 The above account has been reprinted exactly as it 
 appeared in former editions of this work, compiled from the 
 authorities which I have cited; but having more recently 
 (March, 1846) had an opportunity myself of visiting the 
 disturbed region of the Mississippi, and conversing with many 
 eye-witnesses of the catastrophe, I am able to confirm the 
 truth of those statements, and to add some remarks on the 
 present face and features of -the county. I skirted, as was 
 before related (Yol. I. p. 456), part of the territory immediately 
 west of New Madrid, called c the sunk country,' which was 
 for the first time permanently submerged during the earth- 
 quake of 1811-12. It is said to extend along the course of 
 the White Water and its tributaries for a distance of between 
 70 and 80 miles north and south, and 30 miles east and west. 
 I saw on its border many full-grown trees still standing 
 leafless, the bottoms of their trunks several feet under water, 
 and a still greater number lying prostrate. An active vege- 
 tation of aquatic plants is already beginning to fill up some 
 of the shallows, and the sediment washed in by occasional 
 floods when the Mississippi rises to an extraordinary height 
 contributes to convert the borders of the sunk region into 
 marsh and forest land. Even on the dry ground along the 
 confines of the submerged area, I observed in some places 
 that all the trees of prior date to 1811 were dead and leafless, 
 though standing erect and entire. They are supposed to 
 have been killed by the loosening of their roots during the 
 repeated undulations which passed through the ground for 
 three months in succession. 
 
 Mr. Bringier, an experienced engineer of New Orleans, who 
 was on horseback near New Madrid when some of the 
 severest shocks were experienced, related to me (in 1846), 
 that as the waves advanced the trees bent down, and the 
 instant afterwards, while recovering their position, they often 
 
CH. XXVIII.] THOSE OF NEW MADRID, MISSOURI, IN 1811-12. 109 
 
 met those of other trees similarly inclined, so that their 
 branches becoming interlocked, they were prevented from 
 righting themselves again. The transit of the wave through 
 the woods was marked by the crashing noise of countless 
 boughs, first heard on one side and then on the other. At 
 the same time powerful jets of water, mixed with sand, mud, 
 and fragments of coaly matter, were cast up, endangering the 
 lives of both horse and rider.' 
 
 I was curious to ascertain whether any vestiges still 
 remained of these fountains of mud and water, and carefully 
 examined between New Madrid and the Little Prairie several 
 6 sink holes ' as they are termed. They consist of cavities 
 from 10 to 30 yards in width, and 20 feet or more in depth, 
 and are very conspicuous as they interrupt the level surface 
 of a flat alluvial plain. Round their edges I saw abundance 
 of sand, which some of the inhabitants with whom I con- 
 versed had seen spouting from these deep holes, also frag- 
 ments of decayed wood and black bituminous shale, probably 
 drifted down at some former period in the main channel of 
 the Mississippi, from the coal-fields farther north. I also 
 found numerous rents in the soil left by the earthquake, some 
 of them still several feet wide, and a yard or two in depth, 
 although the action of rains, frost, and occasional inunda- 
 tions, and especially the leaves of trees blown into them in 
 countless numbers every autumn, have done much to fill them 
 up. I measured the direction of some of the fissures, which 
 usually varied from 10 to 45 W. of N., and were often 
 parallel to each other; I found, however, a considerable 
 diversity in their direction. Many of them are traceable for 
 half a mile and upwards, but they might easily be mistaken 
 for artificial trenches if resident settlers were not there to 
 assure us that within their recollection they were 6 as deep 
 as wells.' Fragments of coaly shale were strewed along the 
 edges of some of these open fissures, together with white 
 sand, in the same manner as round the ' sink holes. '* 
 
 Among other monuments of the changes wrought in 
 1811-12, I explored the bed of a lake called Eulalie, near 
 
 * See Ly ell's Second Visit to the United States, vol. ii. ch. xxxiii. 
 
110 REFLECTIONS ON EARTHQUAKES OF 19ra CENTURY. [Cn. XXVIII. 
 
 New Madrid, 300 yards long by 100 yards in width, which 
 was suddenly drained during the earthquake. The parallel 
 fissures by which the water escaped were not yet entirely 
 closed, and all the trees growing on its bottom were at the 
 time of my visit less than 34 years old. They consisted of 
 cotton-wood, willows, the honey-locust, and other species, 
 differing from those clothing the surrounding higher 'grounds, 
 which are more elevated by 12 or 15 feet. On them the 
 hiccory, the black and white oak, the gum and other trees, 
 many of them of ancient date, were flourishing. 
 
 Reflections on the earthquakes of the nineteenth century. We 
 are now about to pass on to the events of the eighteenth 
 century : but before we leave the consideration of those 
 already enumerated, let us pause for a moment, and reflect 
 how many remarkable facts of geological interest are afforded 
 by the earthquakes above described, though they constitute 
 but a small part of the convulsions even of half a century. 
 New rocks have risen from the waters ; new hot springs 
 have burst out, and the temperature of others has been 
 altered. A large tract in New Zealand has been upraised 
 from 1 to 9 feet above its former level, and another con- 
 tiguous region depressed several feet, and in the same archi- 
 pelago a fault or displacement of the rocks nearly 100. miles 
 long and about 9 feet in vertical height has been produced. 
 The coast of Chili has been thrice permanently elevated ; a 
 considerable tract in the delta of the Indus has sunk down, 
 and some of its shallow channels have become navigable ; an 
 adjoining part of the same district, upwards of 50 miles in 
 length and 16 in breadth, has been raised about 10 feet above 
 its former level ; part of the great plain of the Mississippi, 
 for a distance of 80 miles in length by 30 in breadth, has 
 sunk down several feet ; the town of Tomboro has been sub- 
 merged, and 12,000 of the inhabitants of Sumbawa have been 
 destroyed. Yet, with a knowledge of these and other terrific 
 catastrophes, witnessed during so brief a period by the 
 present generation, will the geologist declare with perfect 
 composure that the earth has at length settled into a state 
 of repose ? Will he continue to assert that the changes of 
 relative level of land and sea, so common in former ages of 
 
Cr. XXVIII.] REFLECTIONS OX EARTHQUAKES OF 19ra CENTURY. Ill 
 
 the world, have now ceased? If, in the face of so many 
 striking facts, he persists in maintaining this favourite 
 dogma, it is in vain to hope that, by accumulating the proofs 
 of similar convulsions during a series of antecedent ages, we 
 shall shake his tenacity of purpose : 
 
 Si fractus illabatur orbis 
 Impavidum ferient ruinae. 
 
 
112 
 
 CHAPTEE XXIX. 
 
 EARTHQUAKES OF THE EIGHTEENTH CEXTTJRY QUITO, 1797 SICILY, 1790 
 
 CALABRIA, FEBRUARY 5, 1783 SHOCKS CONTINUED TO THE END OF THE YEAR 
 
 1786 AUTHORITIES AREA CONVULSED GEOLOGICAL STRUCTURE OF THE DIS- 
 TRICT MOVEMENT IN THE STONES OF TWO OBELISKS BOUNDING OF DETACHED 
 
 MASSES INTO THE AIR DIFFICULTY OF ASCERTAINING CHANGES OF LEVEL 
 
 SUBSIDENCE OF THE QUAY AT MESSINA SHIFT OR FAULT IN THE ROUND TOWER 
 
 OF TERRANUOVA OPENING AND CLOSING OF FISSURES LARGE EDIFICES EN- 
 
 GULPHED DIMENSIONS OF NEW CAVERNS AND FISSURES GRADUAL CLOSING 
 
 IN OF RENTS DERANGEMENT OF RIVER COURSES LANDSLIPS BUILDINGS 
 
 TRANSPORTED ENTIRE TO GREAT DISTANCES NEW LAKES FUNNEL-SHAPED 
 
 HOLLOWS IN ALLUVIAL PLAINS CURRENTS OF MUD FALL OF CUFFS, AND 
 
 SHORE NEAR SCILLA INUNDATED STATE OF STROMBOLI AND ETNA DURING THE 
 
 SHOCKS ORIGIN AND MODE OF PROPAGATION OF EARTHQUAKE WAVES DEPTH 
 
 OF THE SUBTERRANEAN SOURCE OF THE MOVEMENT NUMBER OF PERSONS 
 
 WHO PERISHED DURING THE EARTHQUAKE OF 1 783 CONCLUDING REMARKS. 
 
 THE earthquakes of the 18th century which we have next 
 to consider are so numerous that a few of them only can 
 be mentioned. I shall select therefore such as are pe- 
 culiarly illustrative of geological changes, treating of the 
 more modern events first, and then of the others in retro- 
 spective order, according to the plan observed in the last 
 chapter for reasons there explained. 
 
 Quito, 1797. The convulsion of this year in Quito was 
 remarkable for the extent of country shaken, and for the 
 alterations caused in river courses, and still more for the 
 floods of ' moya ' or fetid mud which issued from the crater 
 of the volcano of Tunguragua.* 
 
 Caraccas, 1790. During an earthquake in Caraccas in 
 1790 the granitic soil on which the forest of Aripao grew, is 
 said to have sunk, giving rise to a lake 800 yards in diameter, 
 and from 80 to 100 feet in depth. The trees remained 
 green for several months under water. 
 
 * Cavanilles, Journ. de Phys., tome xlix. p. 230. Gilbert's Annalen, bd. vi. 
 Humboldt's Voy. p. 317. 
 
CH. XXIX.] EARTHQUAKES IN SICILY, JAVA, CALABRIA. H3 
 
 Sicily., 1790. Ferrara informs us that in Sicily in the same 
 year (1790) at Santa Maria di Niscemi, some miles from 
 Terranuova, near the south coast, the ground sank down 
 during 7 shocks for a circumference of about 3 miles, and to 
 the depth in one place of 30 feet. The subsidence continued 
 for a month, and several fissures sent forth sulphur, petro- 
 leum, steam and hot water, and a stream of mud flowed out 
 of one of them. The strata where this happened consisted 
 of blue clay, and the site is far distant from the region both 
 of ancient and modern volcanos in Sicily."* 
 
 Java, 1786. During an earthquake in 1786 at Batur in 
 Java which was followed by a volcanic eruption, the river 
 Dotog entered one of several newly-formed rents, and con- 
 tinued after the shocks to pursue a subterranean course. 
 This fact, noticed by contemporary writers, was afterwards 
 verified by Dr. Horsfield. 
 
 EARTHQUAKE OP CALABRIA, 1783. 
 
 Of all the subterranean convulsions of the last century, that 
 of Calabria in 1783 is almost the only one which has been so 
 circumstantially described as materially to aid the geologist 
 in appreciating the changes in the earth's crust which a long 
 repetition of similar events must produce in the lapse of ages. 
 The shocks began in February of that year, and lasted for 
 nearly 4 years, to the end of 1786. Neither in duration, nor 
 in violence, nor in the extent of territory moved, was this 
 convulsion remarkable, when contrasted with many expe- 
 rienced in other countries, both during the last and present 
 century ; nor were the alterations which it occasioned in the 
 relative level of hill and valley, land and sea, so great as those 
 effected by some subterranean movements in South America, 
 in later times. The importance of the earthquake in question 
 arises from the circumstance, that Calabria affords the first 
 example of a region visited, both during and after the convul- 
 sions, by men possessing sufficient leisure, zeal, and scientific 
 information to enable them to collect and describe with accu- 
 racy such physical facts as throw light on geological questions. 
 
 * Ferrara, Cam pi. Flog. p. 51. 
 VOL. II. I 
 
114 EARTHQUAKES IN THE EIGHTEENTH CENTURY. [Cn. XXIX. 
 
 Authorities. Among the numerous authorities, Vivenzio, 
 physician to the King of Naples, transmitted to the court a 
 regular statement of his observations during the continuance 
 of the shocks ; and his narrative is drawn up with care and 
 clearness.* Francesco Antonio Grimaldi, then secretary of 
 war, visited the different provinces at the king's command, 
 and published a most detailed description of the permanent 
 changes in the surface. f He measured the length, breadth, 
 and depth of the different fissures and gulphs which opened, 
 
 Fig. 108. 
 
 17 
 Map of part of Calabria shaken by the earthquake of 1783. 
 
 and ascertained their number in many provinces. His com- 
 ments, moreover, on the reports of the inhabitants, and his 
 explanations of their relations, are judicious and instructive. 
 Pignataro. a physician residing at Monteleone, a town placed 
 in the very centre of the convulsions, kept a register of the 
 
 * Istoria de' Tremuoti della Calabria f Descriz. de' Tremuoti Accad. nelle 
 
 del 1783. Calabria nel 1783. Napoli, 1784. 
 
CH. XXIX.] EARTHQUAKE OF CALABRIA, 1783. 115 
 
 shocks, distinguishing* them into four classes, according to 
 their degree of violence. From his work, it appears that, in 
 the year 1783, the number was 949, of which 501 were 
 shocks of the first degree of force ; and in the following year 
 there were 151, of which 98 were of the first magnitude. 
 
 Count Ippolito, also, and many others, wrote descriptions 
 of the earthquake ; and the Royal Academy of Naples, not 
 satisfied with these and other observations, sent a deputation 
 from their own body into Calabria, before the shocks had 
 ceased, who were accompanied by artists instructed to illus- 
 trate by drawings the physical changes of the district, and 
 the state of ruined towns and edifices. Unfortunately these 
 artists were not very successful in their representations of 
 the condition of the country, particularly when they attempted 
 to express, on a large scale, the extraordinary revolutions 
 which many of the great and minor river-courses underwent. 
 But some of the plates published by the Academy are valu- 
 able ; and as they are little known, I shall frequently avail 
 myself of them to illustrate the facts about to be described.* 
 
 In addition to these Neapolitan sources of information, 
 our countryman, Sir William Hamilton, surveyed the district, 
 not without some personal risk, before the shocks had 
 ceased; and his sketch, published in the Philosophical 
 Transactions, supplies many facts that would otherwise have 
 been lost. He has explained, in a rational manner, many 
 events which, as related in the language of some eye-wit- 
 nesses, appeared marvellous and incredible. Dolomieu also 
 examined Calabria during the catastrophe, and wrote an 
 account of the earthquake, correcting a mistake into which 
 Hamilton had fallen, who supposed that a part of the tract 
 shaken had consisted of volcanic tuff. It is, indeed, a cir- 
 cumstance which enhances the geological interest of the 
 commotions which so often modify the surface of Calabria, 
 that they are confined to a country where there are neither 
 ancient nor modern rocks of volcanic or trappean origin; 
 so that at some future time, when the era of disturbance 
 shall have passed by, the cause of former revolutions will be 
 
 * Istoria de' Fenomeni del Tremoto, Real. Accad. &c. di Nap. Napoli, 
 &c. nell' An. 1783, posta in luce dalla 1783, fol. 
 
 I 2 
 
116 EARTHQUAKES IN THE EIGHTEENTH CENTURY. [Cn. XXIX. 
 
 as latent as in parts of Great Britain now occupied exclusively 
 by ancient marine formations. 
 
 Extent of the area convulsed. The convulsion of the earth, 
 sea, and air extended over the whole of Calabria Ultra, the 
 south-east part of Calabria Citra, and across the sea to 
 Messina and its environs ; a district lying between the 38th 
 and 39th degrees of latitude. The concussion was percep- 
 tible over a great part of Sicily, and as far north as Naples ; 
 but the surface over which the shocks acted so forcibly as to 
 excite intense alarm did not generally exceed 500 square 
 miles in area. That part of Calabria is composed chiefly, 
 like the southern part of Sicily, of argillaceous strata of great 
 thickness, containing marine shells, sometimes associated 
 with beds of sand and limestone. For the most part these 
 formations resemble in appearance and consistency the Sub- 
 apennine marls, with their accompanying sands and sand- 
 stones ; and the whole group bears considerable resemblance, 
 in the yielding nature of its materials, to most of our tertiary 
 deposits in France and England. Chronologically considered, 
 however, the Calabrian formations are comparatively of 
 modern date, often abounding in fossil shells referable to 
 species now living in the Mediterranean. 
 
 We learn from Yivenzio, that on the 20th and 26th of 
 March, 1783, earthquakes occurred in the islands of Zante, 
 Cephalonia, and St. Maura; and in the last-mentioned island 
 several public edifices and private houses were overthrown, 
 and many people destroyed. 
 
 If the city of Oppido, in Calabria Ultra, be taken as a 
 centre, and round that centre a circle be described, with a 
 radius of 22 miles, this space will comprehend the surface 
 of the country which suffered the greatest alteration, and 
 where all the towns and villages were destroyed. The first 
 shock, of February 5, 1783, threw down, in two minutes, the 
 greater part of the houses in all the cities, towns, and villages, 
 from the western flanks of the Apennines in Calabria Ultra 
 to Messina in Sicily, and convulsed the whole surface of the 
 country. Another occurred on March 28, with almost equal 
 violence. The granitic chain which passes through Calabria 
 from north to south, and attains the height of many thousand 
 
CH. XXIX.] EFFECTS OF CALABRIAN EARTHQUAKE. 117 
 
 feet, was shaken but slightly by the first shock, but more 
 rudely by some which followed. 
 
 Some writers have asserted that the wave-like movements 
 which were propagated through the recent strata, from west 
 to east, became very violent when they reached the point of 
 junction with the granite, as if a reaction was produced 
 where the undulatory movement of the soft strata was 
 suddenly arrested by the more solid rocks. But the state- 
 ment of Dolomieu on this subject is most interesting, and 
 perhaps, in a geological point of view, the most important 
 of all the observations which are recorded.* The Apennines, 
 he says, which consist in great part of hard and solid granite, 
 with some micaceous and argillaceous schists, form bare 
 mountains with steep sides, and exhibit marks of great 
 degradation. At their base newer strata are seen of sand 
 and clay, mingled with shells ; a marine deposit containing 
 such ingredients as would result from the decomposition of 
 granite. The surface of this newer (tertiary) formation con- 
 stitutes what is called the plain of Calabria a platform 
 which is flat and level, except where intersected by narrow 
 valleys or ravines, which rivers and torrents have excavated 
 sometimes to the depth of 600 feet. The sides of these 
 ravines are almost perpendicular ; for the superior stratum, 
 being bound together by the roots of trees, prevents the 
 formation of a sloping bank. The usual effect of the earth- 
 quake, he continues, was to disconnect all those masses 
 which either had not sufficient bases for their bulk, or which 
 were supported only by lateral adherence. Hence it follows 
 that throughout the whole length of the chain, the soil 
 which adhered to the granite at the base of the mountains 
 Caulone, Esope, Sagra, and Aspramonte, slid over the solid 
 and steeply inclined nucleus, and descended somewhat 
 lower, leaving almost uninterruptedly from St. George to 
 beyond St. Christina, a distance of from 9 to 10 miles, a 
 chasm between the solid granitic nucleus and the sandy 
 soil. Many lands slipping thus were carried to a considerable 
 distance from their former position, so as entirely to cover 
 
 * Dissertation on the CalaLrian Earthquake, &c., translated in Pinkertou's 
 Voyages and Travels, vol. v. 
 
118 EARTHQUAKES IN THE EIGHTEENTH CENTURY. [CH. XXIX. 
 
 others ; and disputes arose as to whom the property which 
 had thus shifted its place should belong. 
 
 From this account of Dolomieu we might anticipate, as 
 the result of a continuance of such earthquakes, first, a 
 longitudinal valley following the line of junction of the older 
 and newer rocks ; secondly, greater disturbance in the newer 
 strata near the point of contact than at a greater distance 
 from the mountains ; phenomena very common in other 
 parts of Italy at the junction of the Apennine and Sub- 
 apennine formations. 
 
 Mr. Mallet, in his valuable essay on the Dynamics of 
 Earthquakes,* offers the following explanation of the fact to 
 which Dolomieu has called attention. When a wave of 
 elastic compression, of which he considers the earth -wave to 
 consist, passes abruptly from a body having an extremely 
 low elasticity, such as clay and gravel, into another like 
 granite, whose elasticity is remarkably high, it changes not 
 only its velocity but in part also its course, a portion being 
 reflected and a portion refracted. The wave being thus sent 
 back again produces a shock in the opposite direction, doing 
 great damage to buildings on the surface by thus returning 
 upon itself. At the same time, the shocks are at once eased 
 when they get into the more elastic materials of the granitic 
 mountains. 
 
 The surface of the country during the Calabriaii earth- 
 quakes often heaved like the billows of a swelling sea, which 
 produced a swimming in the head, like sea-sickness. It is 
 particularly stated, in almost all the accounts, that just 
 before each shock the clouds appeared motionless ; and, 
 although no explanation is offered of this phenomenon, it 
 seems obviously the same as that observed in a ship at sea 
 when it pitches violently. The clouds seem arrested in their 
 career as often as the vessel rises in a direction contrary to 
 their course ; so that the Calabrians must have experienced 
 precisely the same motion on the land. 
 
 Trees, supported by their trunks, sometimes bent during 
 the shocks to the earth, and touched it with their tops. This 
 
 * Proceed. Roy. Irish Acad. 1846, p. 26. 
 
CH. XXIX.] EFFECTS OF CALABRIAN EARTHQUAKE. 119 
 
 is mentioned as a well-known fact by Dolomieu; and lie 
 assures us that he was always on his guard against the spirit 
 of exaggeration in which the vulgar are ever ready to indulge 
 when relating these wonderful occurrences. 
 
 The reader must not suppose that these waves, although 
 described as passing along the solid surface of the earth in a 
 given direction like a billow on the sea, have any strict 
 analogy with the undulations of a fluid. They must be 
 regarded as the effects of vibrations, radiating from some 
 deep-seated point, each vibration on reaching the surface 
 lifting up the ground, and then allowing it again to subside. 
 The manner in which the vibratory jar reaches different 
 points of the surface in succession according to the outline 
 of the country, will be explained in the sequel, see p. 136. 
 
 Shifts in the stones of two obelisks in the Convent of S. Bruno. 
 
 The Academicians relate that in some of the cities of 
 Calabria effects were produced seeming to indicate a whirling 
 or vorticose movement. Thus, for example, two obelisks 
 (fig. 109) placed at the extremities of a magnificent fa9ade in 
 the convent of S. Bruno, in a small town called Stefano del 
 Bosco, were observed to have undergone a movement of a 
 singular kind. The shock which agitated the building is de- 
 scribed as having been horizontal and vorticose. The pedestal 
 of each obelisk remained in its original place ; but the sepa- 
 rate stones above were turned partially round, and removed 
 sometimes nine inches from their position without falling. 
 
120 EARTHQUAKES IN THE EIGHTEENTH CENTURY. [Cn. XXIX. 
 
 It has been suggested by Mr. Darwin, that this kind of 
 displacement may be due to a vibratory rather than a whirling 
 motion ;* and more lately Mr. Mallet, in the paper already 
 cited, has offered a very ingenious solution of the problem. 
 He refers the twisting simply to an elastic wave, which has 
 moved the pedestal forwards and back again, by an alternate 
 horizontal motion within narrow limits ; and he has succeeded 
 in showing that a rectilinear movement in the ground may 
 have sufficed to cause an incumbent body to turn partially 
 round upon its bed, provided a certain relation exist between 
 the position of the centre of gravity of the body and its centre 
 of adherence. f 
 
 The violence of the movement of the ground upwards was 
 singularly illustrated by what the Academicians call the 
 f sbalzo,' or bounding into the air, to the height of several yards, 
 of masses slightly adhering to the surface. In some towns 
 a great part of the pavement stones were thrown up, and found 
 lying with their lower sides uppermost, In these cases, we 
 must suppose that they were propelled upwards by the mo- 
 mentum which they had acquired ; and that the adhesion of 
 one end of the mass being greater than that of the other, a 
 rotatory motion had been communicated to them. When the 
 stone was projected to a sufficient height to perform somewhat 
 more than a quarter of a revolution in the air, it pitched 
 down on its edge, and fell with its lower side uppermost. 
 
 New fissures and changes of level. I shall now consider, in 
 the first place, those changes which are connected with the 
 rending and fissuring of rocks or with alterations in the 
 relative level of the different parts of the land ; and afterwards 
 describe those which are more immediately connected with 
 the derangement of the regular drainage of the country, and 
 where the force of running water cooperated with that of 
 the earthquake. 
 
 In regard to alterations of relative level, none of the 
 accounts establish that they were on a considerable scale ; 
 but it must always be remembered that, in proportion to the 
 area moved is the difficulty of proving that the general level 
 
 * Journal of a Naturalist, p. 376, f Proceedings Roy. Irish Acad. 1846, 
 
 and ii. ib. 308. pp. 14-16. 
 
CH. XXIX.] EFFECTS OF CALABRIAN EARTHQUAKE. 121 
 
 has undergone any change, unless the sea-coast happens to 
 have participated in the principal movement. Even then it 
 is often impossible to determine whether an elevation or de- 
 pression even of several feet has occurred, because there is 
 nothing to attract notice in a band of shingle and sand of un- 
 equal breadth above the level of the sea running parallel to 
 a coast ; such bands generally marking the point reached by 
 the waves during spring tides, or the most violent tempests. 
 The scientific investigator has not sufficient topographical 
 knowledge to discover whether the extent of beach has di- 
 minished or increased ; and he who has the necessary local 
 information scarcely ever feels any interest in ascertaining 
 the amount of the rise or fall of the ground. Add to this the 
 great difficulty of making correct observations, in consequence 
 of the enormous waves which roll in upon a coast during an 
 earthquake, and efface every landmark near the shore. 
 
 It is evidently in seaports alone that we can look for very 
 accurate indications of slight changes of level ; and when we 
 find them, we may presume that they would not be rare at 
 other points, if equal facilities of comparing relative altitudes 
 were afforded. Grimaldi states (and his account is confirmed 
 by Hamilton and others), that at Messina, in Sicily, the shore 
 was rent ; and the soil along the port, which before the shock 
 was perfectly level, was found afterwards to be inclined to- 
 wards the sea, the sea itself near the c Branchia ' becoming 
 deeper, and its bottom in several places disordered. The 
 quay also sunk down about 14 inches below the level of the 
 sea, and the houses in its vicinity were much fissured.* 
 
 Unfortunately we are without data for determining whether 
 these changes were superficial only, and due to the sliding 
 down or settling of the soil, or whether they were connected 
 with deep-seated movements altering the relative level of sea 
 and land. 
 
 Among various proofs of partial elevation and depression 
 in the interior, the Academicians mention, in their Survey, 
 that the ground was sometimes on the same level on both 
 sides of new ravines and fissures, but sometimes there had 
 
 * Phil. Trans. 1783. 
 
122 EARTHQUAKES IN THE EIGHTEENTH CENTUKY. [On. XXIX. 
 
 been a considerable upheaving of one side, or subsidence of 
 the other. Thus, on the sides of long rents in the territory 
 of Soriano, the stratified masses had altered their relative 
 position to the extent of from 8 to 14 palms (6 to 10^ feet). 
 
 Similar shifts in the strata are alluded to in the territory 
 of Polistena, where there appeared innumerable fissures in 
 the earth. One of these was of great length and depth ; and 
 in parts the level of the corresponding sides was greatly 
 changed. (See fig. 110.) 
 
 In the town of Terranuova some houses were seen uplifted 
 a,bove the common level, and others adjoining sunk down 
 into the earth. In several streets the soil appeared thrust 
 
 Deep fissure, near Polistena, caused by the earthquake of 1782. 
 
 up, and abutted against the walls of houses : a large circular 
 tower of solid masonry, part of which had withstood the 
 general destruction, was divided by a vertical rent, and one 
 side was upraised, and the foundations heaved out of the 
 ground. It was compared by the Academicians to a great 
 tooth half extracted from the alveolus, with the upper part 
 of the fangs exposed. (See fig. 111.) 
 
 Along the line of this shift, or c fault,' as it would be termed 
 technically by miners, the walls were found to adhere firmly 
 to each other, and to fit so well, that the only signs of their 
 having been disunited was the want of correspondence in the 
 courses of stone on either side of the rent. 
 
On. XXIX.] EFFECTS OF CALABRIAX EARTHQUAKE. !;;} 
 
 Dolomieu saw a stone well in the convent of the Augustins 
 at Terranuova, which had the appearance of having been 
 driven out of the earth. It resembled a small tower 8 or 9 
 feet in height, and a little inclined. This effect, he says, 
 was produced by the consolidation and consequent sinking of 
 the sandy soil in which the well was dug. 
 
 In some walls which had been thrown down, or violently 
 shaken, in Moiiteleoiie, the separate stones were parted from 
 the mortar, so as to leave an exact mould where they had 
 rested ; whereas in other cases the mortar was erround to 
 
 o 
 
 dast between the stones. 
 
 . 111. 
 
 Shift or ' fault' in the Round Tower of Terranuova in Calabria, occasioned by the 
 earthquake of 1783. 
 
 It appears that the wave-like motions often produced 
 effects of the most capricious kind. Thus, in some streets of 
 Moiiteleoiie, every house was thrown down but one ; in 
 others, all but two ; and the buildings which were spared 
 were often scarcely in the least degree injured. In many 
 cities of Calabria, all the most solid buildings were thrown 
 down, while those which were slightly built escaped; but at 
 Rosarno, as also at Messina in Sicily, it was precisely the 
 reverse, the massive edifices being the only ones that stood. 
 
 As the earthquake-wave passed along the surface of the 
 ground, rents and chasms opened and closed alternately, so 
 
124 EARTHQUAKES IN THE EIGHTEENTH CENTUEY. [Cn. XXIX. 
 
 that houses, trees, cattle and men were first engulphed in an 
 instant, and then the sides of the fissures coming together 
 again no vestige of them was to be seen on the surface. We 
 may conceive the same effect to be produced on a small scale, 
 if, by some mechanical force, a pavement composed of large 
 flags of stone should be raised up, and then allowed to fall 
 suddenly, so as to resume its original position. If any small 
 pebbles happened to be lying on the line of contact of two 
 flags, they would fall into the opening when the pavement 
 rose, and be swallowed up, so that no trace of them would 
 appear after the subsidence of the stones. In many instances, 
 .individuals are said to have been swallowed up by one shock, 
 
 Pig. 112. 
 
 Fissures near Jeroearne, in Calabria, caused by the earthquake of 1783. 
 
 and then thrown out again alive, together with large jets of 
 water, by the shock which immediately succeeded. 
 
 At Jerocarne, a country which, according to the Academi- 
 cians, was lacerated in a most extraordinary manner, the 
 fissures ran in every direction ' like cracks on a broken pane 
 of glass.' (See fig. 112,) 
 
 As we learn from Dolomieu that the direction of the new 
 chasms and fissures throughout Calabria was usually parallel 
 to the course of ravines and gorges pre-existing in their 
 neighbourhood, we may conclude that not a few of them 
 were due to a comparatively superficial movement of the 
 ground in a sideway direction. 
 
Cn. XXIX.] EFFECTS OF CALABRIAN EARTHQUAKE. 125 
 
 In the vicinity of Oppido, the central point where the 
 shocks of the earthquake were most violent, many houses 
 were swallowed up by the yawning earth, which closed 
 ini mediately over them. In the adjacent district, also, of 
 Caiinamaria four farm-houses, several oil-stores, and some 
 spacious dwelling-houses were so completely engulphed in 
 one chasm, that not a vestige of them was afterwards dis- 
 cernible. The same phenomenon occurred at Terraiiuova, 
 S. Christina, and Sinopoli. The Academicians state parti- 
 cularly, that when deep abysses had opened in the argillaceous 
 strata of Terranuova, and houses had sunk into them, the 
 sides of the chasms closed with such violence, that, on 
 excavating afterwards to recover articles of value, the work- 
 men found the contents and detached parts of the buildings 
 jammed together so as to become one compact mass. 
 
 Sir W. Hamilton was shown several deep fissures in the 
 vicinity of Mileto, which, although not one of them was 
 above a foot in breadth, had opened so wide during the 
 earthquake as to swallow an ox and nearly one hundred 
 goats. The Academicians also found, on their return through 
 districts which they had passed at the commencement of 
 their tour, that many rents had, in that short interval, 
 gradually closed in, so that their width had diminished 
 several feet, and the opposite walls had sometimes nearly 
 met. It is natural that this should happen in argillaceous 
 strata, while, in more solid rocks, we may expect that fissures 
 will remain open for ages. Should this be ascertained to be 
 a general fact in countries convulsed by earthquakes, it may 
 afford a satisfactory explanation of a common phenomenon in 
 mineral veins. Such veins often retain their full size so long 
 as the rocks consist of limestone, granite, or other indurated 
 materials ; but they contract their dimensions, become mere 
 threads, or are even entirely cut off, where masses of an 
 argillaceous nature are interposed. If we suppose the 
 filling up of fissures with metallic and other ingredients to 
 be a process requiring ages for its completion, it is obvious 
 that the opposite walls of rents, where strata consist of 
 yielding materials, must collapse or approach very near to 
 each other before sufficient time is allowed for the accretion 
 of a large quantity of veinstone. 
 
126 EAKTHQUAKES IX THE EIGHTEENTH CENTUEY. [Cn. XXIX. 
 
 Some of the chasms which opened seem to imply the 
 sinking down of the earth into subterranean cavities. One 
 of these was observed by the Academicians on the sloping 
 
 Fig. 113. 
 
 Chasm formed by the earthquake or 1783 near Oppido, in Calabria. 
 
 side of a hill near Oppido, into which part of a vineyard and 
 a considerable number of olive trees with a large quantity of 
 soil were precipitated. Yet a great gulf remained after the 
 
 Fig. 114. 
 
 Chasm in the hill of St. Angelo, near Soriano, in Calabria, caused by the earth- 
 quake of 1783. 
 
 shock, in the form of an amphitheatre, 500 feet long and 200 
 feet deep. (See fig. 113.) 
 
 According to Grimaldi, many fissures and chasms, formed 
 
CH. XXIX.] EFFECTS OF CALABRIAN EARTHQUAKE. 127 
 
 by the first shock of February 5th, were greatly widened, 
 lengthened, and deepened by the violent convulsions of 
 March 28th. Some of these were nearly a mile in length, 
 and from 150 to more than 200 feet in depth, usually 
 straight but some of them in the form of a crescent. The 
 annexed cut (fig. 114) represents one by no means remarkable 
 for its dimensions, which remained open by the side of a 
 small pass over the hill of St. Angelo, near Soriana. The 
 small river Mesima is seen in the foreground. 
 
 Formation of circular hollows and new lakes. In the report 
 of the Academy, we find that some plains were covered with 
 
 Circular hollows in the plain of Rosarno, formed by the earthquake of 1783. 
 
 circular hollows, for the most part about the size of carriage- 
 wheels, but often somewhat larger or smaller. When filled 
 with water to within a foot or two of the surface, they 
 appeared like wells ; but, in general, they were filled with 
 dry sand, sometimes with a concave surface, and at other 
 times convex. (See fig. 115.) On digging down, they found 
 them to be funnel-shaped, and the moist loose sand in the 
 centre marked the tube up which the water spouted. The 
 annexed cut (fig. 116) represents a section of one of these 
 inverted cones when the water had disappeared, and nothing 
 but dry micaceous sand remained. 
 
128 EARTHQUAKES IN THE EIGHTEENTH CENTURY. [Cn. XXIX. 
 
 A small circular pond of similar character was formed not 
 far from Polistena (see fig. 117); and in the vicinity of 
 Seminara, a lake was suddenly caused by the opening of a 
 great chasm, from the bottom of which water issued. This 
 
 Fig. 116. 
 
 Section of one of the circular hollows formed in the plain of Rosarno. 
 
 lake was called Lago del Tolfilo. It extended 1,785 feet in 
 length, by 937 in breadth, and 52 in depth. The inhabitants, 
 dreading the miasma of this stagnant pool, endeavoured, at 
 
 Fig. 117. 
 
 Circular pond near Polistena in Calabria, caused by the earthquake in 1783. 
 
 great cost, to drain it by canals, but without success, as it 
 was fed by springs issuing from the bottom of the deep 
 chasm. 
 
 Cones of sand thrown up. Many of the appearances ex- 
 hibited in the alluvial plains, such as springs spouting up 
 their water like fountains at the moment of the shock, have 
 been supposed to indicate the alternate rising and sinking of 
 
CH. XXIX.] DERANGEMENT OF RIVEE-COUESES. 120 
 
 the ground. The first effect of the more violent shocks was 
 usually to dry up the rivers, but they immediately afterwards 
 overflowed their banks. In marshy places, an immense 
 number of cones of sand were thrown up. These appearances 
 Hamilton explains, by supposing that the first movement 
 raised the fissured plain from below upwards, so that the 
 rivers and stagnant waters in bogs sank down, or at least 
 were not upraised with the soil. But when the ground 
 returned with violence to its former position, the water was 
 thrown up in jets through fissures. 
 
 The phenomenon, according to Mr. Mallet, may be simply 
 an accident contingent on the principal cause of disturbance, 
 the rapid transit of the earth-wave. ' The sources,' he says, 
 4 of copious springs usually lie in flat plates or fissures filled 
 with water, whether issuing from solid rock, or from loose 
 materials ; now, if a vein, or thin flat cavity filled with 
 water, be in such a position that the plane of the plate of 
 water or fissure be transverse to the line of transit of the 
 earth-wave, the effect of the arrival of the earth-wave at the 
 watery fissure will be, at the instant, to compress its walls 
 more or less together, and so squeeze out the water, which 
 will, for a moment, gush up at the springhead like a fountain, 
 and again remain in repose after the transit of the wave.' 
 
 Derangement of river-courses. Vivenzio states, that near 
 Sitizzano a valley was nearly filled up to a level with the 
 high grounds on each side, by the enormous masses detached 
 from the boundary hills, and cast down into the course of two 
 streams. By this barrier a lake was formed of great depth, 
 about 2 miles long and 1 mile broad. The same author 
 mentions that, upon the whole, there were 50 lakes occasioned 
 during the convulsions : and he assigns localities to all of 
 these. The government surveyors enumerated 215 lakes ; 
 but they included in this number many small ponds. 
 
 Such lakes and ponds could only be permanent where rivers 
 and brooks were diverted into an entirely new course, whether 
 into some adjoining ravine or into a different part of the 
 same alluvial plain. In cases where the new barrier obstructs 
 the whole of the drainage, the water flowing over the dam 
 
 VOL. II. K 
 
130 EARTHQUAKES IN THE EIGHTEENTH CENTURY. [Cn. XXIX. 
 
 will gradually deepen a new channel in it, and the lake will 
 exist no longer.* 
 
 From each side of the deep valley or ravine of Terranuova, 
 enormous masses of the adjoining flat country were detached, 
 and cast down into the course of the river, so as to give rise 
 to lakes. Oaks, olive-trees, vineyards, and corn, were often 
 seen growing at the bottom of the ravine, as little injured as 
 their former companions, which still continued to flourish in 
 the plain above, at least 500 feet higher, and at the distance 
 of about | of a mile. In one part of this ravine was a mass, 
 200 feet high and about 400 feet at its base, which had been 
 detached by some former earthquake. It is well attested, 
 that this mass travelled down the ravine nearly 4 miles, 
 having been put in motion by the earthquake of February 5. 
 Hamilton, after examining the spot, declared that this phe- 
 nomenon might be accounted for by the declivity of the 
 valley, the great abundance of rain which fell, and the great 
 weight of the alluvial matter which pressed behind it. 
 Dolornieu also alludes to the fresh impulse derived from 
 other masses falling, and pressing upon the rear of those 
 first set in motion. 
 
 The first account sent to Naples of the two great slides or 
 landslips above alluded to, which caused a great lake near 
 Terranuova, was couched in these words : ( Two mountains 
 on the opposite sides of a valley walked from their original 
 position until they met in the middle of the plain, and there 
 joining together, they intercepted the course of a river,' &c. 
 The expressions here used resemble singularly those applied 
 to phenomena, probably very analogous, which are said to 
 have occurred at Fez, during the great Lisbon earthquake, 
 as also in Jamaica and Java at other periods. 
 
 Not far from Soriano, the houses of which were levelled to 
 the ground by the great shock of February, a small valley, 
 containing a beautiful olive-grove, called Fra Eamondo, 
 underwent a most extraordinary revolution. Innumerable 
 fissures first traversed the river-plain in all directions, and 
 absorbed the water until the argillaceous substratum became 
 
 * See Robert Mullet, Neapolitan Earthquake of 1857, vol. ii. p. 372. 
 
CH. XXIX.] LANDSLIPS NEAR SORIANO. 131 
 
 soaked, so that a great part of it was reduced to a state of 
 fluid paste. Strange alterations in the outline of the ground 
 were the consequence, as the soil to a great depth was easily 
 moulded into any form. In addition to this change, the 
 ruins of the neighbouring hills were precipitated into the 
 hollow; and while many olives were uprooted, others re- 
 mained growing on the fallen masses, and inclined at various 
 angles. (See fig. 118.) The small river Caridi was entirely 
 concealed for many days ; and when at length it reappeared, 
 it had shaped for itself a new channel. 
 
 Near Seminara an extensive olive-ground and orchard were 
 
 Fig. 118 
 
 Changes of the surface at Fra Ramondo, near Soriano, in Calabria. 
 
 1 . Portion of a hill covered with olives 2. New bed of the river Caridi. 
 
 thrown down. 3. Town of Soriano. 
 
 hurled to a distance of 200 feet, into a valley 60 feet in depth. 
 At the same time a deep chasm was riven in another part of 
 the high platform from which the orchard had been detached, 
 and the river immediately entered the fissure, leaving its 
 former bed completely dry. A small inhabited house, stand- 
 ing on the mass of earth carried down into the valley, went 
 along with it entire, and without injury to the inhabitants. 
 The olive-trees, also, continued to grow on the land which 
 had slid into the valley, and bore the same year an abundant 
 crop of fruit. 
 
 K 2 
 
132 EARTHQUAKES IN THE EIGHTEENTH CENTURY. CH. XXIX. 
 
 Two tracts of land on which a great part of the town of 
 Polistena stood, consisting of some hundreds of houses, were 
 detached into a contiguous ravine, and nearly across it, about 
 half a mile from their original site ; and what is most extra- 
 ordinary, several of the inhabitants were dug out from the 
 ruins alive and unhurt. 
 
 Two tenements, near Mileto, called the Macini and Yati- 
 cano, occupying an extent of ground about 1 mile long and J 
 a mile broad, were carried for 1 mile down a valley. A 
 thatched cottage, together with large olive and mulberry 
 trees, most of which remained erect, were carried uninjured 
 to this extraordinary distance. According to Hamilton, the 
 surface removed had been long undermined by rivulets, which 
 
 Fig- 119. 
 
 Landslips near Cinquefrondi, caused Ly the earthquake of 1783. 
 
 were afterwards in full view on the bare spot deserted by the 
 tenements. The earthquake seems to have opened a passage 
 in the adjoining argillaceous hills, which admitted water 
 charged with loose soil into the subterranean channels of 
 the rivulets immediately under the tenements, so that the 
 foundations of the ground set in motion by the earthquake 
 were loosened. Another example of subsidence, where the 
 edifices were not destroyed, is mentioned by Grimaldi, as 
 having taken place in the city of Catanzaro, the capital of 
 the province of that name. The houses in the quarter called 
 San Giuseppe subsided with the ground to various depths 
 
CH. XXIX.] LANDSLIPS NEAR S. LUCIDO. 133 
 
 from 2 to 4 feet, but the buildings remained uninjured. 
 Among other territories, that of Cinquefrondi was greatly 
 convulsed, various portions of soil being raised or sunk, and 
 innumerable fissures traversing the country in all directions 
 (see fig. 119). Along the flanks of a small valley in this 
 district there appears to have been an almost uninterrupted 
 line of landslips. 
 
 Near S. Lucido, among other places, the soil is described 
 as having been c dissolved,' so that large torrents of mud 
 inundated all the low grounds, like lava. Just emerging 
 from this mud, the tops only of trees and of the ruins of 
 farm-houses were seen. Two miles from Laureana, the 
 swampy soil in two ravines became filled with calcareous 
 matter, which oozed out from the ground immediately before 
 the first great shock. This mud, rapidly accumulating, began, 
 ere long, to roll onward, like a flood of lava, into the valley, 
 where the two streams uniting, moved forward with increased 
 impetus from east to west. It now presented a breadth of 
 225 feet by 15 in depth, and, before it ceased to move, 
 covered a surface equal in length to an Italian mile. In its 
 progress it overwhelmed a flock of 30 goats, and tore up by 
 the roots many olive and mulberry trees, which floated like 
 ships upon its surface. When this calcareous lava had 
 ceased to move, it gradually became dry and hard, during 
 which process the mass was lowered 7J feet. It contained 
 fragments of earth of a ferruginous colour, and emitting a 
 sulphureous smell. 
 
 If our space permitted, we might fill a volume with local 
 details of landslips, which the different authors above alluded 
 to, supply, showing to how great an extent the power of rivers 
 to widen valleys is increased where earthquakes are of 
 periodical occurrence. A geologist can never fully under- 
 stand the manner in which valleys have been formed until 
 he duly appreciates the part which subterranean movements 
 repeated at long intervals play in combination with rivers, 
 during that lapse of ages which must always be required for 
 the elevation of a country to the height of many hundreds 
 of feet above the level of the sea. 
 
 Time must be allowed in the intervals between distinc- 
 
134 EARTHQUAKES IN THE EIGHTEENTH CENTURY. [Cn. XXIX. 
 
 convulsions, for running* water to clear away the ruins 
 caused by landslips, otherwise the fallen masses will serve 
 as buttresses, and prevent the succeeding earthquake from 
 exerting its full power. The sides of the valley must be 
 again cut away by the stream, and made to form precipices 
 and overhanging cliffs, before the next shock can take effect 
 in the same manner. 
 
 Fall of the sea-cliffs. Along the sea-coast of the Straits of 
 Messina, near the celebrated rock of Scilla, the fall of huge 
 masses detached from the bold and lofty cliffs overwhelmed 
 many villas and gardens. At Gian Greco, a continuous line 
 of cliff, for a mile in length, was thrown down. Great 
 agitation was frequently observed in the bed of the sea 
 during the shocks, and, on those parts of the coast where the 
 movement was most violent, all kinds of fish were taken in 
 abundance, and with unusual facility. Some rare species, as 
 that called Cicirelli, which usually lie buried in the sand, 
 were taken on the surface of the waters in great quantity. 
 The sea is said to have boiled up near Messina and to have 
 been agitated as if by a copious discharge of vapours from 
 its bottom. 
 
 Shore near Scilla inundated. The prince of Scilla had 
 persuaded a great part of his vassals to betake themselves to 
 their fishing-boats for safety, and he himself had gone on 
 board. On the night of February 5, when some of the people 
 were sleeping in the boats, and others on a level plain slightly 
 elevated above the sea, the earth rocked, and suddenly a 
 great mass was torn from the contiguous Mount Jaci, and 
 thrown down with a dreadful crash upon the plain. Im- 
 mediately afterwards, the sea, rising more than 20 feet 
 above the level of this low tract, rolled foaming over it, and 
 swept away the multitude. It then retreated, but soon 
 rushed back again with greater violence, bringing with it 
 some of the people and animals it had carried away. At the 
 same time every boat was sunk or dashed against the beach, 
 and some of them were swept far inland. The aged prince, 
 with 1,430 of his people, was destroyed. 
 
 State of Stromboli and Etna during the shocks. The in- 
 habitants of Pizzo remarked that, on February 5, 1783, 
 
CH. XXIX.] ORIGIN OF EARTHQUAKE- WAVES. 135 
 
 when the first great shock afflicted Calabria, the volcano of 
 Stromboli, which is in fall view of that town, and at the 
 distance of about 50 miles, smoked less, and threw up a less 
 quantity of inflamed matter, than it had done for some years 
 previously. On the other hand, the great crater of Etna is 
 said to have given out a considerable quantity of vapour 
 towards the beginning, and Stromboli towards the close, of 
 the commotions. But as no eruption happened from either 
 of these great vents during the whole earthquake, the sources 
 of the Calabrian convulsions, and of the volcanic fires of Etna 
 and Stromboli, appear to be very independent of each other ; 
 unless, indeed, they have the same mutual relation as Vesuvius 
 and the volcanos of the Phlegrsean Fields and Ischia, a violent 
 disturbance in one district serving as a safety-valve to the 
 other, and both never being in full activity at once. 
 
 Origin and mode of propagation of earthquake-waves. We 
 have already hinted in Chapter XXIII. that there are good 
 reasons for suspecting that the subterranean causes of the 
 earthquake and volcano are the same. In what manner 
 portions of the solid crust of the earth may be melted from 
 time to time so as to form reservoirs of fused matter at 
 various depths, will be considered in Chapter XXXII. 
 Assuming for the present the existence of such reservoirs of 
 liquid lava in the interior, it is not difficult to understand 
 how steam may be generated whenever rain-water or the 
 waters of the sea, percolating through rocks, gain access to 
 such lava, and how when steam is generated, the incumbent 
 crust of the earth may be rent and dislocated. 
 
 During such movements fissures may be formed and 
 injected with gaseous or fluid matter, which may sometimes 
 fail to reach the surface, while at other times it may be 
 expelled through volcanic vents, stufas and hot springs. 
 When the strain on the rocks has caused them to split, or 
 the roofs of pre-existing fissures or caverns have been made 
 to fall in, vibratory jars will be produced and propagated in 
 all directions, like waves of sound through the crust of the 
 earth with varying velocity, according to the violence of the 
 original shock, and the density or elasticity of the substances 
 through which they pass. They will travel, for example, 
 
136 EARTHQUAKES IN THE EIGHTEENTH CENTURY. [On. XXIX. 
 
 faster through granite than through limestone, and more 
 rapidly through the latter than through wet clay, but the 
 rate will be uniform through the same homogeneous medium. 
 To the inhabitants of a shaken district the wave or vibration 
 appears to radiate horizontally, outwards from the spot on 
 the surface where it is first felt ; but the force does not 
 really operate in a horizontal direction like a wave caused by 
 a pebble on the surface of a pond, for at every point except 
 that immediately above the focus of the shock it comes up 
 obliquely from below, causing the ground to move forwards 
 
 Diagram showing the mode in which an earthquake-wave is transmitted from 
 a subterranean focus of disturbance such as A. 
 
 A. Focus of earthquake. 
 
 B. Seismic vertical, or point where the shock 
 first reaches the surface. 
 
 C. Supposed focus of greater depth. Here 
 the line C, 1, representing the angle of emerg- 
 ence, is steeper than the line A, 1. (See p. 
 139.) 
 
 c, c', d, d'. Section of spherical shells show- 
 ing the manner in which the earthquake-wave 
 is propagated in all directions from the centre 
 of disturbance, A. 
 
 1, 1', Coseismic points, or points on the 
 surface reached simultaneously by the earth- 
 quake-wave. So also 2, 2'. 3, 3'. 
 
 and then backwards in a more or less horizontal direction, 
 so that all objects which do not participate fully in the 
 movements, such as the walls of a building, appear to move 
 in a direction contrary to that of the ground, and fall by 
 their own weight or inertia. The mode in which the wave 
 is transmitted will be best understood by the accompanying 
 diagram, fig. 120. Suppose the subterranean centre of dis- 
 turbance to be several miles below the surface or at A, the 
 crust of the earth being homogeneous, the shock will 
 
CH. XXIX.] MOTION OF THE EAKTHQUAKE-WAVES. 137 
 
 proceed in all directions as a wave of compression displacing 
 the particles of the vibrating medium for a certain space, 
 and then allowing them to recover their original position 
 usually without fracture of the rock. The wave moves in 
 the form of a series of spherical shells, sections of which are 
 represented in the diagram at c c', d d', &c. When the 
 movement extends to the circle d d f the earthquake will be 
 first felt at the surface at a point immediately above A. 
 This point B, where the shock will be felt most violently by 
 the inhabitants as being nearest to the original impulse, is 
 called the seismic vertical. The vibrations will reach the 
 points 1 and V some seconds later according to the distance 
 of such points from the focus A. The wave will successively 
 reach the points 2 and 2', and 3 and 3', and its emergence 
 at the surface of the country will take place in a series of 
 concentric rings receding farther and farther from B where 
 the shock was first felt, as in fig. 121. The wave therefore, 
 or vibratory jar, although having the appearance of being 
 propagated horizontally in all directions from B, is in reality 
 transmitted direct from A. The circles 1 V and 2 2' in figs. 
 
 120 and 121 are called coseismal F . 191 
 
 - LJ H > ** 
 
 circles, because all points in their 
 
 circumference are simultaneously 
 
 shaken. The reader will observe 
 
 that all these spherical shells c and 
 
 c', d and d f , and the points of 
 
 emergence, 1, 2, 3, &c., relate to 
 
 the continuous transmission through 
 
 the earth of a single shock, and 
 
 not to a series of separate waves 1 
 
 following each other. Mr. Robert 
 
 Mallet and the late Mr. Hopkins have endeavoured to devise 
 
 instruments and methods of observation, by which the rate of 
 
 transit of the earthquake -wave, and the depth of the focus of 
 
 disturbance, might be measured. 
 
 Mr. Mallet * has the merit of having been the first to make 
 a practical application of the rules deduced from mechanical 
 
 * Great Neapolitan Earthquake of 1857; in two vols. London, 1862. 
 
138 EAKTHQUAKES IN THE EIGHTEENTH CENTURY. [Cn. XXIX. 
 
 principles bearing on this subject. With this object he 
 visited part of the Neapolitan territory, shortly after the 
 great earthquake of December, 1857. The region most 
 violently shaken at that period was about 40 miles east of 
 Salerno, in latitude 40 30' N., wholly to the north of the 
 district convulsed in 1783. Although many towns were then 
 laid in ruins, and there was much loss of life, the destruction 
 was by no means so great as that of 1783, and the changes 
 wrought in the river-courses were not on so grand a scale. 
 
 To obtain the seismic vertical Mr. Mallet observed the 
 direction in which chimneys, urns, and statues had been 
 thrown down from the tops of high buildings. Such bodies 
 in consequence of their inertia usually fall backwards in the 
 direction from which the shock comes, but sometimes they 
 are thrown forwards. In either case they indicate the 
 direction of the shocks, and two or more such lines of 
 direction prolonged to their point of intersection give the 
 seismic vertical. That point being found, the next step is to 
 ascertain the angle at which the wave emerged at different 
 points at the surface. 
 
 Suppose a rectangular building d, e,f, y (fig. 122), to stand 
 with its principal walls in the direction of the shock, and the 
 Fig. 122. earthquake-wave to emerge in 
 
 c the direction A, C. The shock 
 
 will tend to produce fissures 
 h h', i i', at right angles to its 
 
 eh ' ' ' 
 
 / own path. The inclination of 
 
 - A, C, to the horizon, or the 
 angle of emergence, being thus 
 known by reference to these 
 fissures, we obtain the position 
 of the focus A, by imagining 
 the line c, h f , to be prolonged 
 till it meets the vertical line 
 B,A. 
 
 A By referring to the former 
 
 diagram, fig. 120, the reader will at once see that the angle 
 of emergence of the wave at any given distance from the 
 seismic vertical, B, will depend upon the depth of the focus; 
 
CH. XXIX.] THEORY OF THE EARTHQUAKE-WAVE. 139 
 
 in other words, it will be always steeper as the depth 
 increases, as the line C, 1, for example, is more steeply 
 inclined than A, 1. 
 
 By aid of a dynamical formula which we need not cite 
 here, Mr. Mallet came to the conclusion that the depth of 
 the original shock in 1857 did not exceed 7 or 8 miles, and 
 although this can only be a rough approximation to the 
 truth it is of considerable interest, and the repetition of 
 such investigations may hereafter lead to more reliable 
 results, especially when observations in regard to the time, 
 direction, and intensity of the shocks shall have been made 
 with scientific care at the moment of the convulsion. Such 
 observations require the aid of delicate instruments, and 
 the problem is exceedingly complicated, far more so than 
 the reader may have inferred from the simple illustration 
 above given. For in the first place the shock which 
 produces the vibration or earthquake- wave does not give rise 
 to a single movement, as above supposed, but to two move- 
 ments, one longitudinal and the other transverse ; the second 
 of which at the outset follows the principal one almost instan- 
 taneously, and is at right angles to it ; but, as this latter 
 vibration travels somewhat slower than the former, it reaches 
 the surface, if the distance be considerable, after a distinct 
 interval of time and often does more mischief to buildings than 
 the first. It will also be seen by the elaborate report of Mr. 
 Hopkins * that the earthquake-wave when it passes through 
 rocks differing in density and elasticity, changes in some degree 
 not only its velocity but its direction, being both refracted and 
 reflected in a manner analogous to that of light when it passes 
 from one medium to another of a different density. When the 
 shock traverses the earth's crust through a thickness of several 
 miles, it will encounter a great variety of rocks as well as 
 rents and faults by which the course of the vibratory move- 
 ments will be more or less interfered with. The fracture 
 also of buildings is considerably modified by the nature of 
 their component materials, and of the coherence of the 
 mortar by which stones or bricks are cemented together. 
 
 * Geological Theories of Elevation and Earthquakes, Brit. Assoc. 1847, p. 33. 
 
140 EARTHQUAKES IN THE EIGHTEENTH CENTURY. [Cir. XXIX. 
 
 We must make due allowance therefore for the uncertainty 
 of the data at Mr. R. Mallet's disposal when he attempted to 
 compute the depth beneath the surface at which the shock of 
 1857 originated, and it is still more difficult for us to form a 
 probable conjecture as to the distance from the surface from 
 which the subterranean movements of 1783 may have pro- 
 ceeded. It is a matter, however, of general interest that Mr. 
 Mallet deduces from all the facts at present known to him 
 respecting the movements of earthquakes, that the subterra- 
 nean points where the shocks originate are never very deep, 
 perhaps never exceeding thirty geographical miles ; a very 
 important conclusion should it hereafter be confirmed by 
 observation and theory. 
 
 Number of persons who perished during the earthquake of 
 1783. The number of persons who perished during the 
 earthquake in the two Calabrias and Sicily, is estimated by 
 Hamilton at about 40,000 ; and about 20,000 more died by 
 epidemics, which were caused by insufficient nourishment, 
 exposure to the atmosphere, and malaria, arising from the 
 new stagnant lakes and pools. 
 
 By far the greater number were buried under the ruins of 
 their houses ; but many were burnt to death in the confla- 
 grations which almost invariably followed the shocks. These 
 fires raged the more violently in some cities, such as Oppido, 
 from the immense magazines of oil which were consumed. 
 
 Many persons were engulfed in deep fissures, especially the 
 peasants when flying across the open country, and their 
 skeletons may perhaps be buried at various depths in the 
 earth to this day. 
 
 When Dolomieu visited Messina after the shock of Febru- 
 ary 5, he describes the city as still presenting, at least at a 
 distance, an imperfect image of its ancient splendour. Every 
 house was injured, but the walls were standing : the whole 
 population had taken refuge in wooden huts in the neigh- 
 bourhood, and all was solitude and silence in the streets : it 
 seemed as if the city had been desolated by the plague, and 
 the impression made upon his feelings was that of melancholy 
 and sadness. c But when I passed over to Calabria, and first 
 beheld Polistena, the scene of horror almost deprived me of 
 
CH. XXIX.] INCIDENTS AT TERKANUOVA. 141 
 
 my faculties ; my mind was filled with mingled compassion 
 and terror ; nothing had escaped ; all was levelled with the 
 dust ; not a single house or piece of wall remained ; on all 
 sides were heaps of stone so destitute of form, that they gave 
 110 conception of there ever having been a town on the spot. 
 The stench of the dead bodies still rose from the ruins. I 
 conversed with many persons who had been buried for three, 
 four, or even for five days ; I questioned them respecting 
 their sensations in so dreadful a situation, and they agreed 
 that, of all the physical evils they endured, thirst was the 
 most intolerable ; and that their mental agony was increased 
 by the idea that they were abandoned by their friends, who 
 might have rendered them assistance.' * 
 
 It is supposed that about a fourth part of the inhabitants 
 of Polistena, and of some other towns, were buried alive, and 
 might have been saved had there been no want of hands ; 
 but in so general a calamity, where each was occupied with 
 his own misfortunes or those of his family, aid could rarely be 
 obtained. Neither tears, nor supplications, nor promises of 
 high rewards were listened to. Many acts of self-devotion, 
 prompted by parental and conjugal tenderness, or by friend- 
 ship, or the gratitude of faithful servants, are recorded; but 
 individual exertions were, for the most part, ineffectual. It 
 frequently happened, that persons in search of those most 
 dear to them could hear their moans could recognise their 
 voices were certain of the exact spot where they lay buried 
 beneath their feet, yet could afford them no succour. The 
 piled mass resisted all their strength, and rendered their 
 efforts of 110 avail. 
 
 At Terranuova, four Augustin monks, who had taken refuge 
 in a vaulted sacristy, the arch of which continued to support 
 an immense pile of ruins, made their cries heard for the space 
 of four days. One only of the brethren of the whole convent 
 was saved, and ' of what avail was his strength to remove the 
 enormous weight of rubbish which had overwhelmed his 
 companions ?' He heard their voices die away gradually ; 
 and when afterwards their four corpses were disinterred, they 
 
 * Pinkerton's Voyages and Travels, vol. v. as cited above, p. 117, note. 
 
142 EARTHQUAKES IN THE EIGHTEENTH CENTURY. [Cn. XXIX. 
 
 were found clasped in each other's arms. Affecting narratives 
 are preserved of mothers saved after the fifth, sixth, and even 
 seventh day of their interment, when their infants or children 
 had perished with hunger. 
 
 It might have been imagined that the sight of sufferings 
 such as these would have been sufficient to awaken senti- 
 ments of humanity and pity in the most savage breasts ; but 
 while some acts of heroism are related, nothing could exceed 
 the general atrocity of conduct displayed by the Calabrian 
 peasants : they abandoned the farms, and flocked in great 
 numbers into the towns not to rescue their countrymen 
 from a lingering death, but to plunder. They dashed through 
 the streets, fearless of danger, amid tottering walls and 
 clouds of dust, trampling beneath their feet the bodies of the 
 wounded and half-buried, and often stripping them, while 
 yet living, of their clothes.* 
 
 But to enter more fully into these details would be foreign 
 to the purpose of the present work, and several volumes would 
 be required to give the reader a just idea of the sufferings 
 which the inhabitants of many populous districts have under- 
 gone during the earthquakes of the last 150 years. A bare 
 mention of the loss of life as that 50,000 or 100,000 souls 
 perished in one catastrophe conveys to the reader no idea 
 of the extent of misery inflicted : we must learn, from the 
 narratives of eye-witnesses, the various forms in which death 
 was encountered, the numbers who escaped with loss of limbs 
 or serious bodily injuries, and the multitude who were sud- 
 denly reduced to penury and want. It has been often re- 
 marked, that the dread of earthquakes is strongest in the 
 minds of those who have experienced them most frequently ; 
 whereas, in the case of almost every other danger, familiarity 
 with peril renders men intrepid. The reason is obvious 
 scarcely any part of the mischief apprehended in this instance 
 is imaginary ; the first shock is often the most destructive ; 
 and, as it may occur in the dead of the night, or if by day, 
 without giving the least warning of its approach, no fore- 
 thought can guard against it ; and when the convulsion has 
 
 * Dolomieu, Pinkerton's Voyages and Travels, vol. v. 
 
Cu. XXIX.] SITE OF ANCIENT CALABRIAN TOWNS. 143 
 
 begun, no skill,, or courage or presence of mind, can point 
 out the path, of safety. During the intervals, of uncertain 
 duration, (lasting perhaps for centuries) between the more 
 fatal shocks, slight tremors of the soil are not unfrequent ; 
 and as these sometimes precede more violent convulsions, 
 they become a source of anxiety and alarm. The terror 
 arising from this cause alone is of itself no inconsiderable 
 evil. 
 
 Although sentiments of pure religion are frequently 
 awakened by these awful visitations, yet we more commonly 
 find that an habitual state of fear, a sense of helplessness, 
 and a belief in the futility of all human exertions, prepare 
 the minds of the vulgar for the influence of a demoralising 
 superstition. 
 
 Where earthquakes are frequent, there can never be perfect 
 security of property under the best government; industry 
 cannot be assured of reaping the fruits of its labour ; and the 
 most daring acts of outrage may occasionally be perpetrated 
 with impunity, when the arm of the law is paralysed by the 
 general consternation. It is hardly necessary to add, that 
 the progress of civilisation and national wealth must be re- 
 tarded by convulsions which level cities to the ground, destroy 
 harbours, throw down bridges, render roads impassable, and 
 cause the most cultivated valley-plains to be covered with 
 lakes, or the ruins of adjoining hills. 
 
 In regions exposed to the frequent recurrence of severe 
 shocks, experience and scientific knowledge might, no doubt, 
 alleviate the evil. 
 
 The Calabrian towns of mediaeval date were most of them 
 perched, for the purposes of defence and security, on the tops 
 of isolated hills, where they are said to be rocked by every 
 shock like sailors on the top of a mast.* The same sites have 
 usually precipices on several sides, over the edges of which 
 the tottering buildings may readily be precipitated together 
 with some of the ground on which their foundations repose. 
 When towns are placed in the more open country, and con- 
 structed on such a plan, and of such materials as are best 
 
 * Mallet, Neapolitan Earthquake of 1857, vol. i. p. 30. 
 
144 EARTHQUAKES IN THE EIGHTEENTH CENTURY. [Cn. XXIX. 
 
 suited to lessen the danger, the loss of life must be sensibly 
 diminished. That architects do not despair of successfully 
 contending with the danger, is shown by their frequently 
 advertising their houses in Sicily as earthquake-proof. 
 
 I shall endeavour to point out in the sequel, that the 
 general tendency of subterranean movements, when their 
 effects are considered for a sufficient lapse of ages, is emi- 
 nently beneficial, and that they constitute an essential part 
 of that mechanism by which the integrity of the habitable 
 surface is preserved, and the very existence and perpetuation 
 of dry land secured. Why the working of this same machi- 
 nery should be attended with so much evil, is a mystery far 
 . beyond the reach of our philosophy, a,nd must probably remain 
 so until we are permitted to investigate, not our planet alone 
 and its inhabitants, but other parts of the moral and material 
 universe with which they may be connected. Could our 
 survey embrace other worlds, and the events, not of a few 
 centuries only, but of periods as indefinite as those with 
 which geology renders us familiar, some apparent contradic- 
 tions might be reconciled, and some difficulties would doubt- 
 less be cleared up. But even then, as our capacities are 
 finite, while the scheme of the universe may be infinite, both 
 in time and space, it is presumptuous to suppose that all 
 sources of doubt and perplexity would ever be removed. On 
 the contrary, they might, perhaps, go on augmenting in 
 number, although our confidence in the wisdom of the plan 
 of Nature should increase at the same time ; for it has been 
 justly said, that the greater the circle of light, the greater the 
 boundary of darkness by which it is surrounded.* 
 
 * Sir H. Davy, Consolations in Travel, p. 246. 
 
CH. XXX.] EARTHQUAKE OF JAVA. 145 
 
 CHAPTER XXX. 
 
 EARTHQUAKES continued. 
 
 EARTHQUAKE OF JAVA, 1772 TRUNCATION OF A LOFTY CONE ST. DOMINGO, 
 
 1770 LISBON, 1775 GREAT AREA OVER WHICH THE SHOCKS EXTENDED 
 
 RETREAT OF THE SEA PROPOSED EXPLANATIONS CONCEPTION BAY, 1750 
 
 PERMANENT ELEVATION PERU, 1746 JAVA, 1699 RIVERS OBSTRUCTED BY 
 
 LANDSLIPS SUBSIDENCE IN SICILY, 1693 MOLUCCAS, 1693 JAMAICA, 1692 
 
 LARGE TRACTS ENGULFED PORTION OF PORT ROYAL SUNK AMOUNT OF 
 
 CHANGE IN THE LAST 170 YEARS ELEVATION AND SUBSIDENCE OF LAND IN BAY 
 OF BAL3S EVIDENCE OF THE SAME AFFORDED BY THE TEMPLE OF SERAPIS. 
 
 IN this chapter, I shall conclude my remarks on the earth- 
 quakes of the 18th century, and then pass on to those of 
 earlier date respecting which we have information which may 
 be of interest to the geologist. 
 
 Java, 1772. Truncation of a lofty cone. In the year 1772, 
 Papandayang, formerly one of the loftiest volcanos in the 
 island of Java, was in eruption. Before all the inhabitants 
 on the declivities of the mountain could save themselves by 
 flight, the ground is said to have given way, and a great part 
 of the volcano to have fallen in and disappeared. It was 
 estimated that an extent of ground of the mountain itself 
 and its immediate environs, 15 miles long and full 6 broad, 
 was by this commotion swallowed up in the bowels of the 
 earth. Forty villages were destroyed, some being engulphed 
 and some covered by the substances thrown out on this 
 occasion, and 2,957 of the inhabitants perished. A pro- 
 portionate number of cattle were also killed, and most of the 
 plantations of cotton, indigo, and coffee in the adjacent 
 districts were buried under the volcanic matter. This cata- 
 strophe appears to have resembled, although on a grander 
 scale, that of the ancient Vesuvius in the year 79. The cone 
 was reduced in height from 9,000 to about 5,000 feet ; and, 
 
 VOL. II. L 
 
14G EARTHQUAKE OF HINDOSTAK [On. XXX. 
 
 as vapours still escape from the crater on its summit, a new 
 cone may one day rise out of the ruins of the ancient moun- 
 tain, as the modern Vesuvius has risen from the remains of 
 Somma.*" 
 
 Junghuhn, who examined the mountain in 1842, was 
 unable to obtain positive proof that there had been a sinking 
 in of the ground, and concluded that, if any, it must have 
 been near the summit of the cone, or where a new crater was 
 formed. He found that the town and villages destroyed 
 were far distant from the summit, and buried under a mass 
 of ejected materials ; so that they seem to have suffered the 
 fate of Herculaneum and Pompeii, and the lowering of the 
 mountain was probably due for the most part to explosion, 
 rather than to engulfment. 
 
 St. Domingo, 1770. During a tremendous earthquake 
 which destroyed a great part of St. Domingo, innumerable 
 fissures were caused throughout the island, from which 
 mephitic vapours emanated and produced an epidemic. Hot 
 springs burst forth in many places where there had been no 
 water before ; but after a time they ceased to flow.f 
 
 In a previous earthquake, in November 1751, a violent 
 shock destroyed the capital, Port au Prince, and part of the 
 coast, twenty leagues in length, sank down, and has ever 
 since formed a bay of the sea. J 
 
 Hindostan, 1762. The town of Chittagong, in Bengal, was 
 violently shaken by an earthquake, on April 2, 1762, the 
 earth opening in many places, and throwing up water and 
 mud of a sulphureous smell. At a place called Bardavan, a 
 large river was dried up ; and at Bar Charra, near the sea, a 
 tract of ground sank down, and 200 people, with all their 
 cattle, were lost. It is said, that 60 square miles of the 
 Chittagong coast suddenly and permanently subsided during 
 this earthquake, and that Ces-lung-Toom, one of the Mug 
 mountains, entirely disappeared, and another sank so low, 
 that its summit only remained visible. Four hills are also 
 
 * Dr. Horsfield, Eatav. Trans, vol. f Essai sur 1'Ifist. Nat. de 1'Isle do 
 
 viii. p. 26. Baffles's account (History St. Domingue. Paris, 1776. 
 of Java, vol. i.) is derived from Hors- J Hist, de 1'Acad. des Sciences, 
 
 field. 1752. Paris. 
 
CH. XXX.]. EARTHQUAKE OF LISBON. 147 
 
 described as having been variously rent asunder, leaving open 
 chasms from 30 to 60 feet in width. Towns which subsided 
 several cubits, were overflowed with water ; among others, 
 Deep Gong, which was submerged to the depth of 7 cubits. 
 Two volcanos are said to have opened in the Secta Cunda 
 hills. The shock was also felt at Calcutta.* While the 
 Chittagong coast was sinking, a corresponding rise of the 
 ground took place at the island of Ramree, and at Cheduba. 
 (See Map, fig. 59, Vol. I. p. 587.) f 
 
 Earthquake of Lisbon, 1755. Extent of the shock. In no 
 part of the volcanic region of southern Europe, has so 
 tremendous an earthquake occurred in modern times as that 
 which began on November 1, 1755, at Lisbon. The in- 
 habitants had had no warning of the coming danger, when a 
 sound like that of thunder was heard underground, and 
 immediately afterwards a violent shock threw down the 
 greater part of their city. In the course of about six minutes, 
 60,000 persons perished. The sea first retired and laid the 
 bar dry ; it then rolled in, rising 50 feet or more above its 
 ordinary level- The mountains of Arrabida, Estrella, Julio, 
 Marvan, and Cintra, being some of the largest in Portugal, 
 were impetuously shaken, as it were, from their very foun- 
 dations ; and some of them opened at their summits, which 
 were split and rent in a wonderful manner, huge masses 
 of them being thrown down into the subjacent valley s.J 
 Flames are related to have issued from these mountains, 
 which are supposed to have been electric ; they are also said 
 to have smoked ; but vast clouds of dust may have given rise 
 to this appearance. 
 
 Subsidence of the quay. Among other extraordinary events 
 related to have occurred at Lisbon during the catastrophe, 
 was the subsidence of a new quay, built entirely of marble 
 at an immense expense. A great concourse of people had 
 collected there for safety, as a spot where they might be 
 
 * M'Clelland's Report on Min. Re- f Journ. Asiat. Soc. Bengal, vol. x. 
 
 sources of India, 1838. Calcutta. For pp. 351, 433. 
 
 other particulars, see Phil. Trans, vol. \ Hist, and Philos. of Earthquakes, 
 
 liii. p. 317. 
 
 L 2 
 
148 EARTHQUAKE OF LISBON. .[Cn.XXX. 
 
 beyond the reach of falling rnins ; but suddenly the quay 
 sank down with all the people on it, and not one of the dead 
 bodies ever floated to the surface. A great number of boats 
 and small vessels anchored near it, all full of people, were 
 swallowed up, as in a whirlpool.* No fragments of these 
 wrecks ever rose again to the surface, and the water in the 
 place where the quay had stood is stated, in many accounts, 
 to be unfathomable ; but Whitehurst says he ascertained it 
 to be 100 fathoms.f 
 
 Circumstantial as are the contemporary narratives, I was 
 informed by Mr. F. Freeman, in 1841, that no part of the 
 Tagus was then more than 30 feet deep at high tide, and an 
 examination of the position of the new quay, and the 
 memorials preserved of the time and manner in which it was 
 built, render the statement of so great a subsidence in 1755 
 quite unintelligible. Perhaps a deep narrow chasm, such as 
 was before described in Calabria (p. 125), opened and closed 
 again in the bed of the Tagus, after swallowing up some 
 incumbent buildings and vessels. We have already seen 
 that such openings may collapse after the shock suddenly, or 
 in places where the strata are of soft and yielding materials, 
 very gradually. According to the observations made at 
 Lisbon, in 1837, by Mr. Sharpe, the destroying effects of this 
 earthquake were confined to the tertiary strata, and were 
 most violent on the blue clay, on which the lower part of the 
 city is constructed. Not a building, he says, on the secondary 
 limestone or the basalt was injured. J 
 
 The area over which this convulsion extended is very 
 remarkable. It has been computed, says Humboldt, that 
 on November 1, 1755, a portion of the earth's surface four 
 times greater than the extent of Europe was simultaneously 
 shaken. The shock was felt in the Alps, and on the coast of 
 Sweden, in small inland lakes on the shores of the Baltic, in 
 Thuringia, in the flat country of northern Germany, and in 
 
 * Rev. C. Davy's Letters, vol. ii. f On the Formation of the Earth, 
 
 Letter ii. p. 12, who was at Lisbon at p. 55. 
 
 the time, and ascertained that the boats j Geol. Soc. Proceedings, No. 60, 
 
 and vessels said to have been swallowed p. 06. 1838. 
 
 were missing Cosmos, vol. i. 
 
CH. XXX.] SHOCKS AT SEA. 149 
 
 Great Britain. The thermal springs of Toplitz dried up, and 
 again returned, inundating everything with water discoloured 
 by ochre. In the islands of Antigua, Barbadoes, and Mar- 
 tinique in the West Indies, where the tide usually rises little 
 more than 2 feet, it suddenly rose above 20 feet, the water 
 being discoloured and of an inky blackness. The movement 
 was also sensible in the great lakes of Canada. At Algiers 
 and Fez, in the north of Africa, the agitation of the earth 
 was as violent as in Spain and Portugal ; and at the distance 
 of 8 leagues from Morocco, a village with the inhabitants, to 
 the number of about 8,000 or 10,000 persons, is said to have 
 been swallowed up ; the earth soon afterwards closing over 
 them. 
 
 Shocks fdt at sea. The shock was felt at sea, on the deck 
 of a ship to the west of Lisbon, and produced very much the 
 same sensation as on dry land. Off St. Lucar, the captain 
 of the ship Nancy felt his vessel so violently shaken, that he 
 thought she had struck the ground ; but, on heaving the 
 lead, found a great depth of water. Captain Clark, from 
 Denia, in latitude 36 24' 1ST., between 9 and 10 in the 
 morning, had his ship shaken and strained as if she had 
 struck upon a rock, so that the seams of the deck opened, 
 and the compass was overturned in the binnacle. Another 
 ship, 40 leagues west of St. Yincent, experienced so violent 
 a concussion, that the men were thrown a foot and a half 
 perpendicularly up from the deck. 
 
 Rate at which the movement travelled. The agitation of 
 lakes, rivers, and springs, in Great Britain, was remarkable. 
 At Loch Lomond, in Scotland, for example, the water, with- 
 out the least apparent cause, rose against its banks, and then 
 subsided below its usual level. This is explained by sup- 
 posing that the water does not partake of the sudden shove 
 given to the land, so that it dashes over that side of the 
 basin from which the shock is given. The greatest perpen- 
 dicular height of the rise in Loch Lomond was 2 feet 4 
 inches. It is said that the undulatory movement of this 
 earthquake travelled at the rate of 20 miles a minute, its 
 velocity being calculated by the intervals between the time 
 
150 EARTHQUAKE OF LISBON. [Cn. XXX. 
 
 when, the first shock was felt at Lisbon, and its time of 
 occurrence at several distant places.* 
 
 Great wave and retreat of the sea. A great wave swept 
 over the coast of Spain, and is said to have been 60 feet high 
 at Cadiz. At Tangier, in Africa, it rose and fell 18 times on 
 the coast. At Funchal, in Madeira, it rose full 15 feet per- 
 pendicular above high-water mark, although the tide, which 
 ebbs and flows there 7 feet, was then at half ebb. Besides 
 entering the city, and committing great havoc, it over- 
 flowed other seaports in the island. At Kinsale, in Ireland, 
 a body of water rushed into the harbour, whirled round 
 several vessels, and poured into the market-place. 
 
 It was before stated that the sea first retired at Lisbon ; 
 and this retreat of the ocean from the shore, at the com- 
 mencement of an earthquake, and its subsequent return in a 
 violent wave, is a common occurrence. In order to account 
 for the phenomenon, Michell imagined a subsidence at the 
 bottom of the sea, from the giving way of the roof of some 
 cavity in consequence of a vacuum produced by the conden- 
 sation of steam. Such condensation, he observes, might be 
 the first effect of the introduction of a large body of water 
 into fissures and cavities already filled with steam, before 
 there has been sufficient time for the heat of the incandescent 
 lava to turn so large a supply of water into steam, which 
 being soon accomplished causes a greater explosion. 
 
 Another proposed explanation is, the sudden rise of the 
 land, which would cause the sea to abandon immediately the 
 ancient line of coast ; and if the shore, after being thus 
 heaved up, should fall again to its original level, the ocean 
 would return. This theory, however, will not account for 
 the facts observed during the Lisbon earthquake ; for the 
 retreat preceded the wave, not only on the coast of Portugal, 
 but also at the island of Madeira, and several other places. 
 If the upheaving of the coast of Portugal had caused the 
 retreat, the motion of the waters, when propagated to 
 Madeira, would have produced a wave previous to the retreat. 
 
 The shock transmitted through the earth from Lisbon, 
 
 * Geol. Soc. Proceedings, No. 60, p. 36. 1838. 
 
CH.XXX.] EAKTHQUAKE-WAVES IN THE SEA, 151 
 
 reached Madeira in 25 minutes, and the sea-wave took 2-^ 
 hours to travel the same distance, which agrees well with the 
 time which it required to reach other places according to 
 their distance. We cannot, therefore, explain the great 
 motion of the waters at Madeira, by a momentary upward 
 movement of the solid crust of the earth, for in that case the 
 rise of the beach would have occurred at the first period or 
 25 minutes after the Lisbon shock ; besides, it will be seen in 
 the sequel, page 153, that where the sea is deep near the shore, 
 and the beach very steep, as in Madeira, the land-wave can^ 
 not cause a retreat of the .sea. 
 
 The following is another solution of the problem, which 
 has been offered: Suppose a portion of the bed of the sea 
 to be suddenly upheaved ; the first effect will be to raise over 
 the elevated part a body of water, the momentum of which 
 will carry it much above the level it will afterwards assume, 
 causing a draught or receding of the water from the neigh- 
 bouring coasts, followed immediately by the return of the 
 displaced water, which will also be impelled by its momentum 
 much farther and higher on the coast than its former level.* 
 
 Mr. Darwin, when alluding to similar waves on the coast 
 of Chili, states his opinion, that c the whole phenomenon is 
 due to a common undulation in the water, proceeding from a 
 line or point of disturbance some little way distant. If the 
 waves,' he says, c sent off from the paddles of a steam-vessel 
 be watched breaking on the sloping shore of a still river, the 
 water will be seen first to retire two or three feet, and then 
 to return in little breakers, precisely analogous to those con- 
 sequent on an earthquake/ He also adds, that ' the earth- 
 quake-wave occurs some time after the shock, the water at 
 first retiring both from the shores of the mainland and of 
 outlying islands, and then returning in mountainous breakers. 
 Their size is modified by the form of the neighbouring coast ; 
 for it is ascertained in South America, that places situated at 
 the head of shoaling bays have suffered most, whereas towns 
 like Valparaiso, seated close on the border of a profound 
 
 * Quarterly Review, No. Lxxxvi. p. 459. 
 
152 EAKTHQUAKE OF LISBON. [Cn. XXX. 
 
 ocean, have never been inundated, though severely shaken 
 by earthquakes.'* 
 
 More recently (February, 1846), Mr. Mallet, in his memoir 
 above cited (p. 137), has endeavoured to bring to bear on this 
 difficult subject the more advanced knowledge obtained of 
 late years respecting the true theory of waves. He conceives 
 that when the origin of the shock is beneath the deep ocean, 
 one wave is propagated through the land, and another 
 moving with inferior velocity is formed on the surface of the 
 ocean. This last rolls in upon the land long after the earth- 
 wave has arrived and spent itself. However irreconcilable 
 it may be to our common notions of solid bodies, to imagine 
 them capable of transmitting, with such extreme velocity, 
 motions analogous to tidal waves, it seems nevertheless cer- 
 tain that such undulations are produced, and it is supposed 
 that when the shock passes a given point, each particle of 
 the solid earth describes an ellipse in space. The facility 
 with which all the particles of a solid mass can be made to 
 vibrate maybe illustrated, says Gay-Lussac, by many familiar 
 examples. If we apply the ear to one end of a long wooden 
 beam, and listen attentively when the other end is struck by 
 a pin's head, we hear the shock distinctly ; which shows that 
 every fibre throughout the whole length has been made to 
 vibrate. The rattling of carriages on the pavement shakes 
 the largest edifices ; and in the quarries underneath some 
 quarters in Paris, it is found that the movement is communi- 
 cated through a considerable thickness of rock.f 
 
 The great sea-wave originating directly over the centre of 
 disturbance is propagated, as Michell correctly stated, in 
 every direction, like the circle upon a pond when a pebble is 
 dropped into it, the different rates at which it moves depend- 
 ing (as he also suggested) on variations in the depth of the 
 water. This wave of the sea, says Mr. Mallet, is raised by 
 the impulse of the shock immediately below it, which in 
 great earthquakes lifts up the ground 2 or 3 feet perpendicu- 
 larly. The velocity of the shock, or earth-wave, is greater 
 
 * Darwin's Travels in South Ame- t Ann. de. Ch. et de Ph. torn. xxii. 
 
 rica, &c. 1832 to 1836. Voyage of p. 428. 
 H.M.S. Beagle, vol. iii. p. 377, 
 
CH. XXX.] GREAT WAVE OF THE SEA. 153 
 
 because it ' depends upon a function of the elasticity of the 
 crust of the earth, whereas the velocity of the sea-wave 
 depends upon a function of the depth of the sea.' 
 
 6 Although the shock in its passage under the deep ocean 
 gives no trace of its progress, it no sooner gets into soundings 
 or shallow water, than it gives rise to another and smaller 
 wave of the sea. It carries, as it were, upon its back, this 
 lesser aqueous undulation; a long narrow ridge of water, 
 which corresponds in form and velocity to itself, being pushed 
 up by the partial elevation of the bottom. It is this small 
 wave, called technically the ' forced sea- wave,' which com- 
 municates the earthquake-shock to ships at sea, as if they 
 had struck upon a rock. It breaks upon a coast at the same 
 moment that the shock reaches it, and sometimes it may 
 cause an apparent slight recession from the shore, followed 
 by its flowing up somewhat higher than the usual tide mark : 
 this will happen where the beach is very sloping, as is usual 
 where the sea is shallow, for then the velocity of the low flat 
 earth-wave is such, that it slips, as it were, from under the 
 undulation in the fluid above. It does this at the moment 
 of reaching the beach, which it elevates by a vertical height 
 equal to its own, and as instantly lets drop again to its 
 former level.' 
 
 6 While the shock propagated through the solid earth has 
 thus travelled with extra rapidity to the land, the great sea- 
 w r ave has been following at a slower pace, though advancing 
 at the rate of several miles in a minute. It consists, in the 
 deep ocean, of a long low swell of enormous volume, having an 
 equal slope before and behind, and that so gentle that it 
 might pass under a ship without being noticed. But when 
 it reaches the edge of soundings, its front slope, like that of 
 a tidal wave under similar circumstances, becomes short and 
 steep, while its rear slope is long and gentle. If there be 
 water of some depth close into shore, this great wave may 
 roll in long after the shock, and do little damage : but if 
 the shore be shelving, there will be first a retreat of the 
 water, and then the wave will break upon the beach and roll 
 in far upon the land.' * 
 
 * Mallet, Proceed. Rov. Irish Acad. 1846. 
 
154 EARTHQUAKE IN CHILI. [Cn. XXX. 
 
 The various opinions which have been offered by Michell 
 and later writers, respecting the remote causes of earthquake 
 shocks in the interior of the earth, will more properly be 
 discussed in Chapter XXXIII. 
 
 Ghiliy 1751. On May 24, 1751, the ancient town of Con- 
 ception, otherwise called Penco, was totally destroyed by an 
 earthquake, and the sea rolled over it. (See plan of the 
 bay, fig. 104, p. 92.) The ancient port was rendered entirely 
 useless, and the inhabitants built another town about 10 
 miles from the sea-coast, in order to be beyond the reach of 
 similar inundations. At the same time, a colony recently 
 settled on the sea-shore of Juan Fernandez was almost entirely 
 overwhelmed by a wave which broke upon the shore. 
 
 It has been already stated, that in 1835, or 84 years after 
 the destruction of Penco, the same coast was overwhelmed 
 by a similar flood from the sea during an earthquake ; and 
 it is also known that 21 years before .(or in 1730), a like 
 wave rolled over these fated shores, in which many of the 
 inhabitants perished. A series of similar catastrophes has 
 also been tracked back as far as the year 1590,* beyond 
 which we have no memorials save those of oral tradition. 
 Molina," who has recorded the customs and legends of the 
 aborigines, tells us, that the Araucanian Indians, a tribe 
 inhabiting the country between the Andes and the Pacific, 
 including the part now called Chili, 'had among them a 
 tradition of a great deluge, in which only a few persons were 
 saved, who took refuge upon a high mountain called Thegtheg, 
 "the thundering," which had three points.' Whenever a 
 violent earthquake occurs, these people fly for safety to the 
 mountains, assigning as a reason, that they are fearful, 
 after the shock, that the sea will again return and deluge 
 the world. f 
 
 Notwithstanding the tendency of writers in his day to 
 refer all traditionary inundations to one remote period, 
 Molina remarks that this flood of the Araucanians 'was 
 probably very different from that of Noah.' We have, 
 indeed, no means of conjecturing how long this same tribe 
 
 * See Father Acosta's work; and Sir Jugs, vol. ii. p. 215. 
 "Woodbine Parish, Geol. Soc. Proceed- f Molina, Hist, of Chili, vol. ii. 
 
CH.XXX.] ELEVATION IN CONCEPTION BAY. 155 
 
 had flourished in Chili, but we can scarcely doubt, that if its 
 experience reached back even for three or four centuries, 
 several inroads of the ocean must have occurred within that 
 period. But the memory of a succession of physical events, 
 similar in kind, though distinct in time, can never be pre- 
 served by a people destitute of written annals. Before two 
 or three generations have passed away all dates are forgotten, 
 and even the events themselves, unless they have given 
 origin to some customs, or religious rites and ceremonies. 
 Oftentimes the incidents of many different earthquakes and 
 floods become blended together in the same narrative ; and 
 in such cases the single catastrophe is described in terms so 
 exaggerated, or is so disguised by mythological fictions, as 
 to be utterly valueless to the man of science. 
 
 Proofs of elevation of the coast. During a late survey of 
 Conception Bay, Captains Beechey and Sir E. Belcher dis- 
 covered that the ancient harbour, which formerly admitted 
 all large merchant vessels which went round the Cape, is 
 now occupied by a reef of sandstone, certain points of which 
 project above the sea at low water, the greater part being 
 very shallow. A tract of 1J mile in length, where, accord- 
 ing to the report of the inhabitants, the water was for- 
 merly 4 or 5 fathoms deep, is now a shoal ; consisting, as 
 our hydrographers found, of hard sandstone, so that it 
 cannot be supposed to have been formed by recent deposits 
 of the river Biobio, an arm of which carries down loose 
 micaceous sand into the same bay. 
 
 It is impossible at this distance of time to affirm that the 
 bed of the sea was uplifted at once to the height of 24 feet, 
 during the single earthquake of 1751, because other move- 
 ments may have occurred subsequently ; but it is said, that 
 ever since the shock of 1751, no vessels have been able to 
 approach within 1^ mile of the ancient port of Penco. 
 (See Map, p. 92.) In. proof of the former elevation of the 
 coast near Penco, our surveyors found above high-water 
 mark an enormous bed of shells of the same species as those 
 now living in the bay, filled with micaceous sand like that 
 which the Biobio now conveys to the bay. These shells, as 
 well as others, which cover the adjoining hills of mica-schist 
 
156 EARTHQUAKE IN PERU. [Cn. XXX. 
 
 to the height of several hundred feet, have been examined 
 by experienced conchologists in London, and identified with 
 those taken at the same time in a living state from the bay 
 and its neighbourhood.* 
 
 Ulloa, therefore, was perfectly correct in his statement 
 that, at various heights above the sea between Talcahuano 
 and Conception, ' mines were found of various sorts of shells 
 used for lime of the very same kinds as those found in the 
 adjoining sea.' Among them he mentions the great mussel 
 called Choros, and two others which he describes. Some of 
 these, he says, are entire, and others broken ; they occur at 
 the bottom of the sea, in 4, 6, 10, or 12 fathom water, 
 where they adhere to a sea-plant called Cochayuyo. They 
 are taken in dredges, and have no resemblance to those 
 found on the shore or in shallow water ; yet beds of them 
 occur at various heights 011 the hills. 'I was the more 
 pleased with the sight,' he adds, 6 as it appeared to me 
 a convincing proof of the universality of the deluge, although 
 I am not ignorant that some have attributed their position 
 to ether causes.' f It has, however, been ascertained that 
 the foundation of the Castle of Penco was so low in 1835, 
 or at so inconsiderable an elevation above the highest spring 
 tides, as to discountenance the idea of any permanent up- 
 heaval in modern times, on the site of that ancient port ; 
 but no exact measurements or levellings appear as yet to 
 have been made to determine this point, which is the more 
 worthy of investigation, because it may throw some light 
 on an opinion often promulgated of late years, that there is 
 a tendency in the Chilian coast, after each upheaval, to sink 
 gradually and return towards its former position. . 
 
 Peru, 1746. Peru was visited, on October 28, 1746, by 
 a tremendous earthquake. In the first 24 hours, 200 shocks 
 were experienced. The ocean twice retired and returned 
 impetuously upon the land : Lima was destroyed, and part 
 of the coast near Callao was converted into a bay : 4 other 
 harbours, among which were Cavalla and Guanape, shared 
 
 * Captain Belcher showed me these f Ulloa's Voyage to South America, 
 
 shells, and the collection was examined vol. ii. book viii. ch. vi. 
 by Mr. Broderip. 
 
CH. XXX.] EARTHQUAKE IX PERU. 157 
 
 the same fate. There were 23 ships and vessels, great and 
 small, in the harbour of Callao, of which 19 were sunk ; and 
 the other 4, among which was a frigate called St. Ferniin, 
 were carried by the force of the waves to a great distance up 
 the country, and left on dry ground at a considerable height 
 above the sea. The number of inhabitants in this city 
 amounted to 4,000. 200 only escaped, 22 of whom were 
 saved 011 a small fragment of the fort of Yera Cruz, which 
 'remained as the only memorial of the town after this dreadful 
 inundation. Other portions of its site were completely 
 covered with heaps of sand and gravel. 
 
 A volcano in Luc anas burst forth the same night, and 
 such quantities of water descended from the cone that the 
 whole country was overflowed ; and in the mountain near 
 Pataz, called Conversiones de Caxamarquilla, three other 
 volcanos burst out, and frightful torrents of water swept 
 down their sides. * 
 
 There are several records of prior convulsions in Peru, 
 accompanied by similar inroads in the sea, one of which 
 happened 59 years before (in 1687), when the ocean, ac- 
 cording to Ulloa, first retired and then returned in a moun- 
 tainous wave, overwhelming Callao and its environs, with 
 the miserable inhabitants. f This same wave, according to 
 Lionel Wafer, carried ships a league into the country, and 
 drowned man and beast for 50 leagues along the shore. f 
 Inundations of still earlier dates are carefully recorded by 
 Ulloa, Wafer, Acosta, and various writers, who describe 
 them as having expended their chief fury some on one part 
 of the coast, some on another. 
 
 But all authentic accounts cease when we ascend to the 
 era of the conquest of Peru by the Spaniards. The ancient 
 Peruvians, although far removed from barbarism, were with- 
 out written annals, and therefore unable to preserve a distinct 
 recollection of a long series of natural events. They had, 
 however, according to Antonio de Herrera, who, in the 
 beginning of the 1 7th century, investigated their antiquities, 
 
 * Ulloa's Voyage to South America, i Wafer, cited by Sir W. Paris]), 
 
 vol. ii. book vii. chap. vii. Greol. Soc. Proceedings, vol. ii. p. 215. 
 
 f Ibid. vol. ii. p. 82. 
 
158 EARTHQUAKE IN JAVA, 1699. [Cn. XXX. 
 
 a tradition, ' that many years before the reign of the Incas, 
 at a time when the country was very populous, there hap- 
 pened a great flood ; the sea breaking out beyond its bounds, 
 so that the land was covered with water and all the people 
 perished. To this the Guacas, inhabiting the vale of Xausca, 
 and the natives of Chiquito, in the province of Callao, add 
 that some persons remained in the hollows and caves of the 
 highest mountains, who again peopled the land. Others of 
 the mountain people affirm that all perished in the deluge, 
 only 6 persons being saved on a float, from whom descended 
 all the inhabitants of that country.' * 
 
 On the mainland near Lima, and on the neighbouring 
 island of San Lorenzo, Mr. Darwin found proofs that the 
 ancient bed of the sea had been raised to the height of more 
 than 80 feet above water within the human epoch, strata 
 having been discovered at that altitude, containing pieces 
 of cotton thread and plaited rush, together with sea-weed 
 and marine shells. f The same author learnt from Mr. Gill, 
 a civil engineer, that he discovered in the interior near Lima, 
 between Casma and Huaraz, the dried-up channel of a large 
 river, sometimes worn through solid rock, which, instead of 
 continually ascending towards its source, has, in one place, 
 a steep downward slope in that direction, for a ridge or line 
 of hills has been uplifted directly across the bed of the stream, 
 which is now arched. By these changes the water has been 
 turned into some other course ; and a district, once fertile, 
 and still covered with ruins, and bearing the marks of 
 ancient cultivation, has been converted into a desert. J 
 
 Java, 1699. On January 5, 1699, a terrible earthquake 
 visited Java, and no less than 208 considerable shocks were 
 reckoned. Many houses in Batavia were overturned, and 
 the flame and noise of a volcanic eruption were seen and 
 heard in that city ? which were afterwards found to proceed 
 from Mount Salek, a volcano 6 days' journey distant. 
 Next morning the Batavian river, which has its rise from 
 that mountain, became very high and muddy, and brought 
 
 * Hist, of America, decad. iii. book J Ibid. p. 413. 
 
 xi. ch. i. Misspelt ' Sales ' in Hooke's Ac- 
 
 f Darwin's Journal, p. 451. count. 
 
CH. XXX.] QUITO, 1698. SICILY, 1693. 150 
 
 down abundance of bushes and trees, half burnt. The 
 channel of the river being stopped up, the water overflowed 
 the country round the gardens about the town, and some of 
 the streets, so that fishes lay dead in them. All the fish in 
 the river, except the carps, were killed by the mud and 
 turbid water. A great number of drowned buffaloes, tigers, 
 rhinoceroses, deer, apes, and other wild beasts, were brought 
 down by the current ; and, c notwithstanding,' observes one 
 of the writers, 'that a crocodile is amphibious, several of 
 them were found dead among the rest.' * 
 
 It is stated that seven hills bounding the river sank down ; 
 by which must be meant, as by similar expressions in the 
 description of the Calabrian earthquakes, seven great land- 
 slips. These hills, descending some from one side of the 
 valley and some from the other, filled the channel, and the 
 waters then finding their way under the mass, flowed out 
 thick and muddy. The Tangaran river was also dammed up 
 by nine hills, and in its channel were large quantities of drift 
 trees. Seven of its tributaries also are said to have been 
 c covered up with earth.' A high tract of forest land, between 
 the two great rivers before mentioned, is described as having 
 been changed into an open country, destitute of trees, the 
 surface being spread over with a fine red clay. This part of 
 the account may, perhaps, merely refer to the sliding down 
 of woody tracts into the valleys, as happened to so many ex- 
 tensive vineyards and olive-grounds, in Calabria, in 1783. 
 The close packing of large trees in the Batavian river is 
 represented as very remarkable, and it attests in a striking 
 manner the destruction of soil bordering the valleys which 
 had been caused by floods and landslips. f 
 
 Quito, 1698. In Quito, on the 19th of July, 1698, during 
 an earthquake, a great part of the crater and summit of the 
 volcano Carguairazo fell in, and a stream of water and mud 
 issued from the broken sides of the hill.J 
 
 Sicily, 1693. Shocks of earthquakes spread over all Sicily 
 in 1693, and on the llth of January the city of Catania 
 and 49 other places were levelled to the ground, and about 
 
 * Hooke's Posthumous Works, p. 437. f Phil. Trans. 1700. 
 
 1705. + Humboldt, Atl. Pit. p. 106. 
 
160 MOLUCCAS, 1693. JAMAICA, 1692. [Cn.XXX. 
 
 100,000 people killed. The bottom of the sea, says Yicentino 
 Bonajutus, sank down considerably, both in ports, inclosed 
 bays, and open parts of the coast, and water bubbled up along 
 the shores. Numerous long fissures of various breadths were 
 caused, which threw out sulphurous water; and one of them, 
 in the plain of Catania (the delta of the Simeto), at the 
 distance of 4 miles from the sea, sent forth water as salt as 
 the sea. The stone buildings of a street in the city of Noto, 
 for the length of half a mile, sank into the ground, and 
 remained hanging on one side. In another street, an opening 
 large enough to swallow a man and horse appeared."* 
 
 Moluccas, 1693. The small Isle of Sorea, which consists 
 of one great volcano, was in eruption in the year 1693. Dif- 
 ferent parts of the cone fell, one after the other, into a deep 
 crater, until almost half the space of the island was converted 
 into a fiery lake. Most of the inhabitants fled to Banda; but 
 great pieces of the mountain continued to fall down, so that 
 the lake of lava became wider ; and finally the whole popula- 
 tion was compelled to emigrate. It is stated that, in pro- 
 portion as the burning lake increased in size, the earthquakes 
 were less vehement.f 
 
 Jamaica, 1692. Subsidence in the harbour. In the year 
 1692, the island of Jamaica was visited by a violent earth- 
 quake; the ground swelled and heaved like a rolling sea, 
 and was traversed by numerous cracks, 200 or 300 of 
 which were often seen at a time, opening and then closing 
 rapidly again. Many people were swallowed up in these 
 rents ; some the earth caught by the middle, and squeezed to 
 death ; the heads of others only appeared above ground ; and 
 some were first engulfed, and then cast up again with great 
 quantities of water. Such was the devastation, that even in 
 Port Eoyal, then the capital, where more houses are said 
 to have been left standing than in the whole island beside, 
 three-quarters of the buildings, together with the ground they 
 stood on, sank down with their inhabitants entirely under 
 water. 
 
 The large store-houses on the harbour side subsided, so as 
 
 * Phil. Trans. 1693-4. f Do la Beche, Manual of Geol., p. 133, 2nd edition. 
 
CH. XXX.] CHANGES CAUSED BY EARTHQUAKES. 161 
 
 to be 24, 36, and 48 feet under water ; yet many of them 
 appear to have remained standing, for it is stated that, after 
 the earthquake, the mast-heads of several ships wrecked in 
 the harbour, together with the chimney-tops of houses, were 
 just seen projecting above the waves. A tract of land round 
 the town, about 1,000 acres in extent, sank down in less than 
 one minute, during the first shock, and the sea immediately 
 rolled in. The Swan frigate, which was repairing in the 
 wharf, was driven over the tops of many buildings, and then 
 thrown upon one of the roofs, through which it broke. The 
 breadth of one of the streets is said to have been doubled by 
 the earthquake. 
 
 According to Sir H. de la Beche, the part of Port Royal 
 described as having sunk was built upon new-formed land, 
 consisting of sand, in which piles had been driven ; and the 
 settlement of this loose sand, charged with the weight of heavy 
 houses, may, he suggests, have given rise to the subsidences 
 alluded to.* 
 
 There have undoubtedly been instances in Calabria and 
 elsewhere of slides of land on which the houses have still 
 remained standing ; and it is possible that such may have 
 been the case at Port Royal. The fact at least of submerg- 
 ence is unquestionable, for I was informed by the late Admiral 
 Sir Charles Hamilton that he frequently saw the submerged 
 houses of Port Royal in the year 1780, in that part of the 
 harbour which lies between the town and the usual anchor- 
 age of men-of-war. Bryan Edwards also says, in his 
 history of the West Indies, that in 1793 the ruins were 
 visible in. clear weather from the boats which sailed over 
 them.f Lastly, Lieutenant B. Jeffery, R.N., told me that, 
 being engaged in a survey between the years 1824 and 1835, 
 he repeatedly visited the site in question, where the depth of 
 the water is from 4 to 6 fathoms, and whenever there was 
 but little wind perceived distinct traces of houses. He saw 
 these more clearly when he used the instrument called the 
 'diver's eye,' which is let down below the ripple of the 
 wave. 
 
 * De la Beche, Manual of GeoL, p. t Vol. i. p. 235, 8vo ed. 3 vols. 1801. 
 
 133, second edition. j Letter to the Author, May 1838. 
 
 VOL. II. M 
 
162 MOUNTAINS SHATTEKED. [On. XXX. 
 
 At several thousand places in Jamaica the earth is related 
 to have opened. On the north of the island, several plan- 
 tations, with their inhabitants, were swallowed up, and a 
 lake appeared in their place, covering above 1,000 acres, 
 which afterwards dried up, leaving nothing but sand and 
 gravel, without the least sign that there had ever been a 
 house or a tree there. Several tenements at Yallows were 
 buried under land-slips ; and one plantation was removed 
 half a mile from its place, the crops continuing to grow 
 upon it uninjured. Between Spanish Town and Sixteen-mile 
 Walk, the high and perpendicular cliffs bounding the river 
 fell in, stopped the passage of the river and flooded the latter 
 place for 9 days, so that the people 6 concluded it had been 
 sunk as Port Royal was.' But the flood at length subsided, 
 for the river had found some new passage at a great distance. 
 
 Mountains shattered. The Blue and other of the highest 
 mountains are declared to have been strangely torn and rent. 
 They appeared shattered and half-naked, no longer affording 
 a fine green prospect, as before, but stripped of their woods 
 and natural verdure. The rivers on these mountains first 
 ceased to flow for about 24 hours, and then brought down 
 into the sea, at Port Royal and other places, several hundred 
 thousand tons of timber, which looked like floating islands 
 on the ocean. The trees were in general barked, most of 
 their branches having been torn off in the descent. It is 
 particularly remarked in this, as in the narratives of so many 
 earthquakes, that fish were taken in great numbers on the 
 coast during the shocks. The correspondents of Sir Hans 
 Sloane, who collected with care the accounts of eye-witnesses 
 of the catastrophe, refer constantly to subsidences, and some 
 supposed the whole of Jamaica to have sunk down.* 
 
 Reflections on the amount of change since the close of the 
 seventeenth century. I have now only enumerated some few of 
 the earthquakes of the last and present centuries, respecting 
 which facts illustrative of geological enquiries are on record. 
 Even if my limits permitted, it would be an unprofitable task 
 to examine all the obscure and ambiguous narratives of 
 
 * Phil. Trans. 1694. 
 
CH. XXX.] KEFLECTIONS ON CHANGES BY EAKTHQUAKES. 163 
 
 similar events of earlier epochs ; although, if the places were 
 now examined by geologists well practised in the art of inter- 
 preting the monuments of physical changes, many events 
 which have happened within the historical era might doubt- 
 less be still determined with precision. It must not be 
 imagined that, in the above sketch of the occurrences of a 
 short period, I have given an account of all, or even the 
 greater part, of the mutations which the earth has under- 
 gone by the agency of subterranean movements. Thus, for 
 example, the earthquake of Aleppo, in the present century, 
 and of Syria, in the middle of the 18th, would doubtless have 
 afforded numerous phenomena, of great geological importance, 
 had those catastrophes been described by scientific observers. 
 The shocks in Syria in 1759 were protracted for three months, 
 throughout a space of 10,000 square leagues : an area com- 
 pared to which that of the Calabrian earthquake in 1783 was 
 insignificant. Accon, Saphat, Balbeck, Damascus, Sidon, 
 Tripoli, and many other places, were almost entirely levelled 
 to the ground. Many thousands of the inhabitants perished 
 in each ; and, in the valley of Balbeck alone, 20,000 men are 
 said to have been victims to the convulsion. In the absence 
 of scientific accounts, it would be as irrelevant to our present 
 purpose to enter into the details of such calamities, as 
 to follow the track of an invading army, to enumerate the 
 cities burnt or razed to the ground, and reckon the number 
 of individuals who perished by famine or sword. 
 
 If such, then, be the amount of ascertained changes in less 
 than two centuries, notwithstanding the extreme deficiency 
 of our records during that brief period, how important must 
 we presume the physical revolutions to have been in the 
 course of 30 or 40 centuries, during which some countries 
 habitually convulsed by earthquakes have been peopled by 
 civilised nations ! Towns engulfed during one earthquake 
 may, by repeated shocks, have sunk to great depths beneath 
 the surface, while the ruins remain as imperishable as the 
 hardest rocks in which they are enclosed. Buildings and 
 cities, submerged, for a time, beneath seas or lakes, and 
 covered with sedimentary deposits, must, in some places, 
 have been re-elevated to considerable heights above the level 
 
 M 2 
 
164 DEFICIENCY OF HISTORICAL RECORDS. [Cn. XXX. 
 
 of the ocean. The signs of these events have, probably, been 
 rendered visible by subsequent mutations, as by the en- 
 croachments of the sea upon the coast, by deep excavations 
 made by torrents and rivers, by the opening of new ravines, 
 and chasms, and other effects of natural agents, so active in 
 districts agitated by subterranean movements. 
 
 If it be asked why, if such wonderful monuments exist, so 
 few have hitherto been brought to light, we reply because 
 they have not been searched for. In order to rescue from 
 oblivion the memorials of former occurrences, the enquirer 
 must know what he may reasonably expect to discover, and 
 under what peculiar local circumstances. He must be ac- 
 quainted with the action and effect of physical causes, in 
 order to recognise, explain, and describe correctly the phe- 
 nomena when they present themselves. 
 
 The best known of the great volcanic regions, of which the 
 boundaries were sketched in Chapter XXII., is that which 
 includes Southern Europe, Northern Africa, and Central Asia; 
 yet nearly the whole, even of this region, must be laid down, 
 in a geological map, as ( Terra Incognita,' for we are only 
 beginning to know something of one small portion of it, viz. 
 the district round Naples ; and even here it is to recent 
 antiquarian and geological research, not to history, that we 
 are principally indebted for the information. I shall now 
 proceed to lay before the reader some of the results of modern 
 investigations in the Bay of Baise and the adjoining coast. 
 
 PROOFS OF ELEVATION AND SUBSIDENCE IN THE BAT OF BAI^E. 
 
 Temple of Jupiter Serapis. This celebrated monument of 
 antiquity, a representation of which is given in the frontis- 
 piece * of this work (Vol. I.), affords in itself alone unequi- 
 vocal evidence that the relative level of land and sea has 
 changed twice at Puzzuoli since the Christian era ; and each 
 
 * The view of the temple given in trate a paper by Mr. Babbage on the 
 
 the frontispiece has been reduced from temple of Serapis, read March, 1834, 
 
 part of a beautiful coloured drawing and published in the Quart. Journ. 
 
 taken in 1836, with the aid of the ca- of the Greol. Soc. of London, vol. iii. 
 
 mera lucida, by Mr. I'Anson, to illus- 1847. 
 
CH. XXX.] BAY OF BAIJE ELEVATION AND SUBSIDENCE. 165 
 
 movement, both of elevation and subsidence, has exceeded 
 20 feet. Before examining these proofs, I may observe, that 
 a geological examination of the coast of the Bay of Baise, both 
 on the north and south of Puzzuoli, establishes in the most 
 
 Fig. 123. 
 
 Ground plan of the coast of the Bay of Baise, in the environs of Puzzuoli. 
 
 satisfactory manner an elevation, at no remote period, of 
 more than 20 feet, and, at one point, of more than 30 feet ; 
 and the evidence of this change would have been complete, 
 even if the temple had, to this day, remained undiscovered. 
 
 Coast south of Puzzuoli. If we coast along the shore from 
 Naples to Puzzuoli, we find, on approaching the latter place, 
 that the lofty and precipitous cliffs of indurated tuff, re- 
 sembling that of which Naples is built, retire slightly from 
 the sea ; and that a low level tract of fertile land, of a very 
 different aspect, intervenes between the present sea-beach 
 and what was evidently the ancient line of coast. 
 
 The inland cliff may be seen opposite the small island of 
 Nisida, about 2-J miles south-east of Puzzuoli (see Map, fig. 
 60, Vol. I. p. 599), where, at the height of 32 feet above the 
 level of the sea, Mr. Babbage observed an ancient mark, 
 such as might have been worn by the waves; and, upon 
 further examination, discovered that, along that line, the 
 face of the perpendicular rock, consisting of very hard tuff, 
 was covered with barnacles (Balanus sulcatus, Lamk.), 
 
166 CHANGES OE LEVEL, PUZZUOLI. [Cir. XXX. 
 
 and drilled by boring testacea. Some of the hollows of the 
 lithodomi contained the shells ; while others were filled with 
 
 the valves of a species of Area.* 
 Nearer to Puzzuoli, the inland cliff 
 
 Fi s- m - sJ&l i g 8 ^ ee ^ h% n ? an ^ as perpen- 
 
 dicular as if it were still under- 
 mined by the waves. At its base, 
 a new deposit, constituting the 
 fertile tract above alluded to, at- 
 tains a height of about 20 feet 
 above the sea ; and since it is 
 com P ose( l f regular sedimentary 
 sub- deposits, containing marine shells, 
 
 marine deposit. ^ g position prOVCS that, Subse- 
 
 quently to its formation, there has been a change of more 
 than 20 feet in the relative level of land and sea. 
 
 The sea encroaches on these new incoherent strata ; and 
 as the soil is valuable, a wall has been built for its protec- 
 tion; but when I first visited the spot in 1828, the waves 
 had swept away part of this rampart, and exposed to view 
 a regular series of strata of tuff, more or less argillaceous, 
 alternating with beds of pumice and lapilli, and containing 
 great abundance of marine shells, of species now common 
 on this coast, and amongst them Cardium rusticum, Ostrea 
 edulisy Donax trunculus, Lamk., and others. The strata vary 
 from about a foot to a foot and a half in thickness, and one 
 of them contains abundantly remains of works of art, tiles, 
 squares of mosaic pavement of different colours, and small 
 sculptured ornaments, perfectly uninjured. Intermixed with 
 these I collected some teeth of the pig and ox. These frag- 
 ments of building occur below as well as above strata con- 
 taining marine shells. Puzzuoli itself stands chiefly on a 
 promontory of the older tufaceous formation, which cuts off 
 the new deposit, although I detected a small patch of the 
 latter in a garden under the town. 
 
 From the town the ruins of a mole, called Caligula's 
 
 * Mr. Babbage examined this spot in rous specimens of the shells collected 
 company with Sir Edmund Head in there, and in the Temple of Serapis. 
 June 1828, and has shown me nume- 
 
CH. XXX.] 
 
 COAST NORTH OF PUZZUOLI. 
 
 167 
 
 Fig. 125. 
 
 Bridge, run out into the sea. (See Plate VII.)* This mole, 
 which is believed to be eighteen centuries old, consists of a 
 number of piers and arches, thirteen of which are now 
 standing, and two others appear to have been overthrown. 
 Mr. Babbage found, on the sixth pier, perforations of litho- 
 domi four feet above the level of the sea; and, near the 
 termination of the mole on the last pier but one, marks of 
 the same, ten feet above the level of the sea, together with 
 great numbers of balani and flustra. The depth of the sea, 
 at a very small distance from most of the piers, is from 30 
 to 50 feet. 
 
 Coast north of Puzzuoli. If we then pass to the north of 
 Puzzuoli, and examine the coast between that town and 
 Monte Nuovo, we find a re- 
 petition of analogous phe- 
 nomena. The sloping sides of 
 Monte Barbaro slant down 
 within a short distance of the 
 coast, and terminate in an 
 inland cliff of moderate ele- 
 vation, to which the geolo- a - Remains of Cicero's villa, N. side of Puz- 
 
 zuoli.f 
 gist perceives at Once that ft. Ancient cliff, now inland. 
 
 c. Terrace (called La Starza) composed of recent 
 the Sea must, at SOme for- submarine deposits. 
 
 mer period, have extended. d - Temple of *""**- 
 Between this cliff and the sea is the low plain or terrace, 
 before alluded to, called La Starza (c, fig. 125), corresponding 
 to that before described on the south-east of the town ; and 
 as the sea encroaches rapidly, fresh sections of the strata may 
 readily be obtained, of which the annexed is an example. 
 Section on the shore north of the town of Puzzuoli : 
 
 Ft. In. 
 
 1. Vegetable soil 10 
 
 2. Horizontal beds of pumice and scoriae, with broken fragments of 
 
 unrolled bricks, bones of animals, and marine shells . . .16 
 
 3. Beds of lapilli, containing abundance of marine shells, principally 
 
 Cardium rusticum, Donax trunculus, Lam., Ostrea edulis, Triton 
 cutaceum, Lam., and Buccinum serratum, Brocchi, the beds varying 
 in thickness from one to eighteen inches . . . ..100 
 
 4. Argillaceous tuff, containing bricks and fragments of buildings not 
 
 rounded by attrition .16 
 
 * This view is taken from Sir W. f This spot here indicated on the 
 
 Hamilton, Campi Phlegrsei, plate 26. summit of the cliff is that from which 
 
168 TEMPLE OF JUPITER SERAPIS. [Cn. XXX. 
 
 The thickness of many of these beds varies greatly as we 
 trace them along the shore, and sometimes the whole group 
 rises to a greater height than at the point above described. 
 The surface of the tract which they compose appears to slope 
 gently upwards towards the base of the old cliffs. 
 
 Now, if such appearances presented themselves on the coast 
 of England, a geologist might endeavour to seek an explana- 
 tion in some local change in the set of the tides and currents : 
 but there are scarcely any tides in the Mediterranean ; and, 
 to suppose the sea to have sunk generally from twenty to 
 twenty-five feet since the shores of Campania were covered 
 with sumptuous buildings, is an hypothesis obviously un- 
 tenable. The observations, indeed, made during modern 
 surveys on the moles and cothons (docks) constructed by the 
 ancients in various ports of the Mediterranean, have proved 
 that there has been no sensible variation of level in that sea 
 during the last two thousand years .* 
 
 Thus we arrive, without the aid of the celebrated temple, at 
 the conclusion, that the recent marine deposit at Puzzuoli 
 was upraised in modern times above the level of the sea, and 
 that not only this change of position, but the accumulation 
 of the modern strata, was posterior to the destruction of 
 many edifices, of which they contain the embedded relics. 
 If we next examine the evidence afforded by the temple 
 itself, it appears, from the most authentic accounts, that the 
 three pillars now standing erect continued, down to the 
 middle of the last century, almost buried in the new marine 
 strata (c, fig. 125). The upper part of each, protruding 
 several feet above the surface was concealed by bushes, and 
 had not attracted, until the year 1749, the notice of anti- 
 quaries; but, when the soil was removed in 1750, they were 
 seen to form part of the remains of a splendid edifice, the 
 pavement of which was still preserved, and upon it lay a 
 number of columns of African breccia and of granite. The 
 original plan of the building could be traced distinctly : 
 it was of a quadrangular form, 70 feet in diameter, and 
 
 Hamilton's view, plate 26, Campi Phle- called the Academia, anciently stood, 
 grsei (reduced in Plate VII.), is taken, * On the authority of the late Ad- 
 
 and on which, he says, Cicero's villa, miral Smyth, R.N. 
 
CH. XXX.] TEMPLE OF JUPITEK SEBAPIS. 169 
 
 the roof had been supported by 46 noble columns, 24 
 of granite, and the rest of marble. The large court was 
 surrounded by apartments, supposed to have been used 
 as bathing-rooms ; for a thermal spring, still used for 
 medicinal purposes, issues just behind the building, and the 
 water of this spring appears to have been originally conveyed 
 by a nlarble duct, still extant, into the chambers, and then 
 across the pavement by a groove an inch or two deep, to a 
 conduit made of Eoman brickwork, by which it gained the sea. 
 Many antiquaries have entered into elaborate discussions 
 as to the deity to which this edifice was consecrated. It is 
 admitted that, among other images found in excavating the 
 ruins, there was one of the god Serapis ; and at Puzzuoli a 
 marble column was dug up, on which was carved an ancient 
 inscription, of the date of the building of Rome 648 (or B.C. 
 105) , entitled ' Lex parieti faciundo.' This inscription, written 
 in very obscure Latin, sets forth a contract, between the 
 municipality of the town, and a company of builders who 
 undertook to keep in repair certain public edifices, the 
 Temple of Serapis being mentioned amongst the rest, and 
 described as being near or towards the sea, ( ad mare vorsum.' 
 Sir Edmund Head, after studying, in 1828, the topography 
 and antiquities of this district, and the Greek, Roman, and 
 Italian writers on the subject, informed me, that at Alex- 
 andria, on the Mle, the chief seat of the worship of Serapis, 
 there was a Serapeum of the same form as this temple at 
 Puzzuoli, and surrounded in like manner by chambers, in 
 which the devotees were accustomed to pass the night, in 
 the hope of receiving during sleep a revelation from the god, 
 as to the nature and cure of their diseases. Hence it was 
 very natural that the priests of Serapis, a pantheistic divinity, 
 who, among other usurpations, had appropriated to himself 
 the attributes of Esculapius, should regard the hot spring as 
 a suitable appendage to the temple, although the original 
 Serapeum of Alexandria could boast no such medicinal waters. 
 Signor Carelli* and others, in objecting to these views, have 
 insisted on the fact, that the worship of Serapis, which we 
 
 * Dissertazione sulla Sagra Archittetura degli Antichi. 
 
170 TEMPLE OF JUPITER SEE APIS. [On. XXX. 
 
 know prevailed at Borne in the clays of Catullus (in the first 
 century before Christ), was prohibited by the Roman Senate, 
 during the reign of the Emperor Tiberius. But there is little 
 doubt that, during the reigns of that Emperor's successors, 
 the shrines of the Egyptian god were again thronged by 
 zealous votaries ; and in no place more so than at Puteoli 
 (now Puzzuoli), one of the principal marts for the produce of 
 Alexandria. 
 
 Without entering farther into an enquiry which is not 
 strictly geological, I shall designate this valuable relic of 
 antiquity by its generally received name, and proceed to 
 consider the memorials of physical changes inscribed on the 
 three standing columns in most legible characters by the 
 hand of Nature. (See Frontispiece, Vol. I.) These pillars, 
 which have been carved each out of a single block of marble, 
 are 40 feet 3 J inches in height. An horizontal fissure nearly 
 intersects one of the columns ; the other two are entire. 
 They are all slightly out of the perpendicular, inclining 
 somewhat to the south-west, that is, towards the sea.* Their 
 surface is smooth and uninjured to the height of about twelve 
 feet above their pedestals. Above this is a zone, about nine 
 feet in height, where the marble has been pierced by a species 
 of marine perforating bivalve Lithodomus, Cuv.f The holes 
 of these animals are pear-shaped, the external opening being 
 minute, and gradually increasing downwards. At the bottom 
 of the cavities, many shells are still found, notwithstanding 
 the great numbers that have been taken out by visitors ; in 
 many the valves of a species of area, an animal which con- 
 ceals .itself in small hollows, occur. The perforations are so 
 considerable in depth and size, that they manifest a long- 
 continued abode of the lithodomi in the columns ; for, as the 
 inhabitant grows older and increases in size, it bores a larger 
 cavity, to correspond with the increased magnitude of its 
 shell. We must, consequently, infer a long-continued im- 
 
 * This appears from the measurement formed out of a single stone was first 
 
 of Captain Basil Hall, K.N., Proceed- pointed out to me by Mr. James Hall, 
 
 ings of Greol. Soc., No. 38, p. 114 ; see and is important, as helping to explain 
 
 also Patchwork, by the same author, why they were not shaken down. 
 
 yol. iii. p. 158. The fact of the three f Modiola lithophaga, Lam. Mytilus 
 
 standing columns having been each lithophagus, Linn. 
 
CH. XXX.] TEMPLE OF JUPITER SEE APIS. 171 
 
 mersion of the pillars in sea-water, at a time when the lower 
 part was covered up and protected by marine, fresh-water, 
 and volcanic strata, afterwards to be described, and by the 
 rubbish of buildings ; the highest part, at the same time, pro- 
 jecting above the waters, and being consequently weathered, 
 but not materially injured. (See fig. 126, p. 172.) 
 
 On the pavement of the temple lie some columns of marble, 
 which are also perforated in certain parts ; one, for example, 
 to the length of 8 feet, while, for the length of 4 feet, it is 
 uninjured. Several of these broken columns are eaten into, 
 not only on the exterior, but on the cross fracture, and, on 
 some of them, other marine animals (serpulse, &c.) have fixed 
 themselves.* All the granite pillars are untouched by litho- 
 domi. The platform of the temple, which is not perfectly 
 even, was, when I visited it in 1828, about one foot below 
 high-water mark (for there are small tides in the Bay of 
 Naples) ; and the sea, which was only 100 feet distant, 
 soaked through the intervening soil. The upper part of the 
 perforations, therefore, was at least 23 feet above high- 
 water mark ; and it is clear that the columns must have 
 continued for a long time in an erect position, immersed in 
 salt water, and then the submerged portion must have been 
 upraised to the height of about 23 feet above the level of 
 the sea. 
 
 By excavations carried on in 1828, below the marble pave- 
 ment on which the columns stand, another costly pavement 
 of mosaic was found, at the depth of about 5 feet below the 
 upper one (a, 6, fig. 126). The existence of these two pave- 
 ments, at different levels, clearly implies some subsidence 
 previously to the building of the more modern temple which 
 had rendered it necessary to construct the new floor at a 
 higher level. 
 
 We have already seen (p. 169) that a temple of Serapis 
 existed long before the Christian era. The change of level 
 just mentioned must have taken place some time before the 
 end of the second century, for inscriptions have been found 
 in the temple, from which we learn that Septimius Severus 
 
 * Scrpula contortuplicata, Linn., and as well as the Lithodomus, are now in- 
 Vermilia triqi'.etra, Lam. These species, habitants of the neighbouring sea. 
 
172 
 
 TEMPLE OF JUPITER SERAPIS. 
 
 [On. XXX. 
 
 adorned its walls with precious marbles, between the years 
 194 and 211 of our era, and the emperor Alexander Severus 
 displayed the like munificence between the years 222 and 
 235.*" From that era there is an entire dearth of historical 
 information for a period of more than twelve centuries, 
 except the significant fact that Alaric and his Goths sacked 
 Puzzuoli in 410, and that Genseric did the like in 445, A.D. 
 Yet we have fortunately a series of natural archives self- 
 registered during the dark ages, by which many events which 
 occurred in and about the temple are revealed to us. These 
 natural records consist partly of deposits, which envelop the 
 pillars below the zone of lithodomous perforations, and 
 partly of those which surround the outer walls of the temple. 
 Mr. Babbage, after a minute examination of these, has shown 
 (see p. 164, note) that incrustations on the walls of the 
 
 A 
 
 Fig. 126. 
 
 Sea 
 
 Temple of Serapis at its period of greatest depression. 
 
 a 6. Ancient mosaic pavement. 
 c c. Dark marine incrustation. 
 d d. First filling up, shower of ashes. 
 
 e e. Freshwater calcareous deposit. 
 //. Second filling up. 
 A. Stadium. 
 
 exterior chambers and on the floor of the building demon- 
 strate that the pavement did not sink down suddenly, but 
 was depressed by a gradual movement. The sea first entered 
 the court or atrium, and mingled its waters partially with 
 those of the hot spring. From this brackish medium a dark 
 calcareous precipitate (c c, fig. 126) was thrown down, which 
 became, in the course of time, more than two feet thick, 
 including some serpulse in it. The presence of these annelids 
 teaches us that the water was salt or brackish. After this 
 period the temple was filled up with an irregular mass of 
 volcanic tuff (d d, fig. 126), probably derived from an erup- 
 tion of the neighbouring crater of the Solfatara, to the 
 
 fc * Brieslak, Voy. dans la Campanie, torn. ii. p. 167. 
 
CH. XXX.] TEMPLE OF JUPITER SERAPIS. 173 
 
 height of from 5 to 9 feet above the pavement. Over this 
 again a purely freshwater deposit of carbonate of lime (e e, 
 fig. 126) accumulated with an uneven bottom, since it neces- 
 sarily accommodated itself to the irregular outline of the 
 upper surface of the volcanic shower before thrown down. 
 The top of the same deposit (a freshwater limestone) was 
 perfectly even and flat, bespeaking an ancient water level. 
 It is suggested by Mr. Babbage that this freshwater lake 
 may have been caused by the fall of ashes which choked up 
 the channel previously conynunicating with the sea, so that 
 the hot spring threw down calcareous matter in the atrium 
 without any marine intermixture. To the freshwater lime- 
 stone succeeded another irregular mass of volcanic ashes and 
 rubbish (//, fig. 126), some of it perhaps washed in by the 
 waves of the sea during a storm, its surface rising to 10 or 
 11 feet above the pavement. And thus we arrive at the 
 period of greatest depression expressed in the accompanying 
 diagram, when the lower half of the pillars was enveloped 
 in the deposits above enumerated, and the uppermost 20 feet 
 were exposed in the atmosphere, the remaining or middle 
 portion, about 9 feet long, being for years immersed in salt 
 water and drilled by perforating bivalves. After this period 
 other strata, consisting of showers of volcanic ashes and 
 materials washed in during storms, covered up the pillars to 
 the height in some places of 35 feet above the pavement. 
 The exact time when these enveloping masses were heaped 
 up, and how much of them were formed during submergence, 
 and how much after the re-elevation of the temple, cannot 
 be made out with certainty. 
 
 The period of deep submergence was certainly antecedent 
 to the close of the loth century. Professor James Forbes* 
 has reminded us of a passage in an old Italian writer, 
 Loffredo, who says that in 1530, or 50 years before he wrote, 
 which was in 1580, the sea washed the base of the hills 
 which rise from the flat land called La Starza, as represented 
 in fig. 126; so that, to quote his words, c a person might 
 then have fished from the site of those ruins which are now 
 caUed the stadium' (A, fig. 126). 
 
 * Ed. Journ. of Science, new series, No. II. p. 281. 
 
174 TEMPLE OF JUPITER SERAPIS. [On. XXX. 
 
 But we know from other evidence that the upward move- 
 ment had begun before 1530, for the Canonico Andrea di Jorio 
 cites two authentic documents in illustration of this point. 
 The first, dated Oct. 1503, is a deed written in Italian, by 
 which Ferdinand and Isabella grant to the University of 
 Puzzuoli a portion of land, ' where the sea is drying up ' 
 (che va seccando el mare) ; the second, a document in Latin, 
 dated May 23, 1511, or nearly 8 years after, by which 
 Ferdinand grants to the city a certain territory around 
 Puzzuoli, where the ground is dried up (desiccatum) .* 
 
 The principal elevation, however, of the low tract un- 
 questionably took place at the time of the great eruption of 
 Monte Nuovo in 1538. That event and the earthquakes 
 which preceded it have been already described (Yol. I. 
 p. 609) ; and we have seen that two of the eye-witnesses of 
 the convulsion, Falconi and Giacomo di Toledo, agree in 
 declaring that the sea abandoned a considerable tract of the 
 shore, so that fish were taken by the inhabitants ; and, 
 among other things, Falconi mentions that he saw two springs 
 in the newly discovered ruins. 
 
 The flat land, when first upraised, must have been more 
 extensive than now, for the sea encroaches somewhat rapidly, 
 both to the north and south-east of Puzzuoli. The coast 
 had, when I examined it in 1828, given way more than a 
 foot in a twelvemonth ; and I was assured, by fishermen in 
 the bay, that it has lost ground near Puzzuoli, to the extent 
 of 30 feet, within their memory. 
 
 It is, moreover, very probable that the land rose to a 
 greater height at first, before it ceased to move upwards, than 
 the level at which it was observed to stand when the temple 
 was re-discovered in 1749, for we learn from a memoir of 
 Niccolini, published in 1838, that since the beginning of the 
 19th century, the temple of Serapis has subsided more than 
 2 feet. That learned architect visited the ruins frequently, 
 for the sake of making drawings, in the beginning of the 
 year 1807, and was in the habit of remaining there through- 
 out the day, yet never saw the pavement overflowed by the 
 
 * Sul Tempio di Serap. ch. viii. 
 
CH. XXX.] TEMPLE OF JUPITER SERAPIS. 175 
 
 sea, except occasionally when the south wind blew violently. 
 On his return, 16 years after, to superintend some exca- 
 vations ordered by the King of Naples, he found the 
 pavement covered by sea-water twice every day at high tide, 
 so that he was obliged to place there a line of stones to stand 
 upon. This induced him to make a series of observations 
 from Oct. 1822 to July 1838, by which means he ascertained 
 that the ground had been and was sinking, at the average 
 rate of about 7 millimetres a year, or about 1 inch in 4 years ; 
 so that, in 1838, fish were caught every day on that part of 
 the pavement where, in 1807, there was never a drop of 
 water in calm weather.* 
 
 Mr. Smith, of Jordan Hill, examined the temple in 1847, 
 and came to the conclusion from a comparison of various data 
 that the rate of subsidence at that period was one inch 
 annually.f Signor Scacchi, in 1852, after an examination 
 undertaken by him at my request, inferred that the down- 
 ward movement had ceased for several years, or had at least 
 become almost inappreciable. I made several observations 
 in 1857 and 1858, and came to the conclusion that there was 
 a depth of about 2 feet of water on the pavement near the 
 bronze ring on calm days at high tide when the Bay of Baise 
 was not raised above its ordinary level by the wind. Although 
 it would require a long series of measurements to obtain the 
 exact average height of the tide in the bay, I cannot doubt 
 that the relative level of the pavement and the sea has 
 altered very sensibly since Niccolini first frequented the 
 place. 
 
 From what was said before (p. 167), we saw that the 
 marine shells in the strata forming the plain called La 
 Starza, considered separately, establish the fact of an up- 
 heaval of the ground to the height of 23 feet and upwards. 
 The temple proves much more, because it could not have 
 been built originally under water, and must therefore first 
 have sunk down 20 feet at least below the waves, to be 
 afterwards restored to its original position. Yet if such was 
 the order of events, we ought to meet with other independent 
 
 * Tavola Metrica Chronologica, &c. f Quart. Journ. G-eol. Soc. vol. iii. 
 
 Napoli, 1838. p. 237. 
 
176 ROMAN ROADS UNDER WATER. [Cn. XXX. 
 
 signs of a like subsidence round the margin of a bay once so 
 studded with buildings as the Bay of Baise. Accordingly, 
 memorials of such submergence are not wanting. About a 
 mile NW. of the temple of Serapis, and about 500 feet 
 from the shore, are the ruins of a temple of Neptune and 
 others of a temple of the Nymphs, now under water. The 
 columns of the former edifice stand erect in five feet water, 
 their upper portions just rising to the surface of the sea. 
 The pedestals are doubtless buried in the sand or mud ; so 
 that, if this part of the bottom of the bay should hereafter 
 be elevated, the exhumation of these temples might take 
 place after the manner of that of Serapis. Both these 
 buildings probably participated in the movement which 
 raised the Starza ; but either they were deeper under water 
 than the temple of Serapis, or they were not raised up again 
 to so great a height. There are also two Roman roads under 
 water in the bay, one reaching from Puzzuoli to the Lucrine 
 Lake, which may still be seen, and the other near the castle of 
 Baise (No. 8, Plate VII. page 167). The ancient mole, too, of 
 Puzzuoli (No. 4, ibid.), before alluded to, has the water up to 
 a considerable height of the arches ; whereas Brieslak justly 
 observes, it is next to certain that the piers must formerly 
 have reached the surface before the springing of the arches;* 
 so that, although the phenomena before described prove that 
 this mole has been uplifted 10 feet above the level at which 
 it once stood, it is still evident that it has not yet been 
 restored to its original position. 
 
 A modern writer also reminds us, that these effects are not 
 so local as some would have us to believe ; for on the opposite 
 side of the Bay of Naples, on the Sorrentine coast, which, 
 as well as Puzzuoli, is subject to earthquakes, a road, with 
 fragments of Roman buildings, is covered to some depth by 
 the sea. In the island of Capri, also, which is situated some 
 way out at sea, in the opening of the Bay of Naples, one of 
 the palaces of Tiberius is now covered with water, f 
 
 * Voy. dans la Campanie, tome ii. 1829. When I visited Puzzuoli, and 
 
 p. 1 62. arrived at the above conclusions, I knew 
 
 t Mr. Forbes, Physical Notices of the nothing of Mr. Forbes's observations, 
 
 Bay of Naples. Ed. Journ. of Sci., which I first saw on my return to Eng- 
 
 No. II., new series, p. 280. October land the year following. 
 
CH. XXX.] HEAT THE CAUSE OF CHANGE OF LEVEL. 177 
 
 That buildings should have been submerged, and afterwards 
 upheaved, without being entirely reduced to a heap of ruins, 
 will appear no anomaly, when we recollect that, in the year 
 1819, when the delta of the Indus sank down, the houses 
 within the fort of Sindree subsided beneath the waves 
 without being overthrown. In like manner, in the year 1692, 
 the buildings around the harbour of Port Eoyal, in Jamaica, 
 descended suddenly to the depth of between 30 and 50 feet 
 under the sea without falling. Even on small portions of 
 land transported to a distance of a mile down a declivity, 
 tenements, like those near Mileto, in Calabria, were carried 
 entire. At Valparaiso buildings were left standing in 1822, 
 when their foundations, together with a long tract of the 
 Chilian coast, were permanently upraised to the height of 
 several feet. It is still more easy to conceive that an edifice 
 may escape falling during the upheaval or subsidence of land, 
 if the walls are supported on the exterior and interior with a 
 deposit like that which surrounded and filled to the height 
 of 10 or 11 feet the temple of Serapis all the time it was 
 sinking, and which enveloped it to more than twice that 
 height when it was rising again to its original level. 
 
 We can scarcely avoid the conclusion, as Mr. Babbage has 
 hinted, 6 that the action of heat is in some way or other the 
 cause of the phenomena of the change of level of the temple. 
 Its own hot spring, its immediate contiguity to the Solfatara, 
 its nearness to the Monte Nuovo, the hot spring at the baths 
 of Nero (No. 6, Plate VII.) , on the opposite side of the Bay 
 of Baiso ; the boiling springs and ancient volcanos of Ischia 
 on one side and Vesuvius on the other, are the most prominent 
 of a multitude of facts which point to that conclusion.'* And 
 when we reflect on the dates of the principal oscillations of 
 level, and the volcanic history of the country before described 
 (Chapter XXIV.), we seem to discover a connection between 
 each era of upheaval and a local development of volcanic- 
 heat, and again between each era of depression and the local 
 quiescence or dormant condition of the subterranean igneous 
 causes. Thus, for example, before the Christian era, when so 
 many vents were in frequent eruption in. Ischia, and when 
 
 * Quart. Journ. G-eol. Soc. 1847, vol. iii. p. 203. 
 VOL. II. N 
 
178 PERMANENCE OF THE OCEAN'S LEVEL. [Cn. XXX. 
 
 A.vernus and other points in the Phlegrsean Fields were 
 celebrated for their volcanic aspect and character, the ground 
 on which the temple stood was several feet above water. 
 Vesuvius was then regarded as a spent volcano ; but when, 
 after the Christian era, the fires of that mountain were 
 rekindled, scarcely a single outburst was ever witnessed in 
 Ischia, or around the Bay of Baise. Then the temple was 
 sinking. Vesuvius, at a subsequent period, became nearly 
 dormant for five centuries preceding the great outbreak of 
 1631 (see Vol. I. p. 618), and in that interval the Solfatara was 
 in eruption A.D. 1198, Ischia in 1302, and Monte Nuovo was 
 formed in 1538. Then the foundations on which the temple 
 stood were rising again. Lastly, Vesuvius once more became 
 a most active vent, and has been so ever since, and during 
 the same lapse of time the area of the temple, so far as we 
 know anything of its history, has been subsiding. 
 
 These phenomena would agree well with the hypothesis, 
 that when the subterranean heat is on the increase, and 
 when lava is forming without obtaining an easy vent, like 
 that afforded by a great habitual chimney, such as Vesuvius, 
 the incumbent surface is uplifted ; but when the heated rocks 
 below are cooling and contracting, and sheets of lava are 
 slowly consolidating and diminishing in volume, then the 
 incumbent land subsides. 
 
 Signor Niccolini, when he ascertained in 1838 that the 
 relative levels of the floor of the temple and of the sea were 
 slowly changing from year to year, embraced the opinion 
 that it was the sea which was rising. But Signor Capocci 
 successfully controverted this view, appealing to many ap- 
 pearances which attest the local character of the movements 
 of the adjoining country, besides the historical fact that in 
 1538, when the sea retired permanently 200 yards from 
 the ancient shore at Puzzuoli, there was no simultaneous 
 retreat of the waters from Naples, Castelamare, and Ischia.^ 
 
 Permanence of the ocean's level. In concluding this subject, 
 I may observe, that the interminable controversies to which 
 the phenomena of the Bay of Baise gave rise, have sprung 
 from an extreme reluctance to admit that the land, rather 
 
 * Nuove Eicerche sul Temp, di Scrap. 
 
CH. XXX.] PERMANENCE OF THE OCEAN'S LEVEL. 179 
 
 than the sea, is subject alternately to rise and fall. Had it 
 been assumed, as most probable, that the level of the ocean 
 was invariable, on the ground that no fluctuations have as 
 yet been clearly established, and that, on the other hand, the 
 continents are inconstant in their level, as has been de- 
 monstrated by the most unequivocal proofs again and again, 
 from the time of Strabo to our own times, the appearances 
 of the temple at Puzzuoli could never have been regarded 
 as enigmatical. Even if contemporary accounts had not 
 distinctly attested the upraising of the coast, this explanation 
 should have been proposed in the first instance as the most 
 natural, instead of being now adopted unwillingly when all 
 others have failed. 
 
 To the strong prejudices still existing in regard to the 
 mobility of the land, we may attribute the rarity of such 
 discoveries as have been recently brought to light in New 
 Zealand, the Bay of Baise, and the Bay of Conception. A 
 false theory, it is well known, may render us blind to facts, 
 which are opposed to our prepossessions, or may conceal 
 from us their true import when we behold them. But it is 
 time that the geologist should, in some degree, overcome 
 those first and natural impressions which induced the poets 
 of old to select the rock as the emblem of firmness the sea 
 as the image of inconstancy. Our modern poet, in a more 
 philosophical spirit, saw in the sea ' the image of eternity,' 
 and has finely contrasted the fleeting existence of the suc- 
 cessive empires which have flourished and fallen on the 
 borders of the ocean with its own unchanged stability. 
 
 Their decay 
 
 Has dried up realms to deserts : not so thou, 
 
 Unchangeable, save to thy wild waves' play : 
 
 Time writes no wrinkle on thine azure brow ; 
 
 Such as creation's dawn beheld, thou rollest now. 
 
 CHILDE HAROLD, Canto iv. 
 
 N 2 
 
180 
 
 CHAPTER XXXI. 
 
 ELEVATION AND SUBSIDENCE OF LAND WITHOUT EARTHQUAKES. 
 
 CHANGES IN THE RELATIVE LEVEL OF LAND AND SEA IN REGIONS NOT 
 VOLCANIC OPINION OF CELSIUS THAT THE WATERS OF THE BALTIC SEA AND 
 
 NORTHERN OCEAN WERE SINKING OBJECTIONS RAISED TO HIS OPINION 
 
 PROOFS OF THE STABILITY OF THE SEA LEVEL IN THE BALTIC PLAYFAIR'S 
 HYPOTHESIS THAT THE LAND WAS RISING IN SWEDEN OPINION OF VON BUCK 
 MARKS CUT ON THE ROCKS SURVEY OF THESE IN 1820 SIGNS OF OSCILLA- 
 TIONS IN LEVEL FISHING HUT BURIED UNDER MARINE STRATA FACILITY OF 
 
 APPRECIATING SLIGHT ALTERATIONS OF LEVEL ON THE INNER AND OUTER COAST 
 
 OF SWEDEN SUPPOSED MOVEMENT IN OPPOSITE DIRECTIONS IN PROCEEDING 
 
 FROM THE NORTH CAPE SOUTHWARDS TO SCANIA CHANGE OF LEVEL ON THE 
 WEST COAST NEAR GOTHENBURG GEOLOGICAL PROOFS OF THE GREAT OSCILLA- 
 TION OF LEVEL SINCE THE GLACIAL PERIOD AT UDDEVALLA UPRAISED MARINE 
 DEPOSITS OF THE WESTERN COAST OF SWEDEN CONTAINING SHELLS OF THE 
 OCEAN, THOSE ON THE EASTERN COAST SHELLS OF THE BALTIC -WHETHER 
 
 NORWAY IS NOW RISING MODERN SUBSIDENCE IN PART OF GREENLAND 
 
 PROOFS AFFORDED BY THESE MOVEMENTS OF GREAT SUBTERRANEAN CHANGES. 
 
 WE have now considered the phenomena of volcanos and 
 earthquakes according to the division of the subject before 
 proposed (Vol. I. p. 577), and have next to turn our attention to 
 those slow and insensible changes in the relative level of land 
 and sea which take place in countries remote from volcanos, 
 and where no violent earthquakes have occurred within the 
 period of human observation. Early in the last century the 
 Swedish naturalist, Celsius, expressed his opinion that the 
 waters, both of the Baltic and Northern Ocean, were gradually 
 subsiding. Prom numerous observations, he inferred that the 
 rate of depression was about 40 Swedish inches in a century.* 
 In support of this position, he alleged that there were many 
 rocks both on the shores of the Baltic and the ocean known 
 to have been once sunken reefs, and dangerous to navigators, 
 
 * The Swedish measure scarcely dif- into twelve inches, and being less than 
 fers from ours ; the foot being divided ours by three-eighths of an inch only. 
 
CH. XXXI.] RISE OF LAND IN SWEDEN. 181 
 
 but which were in his time above water that the waters of 
 the Gulf of Bothnia had been gradually converted into land, 
 several ancient ports having been changed into inland cities, 
 small islands joined to the continent, and old fishing grounds 
 deserted as being too shallow, or entirely dried up. Celsius 
 also maintained, that the evidence of the change rested not 
 only on modern observations, but on the authority of the 
 ancient geographers, who had stated that Scandinavia was 
 formerly a,n island. This island, he argued, must in the 
 course of centuries, by the gradual retreat of the sea, have 
 become connected with the continent; an event which he 
 supposed to have happened after the time of Pliny, and 
 before the ninth century of our era. 
 
 To this argument it was objected that the ancients were 
 so ignorant of the geography of the most northern parts of 
 Europe, that their authority was entitled to no weight ; and 
 that their representation of Scandinavia as an island, might 
 with more propriety be adduced to prove the scantiness of 
 their information, than to confirm so bold an hypothesis. It 
 was also remarked, that if the land which connected Scandi- 
 navia with the main continent was laid dry between the time 
 of Pliny and the 9th century, to the extent to which it is 
 known to have risen above the sea at the latter period, the 
 rate of depression could not have been uniform, as was pre- 
 tended ; for it ought to have fallen much more rapidly between 
 the 9th and 18th centuries. 
 
 Many of the proofs relied on by Celsius and his followers 
 were immediately controverted by several philosophers, who 
 saw clearly that a fall of the sea in any one region could not 
 take place without a general sinking of the waters over the 
 whole globe ; they denied that this was the fact, or that the 
 depression was universal, even in the Baltic. In proof of the 
 stability of the level of that sea, they appealed to the position 
 of the island of Saltholm, not far from Copenhagen. This 
 island is so low, that in autumn and winter it is perma- 
 nently overflowed ; and it is only dry in summer, when it 
 serves for pasturing cattle. It appears, from the documents 
 of the year 1280, that Saltholm was then also in the same 
 state, and exactly on a level with the mean height of the sea, 
 
182 EISE OF LAND IN SWEDEN. [Cn. XXXI. 
 
 instead of having been about 20 feet under water, as it ought 
 to have been, according to the computation of Celsius. Several 
 towns, also, on the shores of the Baltic, as Lubeck, Wismar, 
 Bostock, Stralsund, and others, after 600 and even 800 years, 
 are as little elevated above the sea as at the era of their 
 foundation, being now close to the water's edge. The lowest 
 part of Dantzic was no higher than the mean level of the 
 sea in the year 1000 ; and after 8 centuries its relative posi- 
 tion remains exactly the same.* 
 
 Several of the examples of the gain of land and shallowing 
 of the sea pointed out by Celsius, and afterwards by Linnseus, 
 who embraced the same opinions, were ascribed by others to 
 the deposition of sediment at points where rivers entered; 
 and, undoubtedly, Celsius had not sufficiently distinguished 
 between changes due to these causes and such as would arise 
 if the waters of the ocean itself were diminishing. Many 
 large rivers descending from a mountainous country, at the 
 head of the Gulf of Bothnia, enter the sea charged with sand, 
 mud, and pebbles ; and it was said that in these places the 
 low land had advanced rapidly, especially near Torneo. At 
 Piteo also, ^ a mile had been gained in 45 years ; at Luleo,f 
 no less than 1 mile in 28 years ; facts which might all be 
 admitted consistently with the assumption that the level of 
 the Baltic has remained unchanged, like that of the Adriatic, 
 during a period when the plains of the Po and the Adige have 
 greatly extended their area. 
 
 It was also alleged that certain insular rocks, once entirely 
 covered with water, had at length protruded themselves above 
 the waves, and grown, in the course of a century and a half, 
 to be 8 feet high. The following attempt was made to ex- 
 plain away this phenomenon : In the Baltic, large erratic 
 blocks, as well as sand and smaller stones which lie on shoals, 
 are liable every year to be frozen into the ice, where the sea 
 freezes to the depth of 5 or 6 feet. On the melting of the 
 snow in spring, when the sea rises about J a fathom, numerous 
 
 * For a full account of the Celsian f Pitio and Luleo are spelt, in many 
 
 controversy, we may refer our readers English maps, Pitea and Lulea, but the 
 
 to Von Hoff, G-eschichte, &c. vol. i. a is not sounded in the Swedish diph- 
 
 p. 439. thong a. 
 
CH. XXXI.] KISE OF LAND IN SWEDEN. 183 
 
 ice-islands float away, bearing up these rocky fragments so 
 as to convey them to a distance ; and if they are driven by 
 the waves upon shoals, they may convert them into islands 
 by depositing the blocks ; if stranded upon low islands, they 
 may considerably augment their height. 
 
 Browallius, also, and some other Swedish naturalists, 
 affirmed that some islands were lower than formerly ; and 
 that, by reference to this kind of evidence, there was equally 
 good reason for contending that the level of the Baltic was 
 gradually rising. They also added another curious proof of 
 the permanency of the water level, at some points at least, 
 for many centuries. On the Finland coast were some large 
 pines and oaks, growing close to the water's edge; these 
 were cut down, and, by counting the concentric rings of 
 annual growth, as seen in a transverse section of the trunk, 
 it was demonstrated that some of them had stood there 
 for nearly 400 years. Now, according to the Celsian hypo- 
 thesis, the sea had sunk about 15 feet during that period, in 
 which case the germination and early growth of these trees 
 must have been, for many seasons, below the level of the 
 water. In like manner, it was asserted that the lower walls 
 of many ancient castles, such as those of Sonderburg and 
 Abo, reached then to the water's edge, and must, therefore, 
 according to the theory of Celsius, have been originally con- 
 structed below the level of the sea. 
 
 In reply to this last argument, Colonel Hallstrom, a 
 Swedish engineer, well acquainted with the Finland coast, 
 assured me, that the base of the walls of the castle of Abo is 
 now ten feet above the water, so that there may have been a 
 considerable rise of the land at that point since the building 
 was erected. But the argument founded on the position of 
 the trees is, as Professors Loven and Erdmann have lately 
 remarked, unanswerable so far as it relates to a part at least 
 of the Finnish coast. 
 
 Playfair, in his f Illustrations of the Huttonian Theory,' 
 in 1802, admitted the sufficiency of the proofs adduced by 
 Celsius, but attributed the change of level to the movement 
 of the land, rather than to a diminution of the waters. He 
 observed, ' that in order to depress or elevate the absolute 
 
184 
 
 RISE OF LAND JN SWEDEN. [Cn. XXXI. 
 
 Fig. 127. 
 
 BJ 
 
 level of the sea, by a given quantity, in any one place, we 
 must depress or elevate it by the same quantity over the 
 whole surface of the earth ; whereas no such necessity exists 
 
CH. XXXI.] KISE OF LAND IN SWEDEN. 185 
 
 with respect to the elevation or depression of the land.'* 
 The hypothesis of the rising of the land, he adds, 6 agrees 
 well with the Huttonian theory, which holds that our conti- 
 nents are subject to be acted upon by the expansive forces 
 of the mineral regions ; that by these forces they have been 
 actually raised up, and are sustained by them in their pre- 
 sent situation, 'f 
 
 In the year 1807, Yon Buch, after returning from a tour 
 in Scandinavia, announced his conviction, 'that the whole 
 country, from Frederickshall in Norway to Abo in Finland, 
 and perhaps as far as St. Petersburg, was slowly and in- 
 sensibly rising.' He also suggested 'that Sweden may 
 rise more than Norway, and the northern more than the 
 southern part.' { He was led to these conclusions principally 
 by information obtained from the inhabitants and pilots 
 respecting marks which had been set on the rocks, and 
 partly by the occurrence of marine shells of recent species, 
 which he had found at several points on the coast of Norway 
 above the level of the sea. Von Buch, therefore, has the 
 merit of being the first geologist who, after a personal ex- 
 amination of the evidence, declared in favour of the rise of 
 land in Scandinavia. 
 
 The attention excited by this subject in the early part, of 
 the last century, had induced many philosophers in Sweden 
 to endeavour to determine, by accurate observations, whether 
 the standard level of the Baltic was really subject to peri- 
 odical variations ; and under their direction, lines or grooves, 
 indicating the ordinary level of the water on a calm day, 
 together with the date of the year, were chiselled out upon 
 the rocks. In 1820-21, all the marks made before those 
 years were examined by the officers of the pilotage establish- 
 ment of Sweden ; and in their report to the Eoyal Academy 
 of Stockholm they declared, that on comparing the level of 
 the sea at the time of their observations with that indicated 
 by the ancient marks, they found that the Baltic was lower 
 relatively to the land in certain places, but the amount of 
 change during equal periods of time had not been everywhere 
 
 * Sect, 393. f Sect. 398. 
 
186 KISE OF LAND IN SWEDEN. [On. XXXI. 
 
 the same. During their survey, they cut new marks for 
 the guidance of future observers, several of which I had 
 an opportunity of examining fourteen years after (in the 
 summer of 1834), and in that interval the land appeared to 
 me to have risen at certain places north of Stockholm, as 
 near Gefle, for example, about 4 inches, or at the rate of less 
 than 2^ feet per century. But at Stockholm, I inferred from 
 the position of certain aged oak-trees only 8 feet above the 
 level of the Baltic, that the rise could not have been at a 
 greater rate than 10 inches in a century, and might be less.* 
 Professor Axel Erdmann in 1847 calculated that the rise could 
 hardly have exceeded six inches at Stockholm, and in the 
 same year he pointed out, in a paper read to the Royal 
 Society of Sweden, the necessity of determining the mean 
 level of the Baltic by a long series of observations in dif- 
 ferent seasons of the year. Mr. Wolfstedt, a Swedish en- 
 gineer, has shown that the northern part of the Bothnian 
 Gulf, where several great rivers enter, is 16 feet higher than 
 the southern part ; but as this gulf is about 600 miles in 
 length, it will be seen that the rate of fall per mile accord- 
 ing to this measurement is exceedingly small, so that the 
 height of the water at corresponding seasons may vary but 
 slightly, except when it is influenced by the wind. When I 
 gave the results of my Swedish tour in the fourth edition 
 of this work, published in 1835, I expressed my belief that 
 there were signs of the upheaval of the land in different 
 places visited by me, both on the coast of the Bothnian 
 Gulf and on that of the ocean, i. e. the west coast of Sweden 
 near Gothenburg. But I then stated that 'we have not only 
 to learn whether the motion proceeds always at the same rate, 
 but also whether it has been uniformly in one direction. The 
 level of the land may oscillate ; and for centuries there 
 may be a depression, and afterwards a re-elevation, of the 
 same district. Some phenomena in the neighbourhood of 
 Stockholm appear to me only explicable on the supposi- 
 tion of the alternate rising and sinking of the ground 
 
 * See a paper on 'Else of Land in 1835, part i. p. 13 read in November 
 Sweden,' by the author. Phil. Trans. 1834. 
 
CH. XXXI.] KISE OF LAND IN SWEDEN. 187 
 
 since the country was inhabited by man. In digging- a 
 canal, in 1819, at Sodertelje, about sixteen miles to the 
 south of Stockholm, to unite Lake Maeler with the Baltic, 
 marine strata, containing fossil shells of Baltic species, were 
 passed through. At a depth of about 60 feet, they came 
 down upon what seems to have been a buried fishing-hut, 
 constructed of wood in a state of decomposition, which soon 
 crumbled away on exposure to the air. The lowest part, 
 however, which had stood on a level with the sea, was in a 
 more perfect state of preservation. On the floor of this hut 
 was a rude fireplace, consisting of a ring of stones, and 
 within these were cinders and charred wood. On the out- 
 side lay boughs of the fir, cut as with an axe, with the 
 leaves or needles still attached. It seems impossible to 
 explain the position of this buried hut, without imagining, 
 first, a subsidence to the depth of more than 60 feet, then a 
 re-elevation. During the period of submergence, the hut 
 must have become covered over with gravel and shelly marl, 
 under which not only the hut, but several vessels also were 
 found, of a very antique form, and having their timbers 
 fastened together by wooden pegs instead of nails.' * 
 
 The investigations of MM. Loven, Erdmann, Norden- 
 skiold, and others, made since my visit to Sweden in 1834, 
 have on the whole tended to confirm the idea previously 
 entertained, that some changes are now going on in the 
 relative level of land and sea in certain parts of the Swedish 
 coast, but they incline to the opinion that they are local. 
 With a view of accurately determining the reality of the 
 movement, and its amount and direction, they have insti- 
 tuted a regular series of annual observations, which, how- 
 ever, have not yet been continued long enough to lead to 
 positive results. 
 
 Lord Selkirk in 1866 re-examined many of the marks 
 which I had seen, both in the Gulf of Bothnia and on the 
 
 * See my paper, before referred to, come filled up in time by sand drifted 
 Phil. Trans. 1835, part i. pp. 8, 9. At- by the wind. The engineers who super- 
 tempts have, been since made to explain intended the works in 1819, and with 
 away the position of this hut, by con- whom I conversed, had considered every 
 jecturing that a more ancient trench had hypothesis of the kind, but could not so 
 been previously dug here, which had be- explain the facts. 
 
188 EISE OF LAND IN SWEDEN. [Cn. XXXI. 
 
 Swedish coast near Gothenburg, in 1834. Among the former, 
 the principal one, that of Lofgrund, near Gefle, seemed to in- 
 dicate a fall of the water of about 9 inches in 32 years, which 
 would give a rise of the land of between 2 and 3 feet in a 
 century, as I had suggested; but other marks in the neighbour- 
 hood implied a smaller change of level. A line which I myself 
 cut on a rock in the island of Gulholmen, off Oregrund, on 
 the west coast, was found to be only 3 inches higher above 
 the sea-level than when I made it. On the whole, after a com- 
 parison of this and various other marks, Lord Selkirk came to 
 the conclusion, that, notwithstanding the absence of lunar 
 tides both in the Baltic and on the west coast of Sweden 
 near Gothenburg, there is so much fluctuation in the sea- 
 level from day to day, owing to the action of the wind and 
 other causes, that the observations of a casual visitor are 
 of no real value in determining the average water-level.* 
 
 After a review of all that has been said and published on 
 this subject since the commencement of the present century, 
 I am inclined to believe, with the pilots, fishermen, and 
 engineers, that a slow alteration in the relative level of land 
 and sea is taking place along certain parts of the Swedish 
 coast. This notion is not merely entertained by the inha- 
 bitants of those localities where rivers are carrying down 
 sediment into the sea, but prevails equally in districts where 
 the rocks for hundreds of miles plunge abruptly into deep 
 water. It should be borne in mind, that, except near the 
 Cattegat, there are no tides in the Gulf of Bothnia. It is 
 only when particular winds have prevailed for several days 
 in succession, or at certain seasons when there has been an 
 unusually abundant influx of river-water, or when these 
 causes have combined, that this sea is made to rise 2 or 3 
 feet above its standard level. 
 
 There are, moreover, peculiarities in the configuration of 
 the shore which facilitate, in a remarkable degree, the appre- 
 ciation of slight changes in the relative level of land and 
 water. It has often been said, that there are two coasts, 
 
 * Lord Selkirk 'On some Sea-water Level Marks on the Coast of Sweden.' 
 Quart. Geol. Journ. 1867, p. 187. 
 
CH. XXXL] RISE OF LAND IN SWEDEN. 139 
 
 an inner and an outer one ; the inner being the shore of the 
 mainland ; the outer one, a fringe of countless rocky islands 
 of all dimensions, called the skar (shair). Boats and small 
 vessels make their coasting voyages within this skar; for 
 here they may sail in smooth water, even when the sea 
 without is strongly agitated. But the navigation is very 
 intricate, and the pilot must possess a perfect acquaintance 
 with the breadth and depth of every narrow channel, and 
 the position of innumerable sunken rocks. If on such a 
 coast the land rises 1 or 2 feet in the course of half a 
 century, the minute topography of the skar is entirely altered. 
 To a stranger, indeed, who revisits it after an interval of 
 many years, its general aspect remains the same ; but the 
 inhabitant finds that he can no longer penetrate with his 
 boat through channels where he formerly passed, and he can 
 tell of countless other changes in the height and breadth of 
 isolated rocks, now exposed, but once only seen through the 
 clear water. 
 
 The rocks of gneiss, mica-schist, and quartz are usually 
 very hard on this coast, slow to decompose, and, when pro- 
 tected from the breakers, remaining for ages unaltered in 
 their form. Hence it is easy to mark the stages of their 
 progressive emergence by the aid of natural and artificial 
 marks imprinted on them. Besides the summits of fixed 
 rocks, there are numerous erratic blocks of vast size strewed 
 over the shoals and islands in the skar, which have been 
 probably drifted by ice in the manner before suggested.* All 
 these are observed to have increased in height and dimensions 
 within the last half-century. Some, which were formerly 
 known as dangerous sunken rocks, are now only hidden 
 when the water is highest. On their first appearance, they 
 usually present a smooth, bare, rounded protuberance, a few 
 feet or yards in diameter ; and a single sea-gull often appro- 
 priates to itself this resting-place, resorting there to devour 
 its prey. Similar points, in the meantime, have grown to 
 long reefs, and are constantly whitened by a multitude of 
 sea-fowl ; while others have been changed from a reef, 
 
 * See p. 182 and Chap. XVI. Vol. I. 
 
190 RISE OF LAND IN SWEDEN. [Cn. XXXI. 
 
 annually submerged, to a small islet, on which a few lichens, 
 a fir-seedling, and a few blades of grass, attest that the shoal 
 has at length been fairly changed into dry land. Thousands 
 of wooded islands around show the greater alterations which 
 time can work. In the course of centuries, also, the spaces 
 intervening between the existing islands may be laid dry, and 
 become grassy plains encircled by heights well clothed with 
 lofty firs. This last step of the process, by which long fiords 
 and narrow channels, once separating wooded islands, are 
 deserted by the sea, has been exemplified within the memory 
 of living witnesses on several parts of the coast. 
 
 It was admitted on all hands when I visited Sweden, in 
 1834, that the supposed change in the relative level of sea 
 and land was by no means going on at a uniform rate, or in 
 a uniform direction, at all points between the North Cape 
 and Scania, or the southermost part of Sweden, places 
 distant from each other more than 1,000 miles. The 
 rate of upheaval was said to be greatest at the North Cape, 
 but no accurate scientific proof of this fact has yet been 
 obtained. At Gefle, 90 miles north of Stockholm, the move- 
 ment may possibly, as before stated, amount to 2 or 3 feet in 
 a century, whereas at Stockholm it can hardly exceed 6 
 inches. 16 miles to the south-west of Stockholm, at 
 Sodertelje, the land seems to have been quite stationary 
 during the last century. Proceeding still farther south, the 
 upward movement seems to give place to one in an opposite 
 direction. In proof of this fact, Professor Nilsson has 
 remarked, in the first place, that there are no elevated beds 
 of recent marine shells in Scania like those farther to the 
 north. Secondly, Linnseus, with a view of ascertaining 
 whether the waters of the Baltic were retiring from the 
 Scanian shore, measured, in 1749, the distance between the 
 sea and a large stone near Trelleborg. This same stone 
 was, in 1836, a hundred feet nearer the water's edge than 
 in Linnseus's time, or 87 years before. Thirdly, there is 
 also a submerged peat moss, consisting of land and fresh- 
 water plants, beneath the sea at a point to which no peat 
 could have been drifted down by any river. Fourthly, and 
 what is still more conclusive, it is found that in seaport 
 
CH. XXXI.] KISE OF LAND IN SWEDEN. 191 
 
 towns, all along the coast of Scaiiia, there are streets below 
 the high-water level of the Baltic, and in some cases below 
 the level of the lowest tide. Thus, when the wind is high at 
 Malmo, the water overflows one of the present streets, and 
 some years ago some excavations showed an ancient street 
 in the same place 8 feet lower, and it was then seen that 
 there had been an artificial raising of the ground, doubtless 
 in consequence of that subsidence. There is also a street at 
 Trelleborg, and another at Skanor, a few inches below high- 
 water mark, and a street at Ystad is exactly on a level with 
 the sea, at which it could not have been originally built. 
 
 When we cross from the Gulf of Bothnia to the coast 
 north of Gothenburg, we find that the opinion still prevails 
 there, as it did in the days of Celsius, among the fishing and 
 seafaring inhabitants, that there is a slow sinking of the sea 
 going on; so that rocks, both on the shore of the main- 
 land and in the islands, are more and more exposed to view. 
 If this conclusion be confirmed by future observation, the 
 breadth of the tract from WNW. to ESE., which is rising, 
 must exceed 200 geographical miles, without including the 
 bed of the two seas adjacent to the coasts. 
 
 Hitherto we have confined our attention almost exclusively 
 to changes of level in historical times ; but we may next 
 enquire what geological proofs exist of the sojourn of the 
 sea on the land, at a very modern period, in those parts of 
 Sweden where there is ground for suspecting that a move- 
 ment of elevation is in progress. 
 
 In this case, the evidence is most satisfactory. Near 
 Uddevalla and the neighbouring coastland, we find upraised 
 deposits of shells belonging to species such as now live in 
 the ocean ; while on the opposite or eastern side of Sweden, 
 near Stockholm, Gefle, and other places bordering the 
 Bothnian Gulf, there are analogous beds containing shells of 
 species characteristic of the Baltic. 
 
 Yon Buch announced in 1807, that he had discovered in 
 Norway and at Uddevalla in Sweden, beds of shells of 
 existing species, at considerable heights above the sea. 
 Since that time, other naturalists have confirmed his ob- 
 servation; and, according to Torell, deposits occur at 
 
192 RISE OF LAND IN SWEDEN. [On. XXXI. 
 
 elevations of 600 and even 700 feet above the sea in some 
 parts of Norway. M. Alex. Brongniart, when he visited 
 Uddevalla, ascertained that one of the principal masses of 
 shells, that of Capellbacken, is raised more than 200 feet 
 above the sea, resting on rocks of gneiss, all the species being 
 identical with those now inhabiting the contiguous ocean. 
 The same naturalist also stated, that on examining with 'care 
 the surface of the gneiss, immediately above the ancient 
 shelly deposit, he found barnacles (balani) adhering to the 
 rocks, showing that the sea had remained there for a long 
 time. I was fortunate enough to be able to verify this 
 observation by finding in the summer of 1834, at Kured, 
 about 2 miles north of Uddevalla, and at the height of more 
 than 100 feet above the sea, a surface of gneiss newly laid 
 open by the partial removal of a mass of shells used largely 
 in the district for making lime and repairing the roads. So 
 firmly did these barnacles adhere to the gneiss, that I was 
 able to break off portions of the rock with the shells attached. 
 The face of the gneiss was also encrusted with bryozoa ; but 
 had these or the barnacles been exposed in the atmosphere 
 ever since the elevation of the rocks above the sea, they 
 would doubtless have decomposed and been obliterated. 
 
 The town of Uddevalla (see Map, p. 184) stands at the 
 head of a narrow creek overhung by steep and barren rocks 
 of gneiss, of which all the adjacent country is composed, 
 except in the low grounds and bottoms of valleys, where 
 strata of sand, clay, and marl frequently hide the funda- 
 mental rocks. To these newer and horizontal deposits, some- 
 times 40 feet thick, the fossil shells above mentioned belong, 
 and similar marine remains are found at about the same 
 height above the sea on the opposite island of Crust, as well 
 as in that of Tjorn, and at points near the coast still farther 
 south. 
 
 Mr. J. Gwyn Jeffreys visited Uddevalla in 1862, and collected 
 from the beds there 83 species of mollusca, characteristic of 
 the Glacial Period. He also obtained evidence that a littoral 
 and shallow-water deposit underlaid the shells proper to 
 deeper water ; a fact clearly implying a depression of the bed 
 of the sea previous to that upheaval which has since carried 
 
CH. XXXI.] EISE OF LAND IN SWEDEN. 193 
 
 up the land where the marine shells are found, to the height 
 of more than 200 feet.* As to the date of this last upheaval, 
 Mr. Torell has shown that it by no means reaches back to the 
 Glacial Period, to which the shells above ahaded to belong. 
 Those shells, so characteristic of a cold climate, are specifi- 
 cally identical with mollusca now living in the seas of Spitz- 
 bergen, 10 degrees of latitude north of Uddevalla. But in 
 some recent deposits near Uddevalla, Mr. Torell detected, 
 at the height of 200 feet above the sea, the remains of 
 marine testacea, agreeing with species now proper to the 
 fauna of the adjacent and more temperate sea.f It appears, 
 therefore, that the series of movements in the district under 
 consideration consisted, first, of a depression converting the 
 shallow water into deep sea at a time when the cold was very 
 severe, and then of an elevation of more than 200 feefc when 
 the waters of the sea had acquired their present milder 
 temperature. 
 
 To return now to the coast of the Baltic. I observed 
 near the shores of the Gulf of Bothnia, at Sodertelje, 16 
 miles SW. of Stockholm, strata of sand, clay, and marl, 
 more than 100 feet high, and containing shells of species now 
 inhabiting the gulf. These consist partly of marine and 
 partly of freshwater species ; but they are few in number, 
 the brackishness of the water appearing to be very unfavour- 
 able to the development of testacea. The most abundant 
 species are the common cockle and the common mussel and 
 periwinkle of our shores (Cardium edule, Hytilus edulis, and 
 Littorina littorea), together with a small tellina (T. Baltica, 
 L.; T. solidula, Pult.), and a few minute univalves allied to 
 Paludina ulva. These live in the same water as a Lymneus, 
 a Neritina (N . fluviatilis) , and some other freshwater shells. 
 
 But the marine mollusks of the Baltic above mentioned, 
 although very numerous in individuals, are dwarfish in size, 
 scarcely ever attaining a third of the average dimensions 
 which they acquire in the salter waters of the ocean. By 
 this character alone a geologist would generally be able to 
 
 * Gwyn Jeffrey's Keport to Brit. to Molluscous Fauna of Spitzbergen. 
 Assoc. 1863, p. 73. 1859. 
 
 f Torell, Beitrage, &c. Contributions 
 
 VOL. II. O 
 
194 RISE OF LAND IN SWEDEN. [Cn XXXI. 
 
 recognise at once an assemblage of Baltic fossils as distin- 
 guished from those derived from a deposit in the ocean. The 
 absence also of oysters, barnacles, whelks, scallops, limpets 
 (ostreaybalanuSybuccinumypectenypatella^y&ud many other forms 
 abounding alike in the sea near Uddevalla, and in the fos- 
 siliferous deposits of modern date on that coast, supplies an 
 additional negative character of the greatest value, distin- 
 guishing assemblages of Baltic from those of oceanic shells. 
 Now the strata containing Baltic shells are found in many 
 localities near Stockholm, Upsala, and Gene, and will pro- 
 bably be discovered everywhere around the borders of the 
 Bothnian Gulf; for I have seen similar remains brought 
 from Finland, in marl resembling that found near Stockholm. 
 The utmost distance to which these deposits had been traced 
 inland in 1835 was on the southern shores of Lake Maeler, 
 at a place 70 miles from the sea, but they have since been 
 traced by Erdmann to Linde, at the head of a lake of* that 
 name, to a distance of 130 miles west of Stockholm, and to a 
 height of about 230 feet above the sea. Hence it appears, from 
 the distinct assemblage of fossil shells found on the eastern 
 and western coasts of Sweden, that the Baltic has been for a 
 long period separated as now from the ocean, although the 
 intervening tract of land was once much narrower, even 
 after both seas had become inhabited by all the existing 
 species of testacea. 
 
 Whether any of the land in Norway is now rising, must 
 be determined by future investigations. Marine fossil shells, 
 of recent species, have been collected from inland places 
 near Drontheiru ; but Mr. Everest, in his c Travels through 
 Norway,' informs us that the small island of Munkholm, 
 which is an insulated rock in the harbour of Drontheim, 
 affords conclusive evidence of the land having in that region 
 remained stationary for the last 8 centuries. The area of 
 this isle does not exceed that of a small village ; and by an 
 official survey, its highest point has been determined to be 
 23 feet above the mean high-water mark, that is, the mean 
 between neap and spring tides. Now, a monastery was 
 founded there by Canute the Great, A.D. 1028, and 33 years 
 before that time it was in use as a common place of execution. 
 
CH. XXXI.] RISE OF LAND IN NORWAY. 195 
 
 According to the assumed average rate of rise in Sweden 
 (about 40 inches in a century), we should be obliged to 
 suppose that this island had been 3 feet 8 inches below high- 
 water mark when it was originally chosen as the site of the 
 monastery. 
 
 Professor Keilhau of Christiania, after collecting the ob- 
 servations of his predecessors respecting former changes of 
 level in Norway, and combining them with his own, has 
 made the fact of a general change of level at some unknown 
 but, geologically speaking, modern period (that is to say, 
 within the period of the actual testaceous fauna), very 
 evident. He infers that the whole country from Cape Lin- 
 desnses to Cape North, and beyond that as far as the fortress 
 of Yardhuus, has been gradually upraised, and on the south- 
 east coast the elevation has amounted to more than 600 feet. 
 The marks which denote the ancient coast-lines are so 
 nearly horizontal, that the deviation from horizontality, 
 although the measurements have been made at a great 
 number of points, is too small to be appreciated. 
 
 More recently (1844), however, it appears from the researches 
 of M. Bravais, member of the French scientific commission 
 of the North, that in the Gulf of Alten in Finmark, the 
 most northerly part of Norway, there are two distinct lines 
 of upraised ancient sea-coast, one above the other, which are 
 not parallel, and both of them imply that within a distance 
 of 50 miles a considerable slope can be detected in such a 
 direction as to show that the ancient shores have undergone 
 a greater amount of upheaval in proportion as we advance 
 inland.* 
 
 The different heights at which horizontal raised beaches 
 containing recent shells have been observed along the western 
 and northern coasts of Norway, have been supposed to prove 
 the suddenness of the upheaval of the land at successive 
 periods ; but when truly interpreted, these appearances prove 
 rather that the elevatory force has been intermittent in its 
 action, and that there have been long pauses in the process 
 
 * Quarterly Journ. of Geol. Soc. No. 4, verified in 1849 by Mr. R. Chambers in 
 p. 534. M. Bravais' observations were his ' Tracings of N. of Europe.' p. 208. 
 
 o 2 
 
196 SUBSIDENCE IN PART OF GREENLAND. [Cn. XXXI. 
 
 of upheaval. They mark eras at which the level of the sea 
 has remained stationary for ages, and during which new 
 strata were deposited near or on the shore in some places, 
 while in others the waves and currents had time to hollow 
 out rocks, undermine cliffs, and throw up long ranges oi 
 shingle. They undoubtedly show that the movement has 
 not been always uniform or continuous, but they do not 
 establish the fact of any sudden alterations of level. 
 
 Subsidence in part of Greenland. The rise of Scandinavia 
 has naturally been regarded as a very singular and scarcely 
 credible phenomenon, because no region on the globe has 
 been more free within the times of authentic history from 
 violent earthquakes. In common, indeed, with our own 
 island and with almost every spot on the globe, some move- 
 ments have been, at different periods, experienced, both in 
 Norway and Sweden. But some of these, as for example 
 during the Lisbon earthquake in 1755, may have been mere 
 vibrations or undulatory movements of the earth's crust 
 prolonged from a great distance. Others, however, have 
 been sufficiently local to indicate a source of disturbance 
 immediately under the country itself. Notwithstanding 
 these shocks, Scandinavia has, upon the whole, been as 
 tranquil in modern times, and as free from subterranean 
 convulsions, as any region of equal extent on the globe. 
 The same may be said of another large area in Greenland, 
 which in modern times has been undergoing a slow and 
 insensible movement, but in an opposite direction. Two 
 Danish investigators, Dr. Pingel and Captain Graah, have 
 brought to light abundant evidence of the sinking down oi 
 part of the west coast of Greenland, for a space of more than 
 600 miles from north to south. The observations of Captain 
 Graah were made during a survey of Greenland in 1823-24 ; 
 and afterwards in 1828-29 ; those by Dr. Pingel were made 
 in 1830-32. It appears from various signs and traditions, 
 that the coast has been subsiding for the last 4 centuries 
 from the firth called Igaliko, in lat. 60 43' N., to Disco 
 Bay, extending to nearly the 69th degree of north latitude. 
 Ancient buildings on low rocky islands and on the shore of 
 the mainland have been gradually submerged, and experience 
 
DH. XXXI.] CHANGES OF LEVEL, HOW CAUSED. 197 
 
 h.as taught the aboriginal Greenlander never to build his hut 
 near the water's edge. In one case the Moravian settlers 
 have been obliged more than once to move inland the poles 
 upon which their large boats were set, and the old poles 
 still remain beneath the water as silent witnesses of the 
 change.* 
 
 The fact of the gradual elevation and depression of land 
 throughout vast areas of Europe and Arctic America, which 
 we have considered in this chapter, partly in the historical 
 period and partly in geological times immediately antecedent, 
 lead us naturally to speculate on the wonderful changes 
 which must be continually in progress in the subterranean 
 foundations of these same countries. Whether we ascribe 
 these changes to the expansion of solid matter exposed to 
 hydrothermal action, or to the melting of rock, or the solidi- 
 fication of mineral masses, in whatever conjectures we indulge, 
 we cannot doubt that at some unknown depths the structure 
 of the crust of our globe is gradually undergoing very im- 
 portant modifications. 
 
 * See Proceedings of Geol. Soc. No. Pingel on the subject at Copenhagen in 
 42, p. 208. I also conversed with Dr. 1834. 
 
198 
 
 CHAPTER XXXII. 
 
 CAUSES OF EARTHQUAKES AND VOLCANO?. 
 
 INTIMATE CONNECTION BETWEEN THE CAUSES OF VOLCANOS AND EARTH- 
 QUAKESSUPPOSED ORIGINAL STATE OF FUSION OF THE PLANET ITS SIMUL- 
 TANEOUS AND UNIVERSAL FLUIDITY NOT PROVED BY ITS SPHEROIDAL FIGURE 
 
 ATTEMPT TO CALCULATE THE THICKNESS OF THE SOLID CRUST OF THE EARTH 
 
 BY PRECESSIONAL MOTION HEAT OF EARTH'S CRUST INCREASING WITH THK 
 
 DEPTH, BUT NOT EQUALLY NO INTERNAL TIDES OF SUPPOSED CENTRAL 
 
 FLUID PERCEPTIBLE SUPPOSED CHANGE OF AXIS OF EARTH' S CRUST PARTIAL 
 
 FLUIDITY OF THE EARTH*S CRUST MOST CONSISTENT WITH VOLCANIC PHE- 
 NOMENA OF THE PAST AND PRESENT ABANDONMENT OF THE DATA BY WHICH 
 
 THE EARLIER GEOLOGISTS SUPPORTED THKIR THEORY OF THE PRISTINE 
 FLUIDITY OF THE EARTH'S CRUST DOCTRINE OF A CONTINUAL DIMINUTION 
 OF TERRESTRIAL AND SOLAR HEAT CONSIDERED. 
 
 IT will hardly be questioned, after the description before 
 given of the phenomena of earthquakes and volcanos, that 
 both of these agents have, to a certain extent, a common 
 origin ; and I may now, therefore, proceed to enquire into 
 their probable causes. But, first, it may be well to re- 
 capitulate some of those points of relation and analogy which 
 lead naturally to the conclusion that they spring from a 
 common source. 
 
 The regions convulsed by violent earthquakes include 
 within them the site of all the active volcanos. Earth- 
 quakes, sometimes local, sometimes extending over vast 
 areas, often precede volcanic eruptions. The subterranean 
 movement and the eruption return again and again, at ir- 
 regular intervals of time, and with unequal degrees of force, 
 to the same spots. The action of either may continue for a 
 few hours, or for several consecutive years. Paroxysmal 
 convulsions are usually followed, in both cases, by long 
 periods of tranquillity.- Thermal and mineral springs are 
 abundant in countries of earthquakes and active volcanos. 
 Lastly, springs situated in districts considerably distant 
 
CH. XXXIL] SUPPOSED CENTRAL FLUIDITY OF THE EARTH. 199 
 
 from volcanic vents have been observed to have their tem- 
 perature suddenly raised or lowered, and the volume of their 
 water increased or lessened, by subterranean movements. 
 
 All these appearances are evidently more or less connected 
 with the passage of heat from the interior of the earth to 
 the surface ; and where there are active volcanos, there 
 must exist, at some unknown depth below, enormous masses 
 of matter intensely heated, and, in many instances, in a 
 constant state of fusion. We have first, then, to enquire, 
 whence is this heat derived ? 
 
 Supposed central fluidity of the earth. It has long been 
 a favourite conjecture, that the whole of our planet was 
 originally in a state of igneous fusion, and that the central 
 parts still retain a great portion of their primitive heat. 
 Some have imagined, with the late Sir W. Herschel, that the 
 elementary matter of the earth may have been first in a 
 gaseous btate, resembling those iiebulse which we behold in 
 the heavens, and which are of dimensions so vast, that some 
 of them would fill the orbits of the remotest planets of our 
 system. The increased power of the telescope has of late 
 years resolved the greater number of these nebulous ap- 
 pearances into clusters of stars ; but so long as they were 
 confidently supposed to consist of aeriform matter, it was a 
 favourite conjecture that they might, if concentrated, form 
 solid spheres ; and it was also imagined that the evolution 
 of heat, attendant on condensation, might retain the ma- 
 terials of the new globes in a state of igneous fusion. 
 
 Without dwelling on such speculations, which can only 
 have a distant bearing on geology, we may consider how far 
 the spheroidal form of the earth affords sufficient ground 
 for presuming that its primitive condition was one of universal 
 fluidity. The discussion of this question would be superfluous, 
 were the doctrine of original fluidity less popular; for it 
 may well be asked, why the globe should be supposed to 
 have had a pristine shape different from the present one ? 
 why the terrestrial materials, when first called into existence, 
 or assembled together in one place, should not have been 
 subject to rotation, so as to assume at once that form 
 
200 SPHEROIDAL FORM OF THE EARTH. [Cn. XXXIT. 
 
 which alone could retain their several parts in a state of 
 equilibrium ? 
 
 Let us, however, concede that the statical figure may be 
 a modification of some other pre-existing form, and suppose 
 the globe to have been at first a perfect and quiescent 
 sphere, covered with a uniform ocean what would happen 
 when it was made to turn round on its axis with its present 
 velocity ? This problem has been considered by Playfair 
 in his Illustrations ; and he has decided, that if the surface 
 of the earth, as laid down in Button's theory, has been 
 repeatedly changed by the transportation of the detritus of 
 the land to the bottom of the sea, the figure of the planet 
 must in that case, whatever it may have been originally, 
 be brought at length to coincide with the spheroid of equi- 
 librium.* Sir John Herschel also, in reference to the same 
 hypothesis, observes, ' A centrifugal force would in that case 
 be generated, whose general tendency would be to urge the 
 water at every point of the surface to recede from the axis. 
 A rotation might indeed be conceived so swift as to flirt the 
 whole ocean from the surface, like water from a mop. But 
 this would require a far greater velocity than what we now 
 speak of. In the case supposed, the weight of the water 
 would still keep it on the earth ; and the tendency to recede 
 from the axis could only be satisfied therefore by the water 
 leaving the poles, and flowing towards the equator ; there 
 heaping itself up in a ridge, and being retained in opposition 
 to its weight or natural tendency towards the centre by the 
 pressure thus caused. This, however, could not take place 
 without laying dry the polar regions, so that protuberant 
 land would appear at the poles, and a zone of ocean be 
 disposed around the equator. This would be the first or 
 immediate effect. Let us now see what would afterwards 
 happen if things were allowed to take their natural course. 
 
 ' The sea is constantly beating on the land, grinding it 
 down, and scattering its worn-off particles and fragments, 
 in the state of sand and pebbles, over its bed. Geological 
 facts afford abundant proof that the existing continents have 
 
 * Illust, of Hutt. Theory, 435443. 
 
CH. XXXII.] SPHEROIDAL FORM OF THE EARTH. 201 
 
 all of them undergone this process even more than once, 
 and been entirely torn in fragments, or reduced to powder, 
 and submerged and reconstructed. Land, in this view of 
 the subject, loses its attribute of fixity. As a mass, it might 
 hold together in opposition to forces which the water freely 
 obeys j but in its state of successive or simultaneous degra- 
 dation, when disseminated through the water, in the state 
 of sand or mud, it is subject to all the impulses of that fluid. 
 In the lapse of time, then, the protuberant land would be 
 destroyed, and spread over the bottom of the ocean, filling 
 up the lower parts, and tending continually to remodel the 
 surface of the solid nucleus, in correspondence with the 
 form of equilibrium. Thus, after a sufficient lapse of time, in 
 the case of an earth in rotation, the polar protuberances 
 would gradually be cut down and disappear, being trans- 
 ferred to the equator (as being then the deepest sea], till the 
 earth would assume by degrees the form we observe it to 
 have that of a flattened or oblate ellipsoid. 
 
 ' We are far from meaning here to trace the process by 
 which the earth really assumed its actual form ; all we intend 
 is to show that this is the form to which, under a condition 
 of a rotation on its axis, it must tend, and which it would 
 attain even if originally and (so to speak) perversely consti- 
 tuted otherwise.' * . 
 
 Although in the above passage no mention is made of 
 rivers, yet it must be understood that they would play a 
 leading part in the degradation of the polar land under the 
 condition above assumed. Sir J. Herschel has also confined 
 his observations to the effects of aqueous causes only ; neither 
 he nor Playfair seem to have followed out the same enquiry 
 with reference to another part of Hutton's system ; namely, 
 that which assumes the successive fusion by heat of different 
 parts of the solid earth. Yet the progress of geology has 
 continually strengthened the evidence in favour of the doctrine 
 that local variations of temperature have melted one part after 
 another of the earth's crust, and this influence has perhaps 
 extended downwards to the very centre. If, therefore, before 
 
 * Herschel's Astronomy, chap. iii. 
 
202 DENSITY OF THE EARTH. [Cn. XXXII. 
 
 the globe had assumed its present form, it was made to revolve 
 on its axis, all matter to which freedom of motion was given 
 by fusion, must before consolidating have been impelled 
 towards the equatorial regions in obedience to the centrifugal 
 force. Thus, lava flowing out in superficial streams would 
 have its motion retarded when its direction was towards the 
 pole, accelerated when towards the equator, or if lakes and 
 seas of lava existed beneath the earth's crust in equatorial 
 regions, as probably now beneath the Peruvian Andes, the 
 imprisoned fluid would force outwards and permanently 
 upheave the overlying rocks. The statical figure, therefore, 
 of the terrestrial spheroid (of which the longest diameter 
 exceeds the shortest by about twenty-five miles), may have 
 been the result of gradual and even of existing causes, and 
 not of a primitive, universal, and simultaneous fluidity.* 
 
 Experiments made with the pendulum, and observations 
 on the manner in which the earth attracts the moon, have 
 shown that our planet is riot an empty sphere, but, on the 
 contrary, that its interior, whether solid or fluid, has a higher 
 specific gravity than the exterior. It has also been inferred 
 from certain inequalities in the moon's motion, that there is 
 a regular increase in density from the surface towards the 
 centre, and that the equatorial protuberance is continued 
 inwards ; that is to say, that layers of equal density are 
 arranged elliptically, and symmetrically, from the exterior to 
 the centre. 
 
 The mean density of the earth has been computed by 
 Laplace to be about 5J, or more than 5 times that of water. 
 Now the specific gravity of many of our rocks is from 2 J to 
 3, and the greater part of the metals range between that 
 density and 21. Hence some have imagined that the terres- 
 trial nucleus may be metallic that it may correspond, for 
 example, with the specific gravity of iron, which is about 7. 
 But here a curious question arises in regard to the form 
 which materials, whether fluid or solid, might assume, if 
 subjected to the enormous pressure which must obtain at the 
 earth's centre. Water, if it continued to decrease in volume 
 
 * See Hennessy, On Changes in Dublin, 1849 ; and Proc. Roy. Irish 
 Earth's Figure, &c. Journ. Geol. Soc. Acad. vol. iv. p. 337. 
 
CH. XXXII.] THICKNESS OF EARTH'S CRUST. 203 
 
 according to the rate of compressibility deduced from experi- 
 ment, would have its density doubled at the depth of 93 miles, 
 and be as heavy as mercury at the depth of 362 miles. Dr. 
 Young computed that, at the earth's centre, steel would be 
 compressed into one-fourth, and stone into one-eighth of its 
 bulk.* It is more than probable, however, that after a 
 certain degree of condensation, the compressibility of bodies 
 may be governed by laws altogether different from those 
 which we can put to the test of experiment ; but the limit is 
 still undetermined, and the subject is involved in such ob- 
 scurity, that we cannot wonder at the variety of notions 
 which have been entertained respecting the nature and con- 
 ditions of the central nucleus. Some have conceived it to be 
 fluid, others solid ; some have imagined it to have a cavernous 
 structure, and have even endeavoured to confirm this opinion 
 by appealing to observed irregularities in the vibrations of 
 the pendulum in certain countries. 
 
 An attempt has been made by Mr. Hopkins to determine 
 the least thickness which can be assigned to the solid crust 
 of the globe, if we assume the whole to have been once 
 perfectly fluid, and a certain portion of the exterior to have 
 acquired solidity by gradual refrigeration. This result he 
 has endeavoured to obtain by a new solution of the delicate 
 problem of the precessional motion of the pole of the earth, 
 caused, as before mentioned, p. 274, Yol. I., by the attraction 
 of the sun and moon, and principally the moon, on the 
 protuberant parts at the earth's equator ; for if these parts 
 were solid to a great depth, the motion thus produced would 
 differ considerably from that which would exist if they were 
 perfectly fluid, and incrusted over with a thin shell only a 
 few miles thick. In other words, the disturbing action of 
 the moon will not be the same upon a globe all solid and 
 upon one nearly all fluid, or it will not be the same upon a 
 globe in which the solid shell forms one-half of the mass, 
 and another in which it forms only one-tenth. 
 
 Mr. Hopkins has, therefore, calculated the amount of 
 precessional motion which would result if we assume the 
 
 * Young's Lectures, and Mrs. Somerville's Connection of the Physical Sciences, 
 p. 90. 
 
204 RATE OF HEAT INCREASING WITH DEPTH. [Cn. XXXII. 
 
 earth, to be constituted as above stated ; i. e. fluid internally, 
 and enveloped by a solid shell ; and he finds that the amount 
 will not agree with the observed motion, unless the crust of 
 the earth be of a certain thickness. In calculating the exact 
 amount, some ambiguity arises in consequence of our ignorance 
 of the effect of pressure in promoting the solidification of 
 matter at high temperatures. The hypothesis least favourable 
 for a great thickness is found to be that which assumes the 
 pressure to produce no effect on the process of solidification. 
 Even on this extreme assumption, the thickness of the solid 
 crust must be nearly four hundred miles, and this would lead 
 to the remarkable result that the proportion of the solid to 
 the fluid part would be as 49 to 51, or, to speak in round 
 numbers, there would be nearly as much solid as fluid matter 
 in the globe. The conclusion, however, which Mr. Hopkins 
 announces as that to which his researches have finally con- 
 ducted him, is thus expressed : * Upon the whole, then, we 
 may venture to assert that the minimum thickness of the 
 crust of the globe, which can be deemed consistent with the 
 observed amount of precession, cannot be less than one fourth 
 or one-fifth of the earth's radius ; ' that is, from 800 to 1,000 
 miles.* 
 
 It will be remarked, that this is a minimum, and any still 
 greater amount would be quite consistent with the actual 
 phenomena ; the calculations not being opposed to the sup- 
 position of the general solidity of the entire globe. Nor do 
 they preclude us from imagining that great lakes and seas of 
 melted matter may be distributed through a shell 400 or 800 
 miles thick, provided they be so inclosed as to move with it, 
 whatever motion of rotation may be communicated by the 
 disturbing forces of the sun and moon. 
 
 Rate of heat increasing with depth. The hypothesis of 
 internal fluidity calls for the more attentive consideration, 
 as it has been found that the heat in mines augments in pro- 
 portion as we descend. Observations have been made, not 
 only on the temperature of the air in mines, but on that of 
 
 * Phil. Trans. 1839, and Researches Phenomena and Theory of Volcanos, 
 in Physical Geology, 1st, 2nd, and 3rd Report Brit. Assoc. 1847. 
 series, London, 18391842 ; also on 
 
CH. XXXIL] THEOEY OF CENTRAL HEAT. 205 
 
 the rocks, and on the water issuing from them. The mean 
 rate of increase, calculated from the most careful experiments 
 yet made in 2 shafts, one near Durham, and another near 
 Manchester, each of them 2,000 feet deep, is 1 Fahrenheit 
 for every increase of depth of from 65 to 70 feet, a rate of 
 increase considerably less than that previously deduced from 
 coal-mines in the same districts.* This rate, however, agrees 
 very nearly with previous observations made in several of 
 the principal lead and silver mines in Saxony, which gave 
 1 Fahr. for every 65 feet. In this case, the bulb of the 
 thermometer was introduced into cavities purposely cut in 
 the solid rock at depths varying from 200 to about 900 
 feet. But in other mines of the same country, it was 
 necessary to descend thrice as far for each degree of tem- 
 perature, f 
 
 A thermometer was fixed in the rock of the Dolcoath 
 mine, in Cornwall, by Mr. Fox, at the great depth of 1,380 
 feet, and frequently observed during 18 months ; the mean 
 temperature was 68 Fahr., that of the surface being 50, 
 which gives 1 for every 75 feet. 
 
 Kupffer, after an extensive comparison of the results in 
 different countries, makes the increase 1 Fahr. for about 
 every 37 English feet.J M. Cordier announces, as the result 
 of his experiments and observations on the temperature of 
 the interior of the earth, that the heat increases rapidly with 
 the depth ; but the increase does not follow the same law 
 over the whole earth, being twice or three times as much in 
 one country as in another, and these differences are not in 
 constant relation either with the latitudes or longitudes of 
 places. He is of opinion, however, that the increase would 
 not be overstated at 1 Cent, for every 25 metres, or about 
 1 Fahr. for every 45 feet. The experimental well bored at 
 Grenelle, near Paris, gave, as before stated (Yol. I. p. 390), an 
 increase of about 1 Fahr. for every 60 English feet to the 
 depth of 1,800 feet. 
 
 * These observations were made by Temperature of the Interior of the 
 
 Professor Philips. Earth, June, 1827. Mem. de 1'Instit. 
 
 t Cordier, Mem. de 1'Instit. torn. vii. torn, vii., and Edin. New Phil. Journal, 
 
 | Pog. Ann. torn. xv. p. 159. No. viii. p. 273. 
 See M. Cordier's Memoir on the 
 
206 THEORY OF CENTRAL HEAT. [On. XXXII. 
 
 At Naples, according to Mr. Mallet, the water in the Artesian 
 well at the .Royal Palace, at the depth of 1,460 feet, has a 
 temperature of only 68 Fahr., which, deducting for the 
 mean temperature of the surface soil, 61 Fahr., gives an 
 increment of only 1 Fahr. for every 208 feet in depth. 
 Another well in the same city, only a mile distant from the 
 former and 909 feet deep, gives 1 Fahr. for 83 feet in depth. 
 It is conjectured that the low temperature of the well first 
 mentioned may be due to the cooling influence both of fresh 
 and sea water which may be filtered through porous beds of 
 tufa. 
 
 Some writers have endeavoured to refer these phenomena 
 (which, however discordant as to the ratio of increasing heat, 
 appear all to point one way) to the condensation of air con- 
 stantly descending from the surface into the mines. For the 
 air under pressure would give out latent heat, on the same 
 principle as it becomes colder when rarefied in the higher 
 regions of the atmosphere. But, besides that the quantity 
 of heat is greater than could be supposed to flow from this 
 source, the argument has been answered in a satisfactory 
 manner by Mr. Fox, who has shown, that in the mines of 
 Cornwall the ascending have generally a higher temperature 
 than the descending aerial currents. The difference between 
 them was found to vary from 9 to 17 Fahr. : a proof that, 
 instead of imparting heat, these currents actually carry off a 
 large quantity from the mines. * 
 
 If we adopt the mean increase of 1 Fahr. for every 65 feet 
 of depth, and assume, with the advocates of central fluidity, 
 that the increasing temperature is, continued downwards for 
 an indefinite distance, we should reach the ordinary boiling 
 point of water at rather more than 2 miles below the surface, 
 and at the depth of about 34 miles should arrive at the 
 melting point of iron, or 2,786 Fahr. according to DanielPs 
 pyrometer, a heat sufficient to fuse almost every known sub- 
 stance. In the diagram, fig. 128, p. 212, the outer circular 
 line represents a thickness of 25 miles, and the space between 
 the 2 circles, together with the lines themselves, represents a 
 crust of 200 miles in depth. If, therefore, the heat went on 
 
 * Phil. Mag. and Ann. Feb. 1830. 
 
CH. XXX1L] THEORY OF CENTRAL HEAT. 207 
 
 increasing at the rate above alluded to, we should encounter 
 not far below the outer line a temperature many times 
 greater than that sufficient to melt the most refractory sub- 
 stances known to us. At much greater depths, and long 
 before approaching the central nucleus, the heat would be so 
 intense (160 times that of melted iron), that we cannot con- 
 ceive the external crust to resist fusion.* 
 
 It may be said that we may stand upon the hardened sur- 
 face of a lava current while it is still in motion nay, may 
 descend into the crater of Vesuvius after an eruption, and 
 stand on the scoriae while every crevice shows that the rock 
 is red-hot 2 or 3 feet below us ; and at a somewhat greater 
 depth, all is, perhaps, in a state of fusion. May not, then, 
 a much more intense heat be expected at the depth of several 
 hundred yards or miles? The answer is, that, until a 
 great quantity of heat has been given off, either by the 
 emission of lava, or in a latent form by the evolution of 
 steam and gas, the melted matter continues to boil in the 
 crater of a volcano. But ebullition ceases when there is no 
 longer a sufficient supply of heat from below, and then a 
 crust of lava may form on the top, and showers of scoriae 
 may then descend upon the surface, and remain unmelted. 
 If the internal heat be raised again, ebullition will recom- 
 mence, and soon fuse the superficial crust. So in the case 
 of the moving current, we may safely assume that no part of 
 the liquid beneath the hardened surface is much above the 
 temperature sufficient to retain it in a state of fluidity. 
 
 M. Poisson, in his Mathematical Theory of Heat, published 
 in 1835, controverted the doctrine of the high temperature of 
 a central nucleus, and declared his opinion that if the globe 
 had ever passed from a liquid to a solid state in consequence 
 of the loss of heat by radiation, the cooling and consolidation 
 of the nucleus would have begun at the earth's centre. 
 
 * The expansion of platinum was the other test yet invented for measuring 
 
 test employed by Mr. Daniell, in his intense heat, can be fully depended upon, 
 
 pyrometer, which was found to yield Malleable iron, he remarks, requires 
 
 uniform and constant results, in har- more heat for its fusion than wrought 
 
 mony with those derived from other iron, in which the metal is mixed with a 
 
 independent sources. But Dr. Percy small percentage of carbon, 
 informs me that neither this nor any 
 
208 SUPPOSED CHANGE OF AXIS OF EARTH'S CRUST. [Cn. XXXII. 
 
 No internal tides. Many of the advocates of central fluidity 
 have admitted that there must be tides in the internal ocean; 
 but their effect, says Cordier, has become feeble, although 
 originally, when the fluidity of the globe was perfect, ' the 
 rise and fall of these ancient land tides could not have been 
 less than from 13 to 16 feet.' Now, granting for a moment 
 that these tides have become so feeble as to be incapable of 
 causing .the fissured shell of the earth to be first uplifted and 
 then depressed every 6 hours, still may we not ask whether, 
 in every volcano during an eruption, the lava, which is sup- 
 posed to communicate with a great central ocean, would not 
 rise and fall sensibly, or whether, in a crater like Stroinboli, 
 where there is always melted matter in a state of ebullition, 
 the ebbing and flowing of the liquid would not be constant ? 
 
 Supposed change of axis of earth's crust. I alluded in 
 Chapter XIII. to an ingenious paper,* replete with specula- 
 tions of no ordinary interest, by Mr. Evans, in which he 
 suggested that former changes of climate on the surface 
 might be connected with the sliding of a solid shell over an 
 internal fluid nucleus. Granting for the moment the fluidity, 
 the equilibrium of the external shell might, no doubt, be 
 disturbed by the transfer of the sediment from one part of 
 the surface to another, or by the upheaval of new continents 
 and islands ; and Mr. Evans shows that, whenever matter is 
 abstracted from one part and added to another, the centri- 
 fugal force of the augmented extraneous matter would tend 
 to draw over the shell towards the equator, or an opposite 
 effect would be produced if the surface was relieved of part 
 of its weight, in which case the lighter part would move 
 towards the pole. 
 
 Newton, and afterwards Laplace, had argued against the 
 probability of a shifting of the earth's axis of rotation, and 
 more recently Mr. Airy had among other arguments pointed 
 out that the elevation of mountain chains at certain geolo- 
 gical periods, which had been proposed as causing an altera- 
 tion in the earth's centre of gravity, was an insignificant 
 cause, since the size of such mountain masses was very 
 minute when compared to the equatorial protuberance, 
 
 * T. Evans, Royal Society Proceedings, 1866. 
 
CH. XXXII.] PARTIAL FLUIDITY OF EARTH'S CRUST. 209 
 
 which he says is a mass of matter 25,000 miles long, 
 6,000 miles broad, and 13 miles deep. But Mr, Evans 
 suggests that the axis of rotation of the nucleus might 
 remain unchanged, while a solid shell not more, perhaps, 
 than 25 miles in thickness might have its axis of rotation 
 altered. To this hypothesis there are several objections : 
 
 First, in all geological times, the transfer of sediment has 
 been taking place not only from higher to lower latitudes, 
 but also from lower to higher. There is the like tendency in 
 the various elevations and depressions of land simultane- 
 ously in progress to balance each other. It is only the 
 excess of alteration in one direction that can be available as 
 a disturbing cause, and we can hardly imagine this excess 
 to be important enough to cause a sensible change in the 
 axis of rotation even of the external shell, such as might 
 explain the altered climate of the same country in successive 
 geological periods. 
 
 Secondly, a greater difficulty arises out of the fact that 
 the earth is a spheroid and not a perfect sphere, since it 
 becomes necessary to imagine the fluidity of the nucleus to 
 be so perfect as to allow the shell to slide freely over it. If 
 the lower or inner surface of the envelope be irregular in 
 shape, or if it be even viscous in part, great resistance 
 would be offered to any change in its position. Its freedom 
 of motion would be checked by its not fitting the nucleus, 
 let its change of position be ever so slight, and this change 
 could only be effected by the most violent friction, attended 
 by the bending and rending of the incumbent mass. 
 
 Partial fluidity of the earth's crust most consistent with 
 volcanic phenomena. It must not be forgotten that the 
 geological speculations still in vogue respecting the original 
 fluidity of the planet, and the gradual consolidation of 
 its external shell, belong to a period when theoretical ideas 
 were entertained as to the relative age of the crystalline 
 foundations of that shell wholly at variance with the present 
 state of om* knowledge. It was formerly imagined that all 
 granite was of very high antiquity, and that rocks such as 
 gneiss, mica-schist, and clay slate, were also anterior in date 
 to the existence of organic beings on a habitable surface. It 
 
 VOL. II. P 
 
210 THE EARTH'S CENTRAL FLUIDITY QUESTIONED. [Cn. XXXII- 
 
 was, moreover, supposed that these primitive formations, as 
 they were called, implied a continual thickening of the crust 
 at the expense of the original fluid nucleus. These notions 
 have been universally abandoned. It is now ascertained 
 that the granites of different regions are by no means all of 
 the same antiquity, and that it is hardly possible to prove any 
 one of them to be as old as the oldest known fossil organic 
 remains. It is likewise now admitted, that gneiss and other 
 stratified crystalline strata are sedimentary deposits which 
 have undergone metamorphic action, and they can almost 
 all be demonstrated to be newer than the lately discovered 
 fossil called Eozoon Canadense. It follows from such views, 
 which are of comparatively modern date, that instead of 
 these crystalline rocks, which are often of enormous volume, 
 implying a constant thickening of the earth's crust from 
 the remotest periods, they most of them bear testimony to 
 aqueous denudation on a vast scale, or, in other words, they 
 bespeak the removal of just as much solid matter from one part 
 of the earth's circumference as has been contemporaneously 
 accumulated in the shape of new strata in some other part. 
 It was, moreover, taken for granted by the earlier theorists, 
 without any sufficient geological proof, that the energy of 
 the volcanic force was far more intense in the remoter 
 periods of the earth's history than in the later. No adequate 
 conception had been formed of the great lapse of time occu- 
 pied in the elaboration of each of the principal groups of 
 the primary, secondary, and tertiary fossiliferous rocks, and 
 of the gradual manner in which contemporaneous volcanic 
 products were locally developed during each of those periods. 
 The limited areas to which the volcanic outbursts were 
 confined at any one epoch, the Cretaceous for example, is 
 proved by the general absence in strata of the same age of 
 associated igneous formations. It can be demonstrated that 
 the volcanic power was by no means dormant, but it was 
 locally developed. There are wide tracts in North America 
 and Eussia where very ancient strata, such as the Silurian and 
 Carboniferous, are horizontal and undisturbed, and wholly de- 
 void of contemporaneous igneous products, showing that such 
 areas were not only free from volcanic action in palaeozoic 
 
CH. XXXII.] THE EARTH'S CENTRAL FLUIDITY QUESTIONED. 21 1 
 
 times, but that they have never been the theatres of such 
 action at any subsequent epoch. On the other hand, we 
 often find that regions where showers of volcanic ashes and 
 the intrusion of igneous matter into fissures were once most 
 frequent, are now entirely free from volcanic disturbance. 
 The continual transfer, therefore, of the points of chief 
 development of the earthquake and volcano from one part 
 of the earth's crust to another, is established as a general 
 law by the clearest geological evidence. We have alsa seen 
 (Chapter XXIII.) that volcanic operations are now in progress 
 on the grandest scale, and also that single currents of lava of 
 modern date are as voluminous as any which can be shown 
 to have ever poured out in the earliest eras to which our 
 geological retrospect can be carried. 
 
 The doctrine, therefore, of the pristine fluidity of the interior 
 of the earth, and the gradual solidification of its crust con- 
 sequent on the loss of internal heat by radiation into space, 
 is one of many scientific hypotheses, which has been adhered 
 to after the props by which it was at first supported have given 
 way one after the other. The astronomer may find good reasons 
 for ascribing the earth's form to the original fluidity of the 
 mass in times long antecedent to the first introduction of living 
 beings into the planet ; but the geologist must be content to 
 regard the earliest monuments which it is his task to inter- 
 pret as belonging to a period when the crust had already 
 acquired great solidity and thickness, probably as great as 
 it now possesses, and when volcanic rocks not essentially dif- 
 fering from those now produced were formed from time to 
 time, the intensity of volcanic heat being neither greater 
 nor less than it is now. This heat has, no doubt, given rise 
 at successive periods to many of the leading changes in the 
 form and structure of the earth's crust ; but their magnitude 
 is by no means such as to warrant our invoking the igneous 
 fusion of the whole planet to account for them. If the 
 reader will refer to the diagram, fig. 128, p. 212, he may 
 convince himself that a machinery more utterly disproportion- 
 ate to the effects which it is required to explain was never 
 appealed to. The outer circular line of the diagram repre- 
 sents a portion of the earth's diameter equal to 25 miles ; so 
 
 p 2 
 
212 THE EARTH'S CENTRAL FLUIDITY QUESTIONED. [On. XXXII. 
 
 that if the loftiest mountain chains, even such as the 
 Himalaya, 5 miles in their greatest height, could be ex- 
 pressed by white marks within this line, they would form a 
 feature in it which would be scarcely appreciable. 
 
 The space between the two circles, including the thickness 
 of the lines themselves, has a breadth or diameter of 200 
 miles. Let us, then, suppose very thin lines 2 inches long, 
 and equal in width to only of the outer line, to be drawn 
 
 Fig. 128. 
 
 Section of the earth in which the breadth of the outer boundary line represents a 
 thickness of 25 miles ; the space between the circles, including the breadth of 
 tke lines, 200 miles. 
 
 here and there within this crust of 200 miles in thickness. 
 These lines, faint and unimportant as they would appear, 
 might nevertheless represent sections of seas or oceans of 
 melted lava 5 miles deep and 5,000 miles long. It can- 
 not be denied that the expansion, melting, solidification 
 and shrinking of such subterranean seas of lava at various 
 depths, might suffice to cause great movements or earth- 
 quakes at the surface, and even great rents in the earth's 
 crust several thousand miles long, such as may be implied 
 
CH. XXXII.] SUPPOSED SECULAR LOSS OF HEAT IN SUN. 213 
 
 by the linearly arranged cones of the Andes or mountain 
 chains like the Alps. 
 
 Supposed secular loss of heat in the solar system. It is a 
 favourite dogma of some physicists, that not only the earth 
 but the sun itself is continually losing a portion of its heat, 
 and that as there is no known source by which it can be 
 restored, we can foresee the time when all life will cease to 
 exist upon this planet, and on the other hand we can look 
 back to the period when the heat was so intense as to be in- 
 compatible with the existence of any organic beings such as 
 are known to us in the living or fossil world. 
 
 When we consider the discoveries recently made of the 
 convertibility of one kind of force into another, and how 
 light, heat, magnetism, electricity and chemical affinity are 
 intimately connected, we may well hesitate before we 
 accept this theory of the constant diminution from age to 
 age of a great source of dynamical and vital power. I shall 
 consider in the next chapter the connection of solar and 
 terrestrial magnetism, and the extent to which electricity 
 may be conceived to be a source of volcanic heat. A geo- 
 logist, in search of some renovating power, by which the 
 amount of heat may be made to continue unimpaired for 
 millions of years, past and future, in the solid parts of the 
 earth, although perpetually shifting the chief points of its 
 development, has been compared by an eminent physicist 
 to one who dreams he can discover a source of perpetual 
 motion, and invent a clock with a self-winding apparatus. 
 But why should we despair of detecting proofs of such a 
 regenerating and self-sustaining power in the works of a 
 Divine Artificer? What is the origin of the force which 
 governs the motions of the heavenly bodies ? It has been 
 likened to the intellectual power of the human will, which 
 initiates and directs all our muscular actions. To define its 
 nature, has hitherto baffled the efforts of the metaphysician 
 and natural philosopher, but assuredly we are not yet so far 
 advanced in our knowledge of the system of the universe as 
 to entitle us to declare that a great dynamical force like that 
 of heat is on the wane. 
 
214 
 
 CHAPTER XXXIII. 
 
 CAUSES OF EARTHQUAKES AND VOLCANOS Continued. 
 
 AGENCY OF STEAM IN VOLCANIC ERUPTIONS GEYSERS OF ICELAND EXPANSIVE 
 
 POWER OF LIQUID GASES ACCESS OF SALT WATER, ATMOSPHERIC AIR, 
 
 AND FRESH WATER TO THE VOLCANIC FOCI HOW THE SUCCESSIVE DEVELOP- 
 MENT OF VOLCANIC HEAT IN THE EARTH'S CRUST CAUSES IT TO RESEMBLE 
 
 A BODY COOLING FROM A GENERAL STATE OF FUSION FLEXIBILITY OF THE 
 EARTH'S CRUST ELECTRICITY AND MAGNETISM CONSIDERED AS SOURCES 01 
 VOLCANIC HEAT CHEMICAL ACTION CAUSES OF PERMANENT ELEVATION AND 
 SUBSIDENCE OF LAND BALANCE OF DRY LAND, HOW PRESERVED RECAPITU- 
 LATION OF CHAPTERS XXII. AND XXIII. 
 
 AGENCY OF STEAM IN VOLCANIC ERUPTIONS.- We have 
 seen that almost all the active volcanos are on sea-coasts or 
 in islands. ' Out of 225 volcanos/ says Sir John Herschel, 
 6 which are known to have been in eruption within the 
 last 150 years, there is only a single instance of one more 
 than 320 miles from the sea, and even that one, Mount 
 Demawend in Persia, is on the edge of the Caspian, the 
 largest of all the inland seas.' Jorullo in Mexico, which was 
 in eruption in 1759, is no less than 120 miles from the nearest 
 ocean ; but, as Dr. Daubeny observes, it forms part of a train 
 of volcanos one extremity of which is near the sea. (See 
 Vol. I. p. 584, and Chap. XXVII. Vol. II. p. 53.) The 
 volcano said to have been in activity in the 7th century 
 in Central Tartaryis 260 geographical miles from the ocean, 
 but near a large lake. (Vol. I. p. 591.) 
 
 Mr. Dana, in his valuable and original observations on the 
 volcanos of the Sandwich Islands, reminds us of the prodigious 
 volume of atmospheric water which must be absorbed into 
 the interior of such large and lofty domes, composed as they 
 are entirely of porous lava. To this source alone he refers 
 the production of the steam by which the melted matter is 
 
CH. XXXIII.] GEYSERS OF ICELAND. 
 
 propelled upwards, even to the summit of cones 3 miles in 
 height.* 
 
 Geysers of Iceland. The extent to which porous rocks are 
 percolated by rain-water to great depths in almost every 
 region, however far from the sea, has been alluded to in our 
 chapter on springs (Vol. I. p. 387) ; and as there is no doubt 
 that ordinary steam plays a prominent part in volcanic 
 eruptions generally, it may be well before going farther to 
 consider attentively a case in which we know it to be exclusively 
 the moving power, namely, that of the Geysers of Iceland. 
 These intermittent hot springs occur in a district situated in 
 the south-western division of Iceland, where nearly 100 of 
 them are said to break out within a circle of 2 miles. That 
 the water is of atmospheric origin, derived from rain and 
 melted snow, is proved, says Professor Bunsen, by the nitrogen 
 which rises from them either pure or mixed with other gases. 
 The springs rise through a thick current of lava, which may 
 perhaps have flowed from Mount Hecla, the summit of that 
 volcano being seen from, the spot at the distance of more 
 than 30 miles. In this district the rushing of water is 
 sometimes heard in chasms beneath the surface ; for here, as 
 on Etna, rivers flow in subterranean channels through the 
 porous and cavernous lavas. It has more than once happened, 
 after earthquakes, that some of the boiling fountains have 
 increased or diminished in violence and volume, or entirely 
 ceased, or that new ones have made their appearance changes 
 which may be explained by the opening of new rents and the 
 closing of pre-existing fissures. 
 
 Few of the Geysers play longer than 5 or 6 minutes at 
 a time, although sometimes half an hour. The intervals 
 between their eruptions are for the most part very irregular. 
 The Great Geyser rises out of a spacious basin at the summit 
 of a circular mound composed of siliceous incrustations de- 
 posited from the spray of its waters. The diameter of this 
 basin, in one direction, is 56 feet, and 46 in another. (See 
 fig. 129.) 
 
 In the centre is a pipe 78 feet in perpendicular depth, 
 
 * Geology of American Exploring Expedition, p. 369. 
 
216 
 
 GEYSERS OF ICELAND. 
 
 [Cn. XXXIII. 
 
 and from 8 to 10 feet in diameter, but gradually widening 
 as it rises into the basin. The inside of the basin is whitish, 
 consisting of a siliceous crust, and perfectly smooth, as are 
 likewise two small channels on the sides of the mound, 
 down which the water escapes when the bowl is filled to the 
 margin. The circular basin is sometimes empty, as repre- 
 sented in the following sketch ; but is usually filled with 
 beautifully transparent water in a state of ebullition. During 
 the rise of the boiling water in the pipe, especially when the 
 
 Fig. 129. 
 
 View of the crater of the Great Geyser in Icelaml. 
 
 ebullition is most violent, and when the water is thrown up 
 in jets, subterranean noises are heard, like the distant firing 
 of cannon, and the earth is slightly shaken. The sound then 
 increases, and the motion becomes more violent, till at length 
 a column of water is thrown up, with loud explosions, to the 
 height of 100 or 200 feet. After playing for a time like an 
 artificial fountain, and giving off great clouds of vapour, 
 the pipe or tube is emptied ; and a column of steam, rushing 
 up with amazing force and a thundering noise, terminates 
 the eruption. 
 
 If stones are thrown into the crater, they are instantly 
 ejected ; and such is the explosive force, that very hard rocks 
 are sometimes shivered by it into small pieces. Henderson 
 found that by throwing a great quantity of large stones into 
 
CH. XXXIII.] AGENCY OF STEAM IN VOLCANOS. 
 
 217 
 
 the pipe of Strockr, one of the Geysers, he could bring on an 
 eruption in a few minutes.* The fragments of stone, as well 
 as the boiling water, were thrown in that case to a much 
 greater height than usual. After the water had been ejected, 
 a column of steam continued to rush up with a deafening 
 roar for nearly an hour ; but the Geyser, as if exhausted by 
 this effort, did not send up a fresh eruption when its usual 
 
 Fig. 130. 
 
 Eruption of the New Geyser in 1810. (Mackenzie.) 
 
 interval of rest had elapsed. The account given by Sir George 
 Mackenzie of a Geyser which he saw in eruption in 1810 
 (see fig. 130), agrees perfectly with the above description 
 by Henderson. The steam and water rose for half an hour 
 to the height of 70 feet, and the white column remained 
 perpendicular notwithstanding a brisk gale of wind which 
 was blowing against it. Stones thrown into the pipe were 
 
 * Journal of a Residence in Iceland, p. 74. 
 
220 GEYSERS OF ICELAND. [<'" XXXIII. 
 
 At the mouth of this tube the water has a temperature, 
 corresponding to the pressure of the atmosphere, of about 
 212 Fahr., but at a certain depth below it is much hotter. This 
 the Professor succeeded in proving by experiment ; a thermo- 
 meter suspended by a string in the pipe rising to 266 Fahr., 
 or no less than 48 above the boiling point. After the 
 column of water has been expelled, what remains in the basin 
 and pipe is found to be much cooled. 
 
 Previously to these experiments of Bunsen andDescloizeaux, 
 made in Iceland in 1846, it would scarcely have been supposed 
 possible that the lower part of a free and open column of 
 water could be raised so much in temperature without causing 
 a circulation of ascending and descending currents, followed 
 by an almost immediate equalisation of heat. Such circula- 
 tion is no doubt impeded greatly by the sides of the well not 
 being vertical, and by numerous contractions of its diameter, 
 but the phenomenon may be chiefly due to another cause. 
 According to experiments on the cohesion of liquids by 
 Mr. Donny of Ghent, it appears that when water is freed 
 from all admixture of air, its temperature can be raised, even 
 under ordinary atmospheric pressure, to 275 Fahr., so much 
 does the cohesion of its molecules increase* when they 
 are not separated by particles of air. As water long boiled 
 becomes more and more deprived of air, it is probably very 
 free from such intermixture at the bottom of the Geysers. 
 
 Among other results of the experiments of Bunsen and his 
 companion, they convinced themselves that the column of 
 fluid filling the tube is constantly receiving accessions of hot 
 water from below, while it becomes cooler above by evapora- 
 tion on the broad surface of the basin. They also came to a 
 conclusion of no small interest, as bearing on the probable 
 mechanism of ordinary volcanic eruptions, namely, that the 
 tube itself is the main seat or focus of mechanical force. 
 This was proved by letting down stones suspended by strings 
 to various depths. Those which were sunk to considerable 
 distances from the surface were not cast up again when the 
 next eruption of the Geyser took place, whereas those nearer 
 
 * See Mr. Horner's Anniversary Address, Quart. Journ. Geol. Soc. 1847, liii. 
 
CH. XXXIII.] AGENCY OF STEAM IN VOLCANOS. 221 
 
 the mouth of the tube were ejected to a height of 100 feet. 
 Other experiments also were made, tending to demonstrate the 
 singular fact, that there is often scarcely any motion below, 
 when a violent rush of steam and water is taking place above. 
 It seems that when a lofty column of water possesses a 
 temperature increasing with the depth, any slight ebullition 
 or disturbance of equilibrium in the upper portion may first 
 force up water into the basin, and then cause it to flow over 
 the edge. A lower portion, thus suddenly relieved of part of 
 its pressure, expands and is converted into vapour more 
 rapidly than the first, owing to its greater heat. This allows 
 the next subjacent stratum, which is much hotter, to rise and 
 flash into a gaseous form ; and this process goes on till the 
 ebullition has descended from the middle to near the bottom 
 of the funnel.* 
 
 In speculating, therefore, on the mechanism of an ordinary 
 volcanic eruption, we may suppose that large subterranean 
 cavities exist at the depth of some miles below the surface of 
 the earth, in which melted lava accumulates; and when 
 water containing the usual mixture of air penetrates into 
 these, the steam thus generated may press upon the lava and 
 force it up the duct of a volcano, in the same manner as a 
 column of water is driven up the pipe of a Geyser. In other 
 cases we may suppose a continuous column of liquid lava 
 mixed with red-hot or white-hot water (for water may exist in 
 that state, as Professor Bunsen reminds us, under pressure), 
 and this column may have a temperature regularly increasing 
 downwards. A disturbance of equilibrium may first bring on 
 an eruption near the surface, by the expansion and conversion 
 into gas of entangled water and other constituents of what 
 we call lava, so as to occasion a diminution of pressure. More 
 steam would then be liberated, carrying up with it jets of 
 melted rock, which being hurled up into the air may fall in 
 showers of ashes on the surrounding country, and at length, 
 by the arrival of lava and water more and more heated at the 
 orifice of the duct or the crater of the volcano, expansive 
 
 * Liebig's Annalen dor Chimie und Memoirs' of Cavendish Soc. London, 
 Pharmacie, translated in ' Reports and 1848, p. 351. 
 
220 GEYSERS OF ICELAND. [Cn. XXXIII. 
 
 At the mouth of this tube the water has a temperature, 
 corresponding to the pressure of the atmosphere, of about 
 212 Fahr., but at a certain depth below it is much hotter. This 
 the Professor succeeded in proving by experiment ; a thermo- 
 meter suspended by a string in the pipe rising to 266 Fahr., 
 or no less than 48 above the boiling point. After the 
 column of water has been expelled, what remains in the basin 
 and pipe is found to be much cooled. 
 
 Previously to these experiments of Bunsen andDescloizeaux, 
 made in Iceland in 1846, it would scarcely have been supposed 
 possible that the lower part of a free and open column of 
 water could be raised so much in temperature without causing 
 a circulation of ascending and descending currents, followed 
 by an almost immediate equalisation of heat. Such circula- 
 tion is no doubt impeded greatly by the sides of the well not 
 being vertical, and by numerous contractions of its diameter, 
 but the phenomenon may be chiefly due to another cause. 
 According to experiments on the cohesion of liquids by 
 Mr. Donny of Ghent, it appears that when water is freed 
 from all admixture of air, its temperature can be raised, even 
 under ordinary atmospheric pressure, to 275 Fahr., so much 
 does the cohesion of its molecules increase* when they 
 are not separated by particles of air. As water long boiled 
 becomes more and more deprived of air, it is probably very 
 free from such intermixture at the bottom of the Geysers. 
 
 Among other results of the experiments of Bunsen and his 
 companion, they convinced themselves that the column of 
 fluid filling the tube is constantly receiving accessions of hot 
 water from below, while it becomes cooler above by evapora- 
 tion on the broad surface of the basin. They also came to a 
 conclusion of no small interest, as bearing on the probable 
 mechanism of ordinary volcanic eruptions, namely, that the 
 tube itself is the main seat or focus of mechanical force. 
 This was proved by letting down stones suspended by strings 
 to various depths. Those which were sunk to considerable 
 distances from the surface were not cast up again when the 
 next eruption of the Geyser took place, whereas those nearer 
 
 * See Mr. Homer's Anniversary Address, Quart. Journ. Greol. Soc. 1847, liii. 
 
CH. XXXIII.] AGENCY OF STEAM IN VOLCANOS. 221 
 
 the mouth of the tube were ejected to a height of 100 feet. 
 Other experiments also were made, tending to demonstrate the 
 singular fact, that there is often scarcely any motion below, 
 when a violent rush of steam and water is taking place above. 
 It seems that when a lofty column of water possesses a 
 temperature increasing with the depth, any slight ebullition 
 or disturbance of equilibrium in the upper portion may first 
 force up water into the basin, and then cause it to flow over 
 the edge. A lower portion, thus suddenly relieved of part of 
 its pressure, expands and is converted into vapour more 
 rapidly than the first, owing to its greater heat. This allows 
 the next subjacent stratum, which is much hotter, to rise and 
 flash into a gaseous form ; and this process goes on till the 
 ebullition has descended from the middle to near the bottom 
 of the funnel.*" 
 
 In speculating, therefore, on the mechanism of an ordinary 
 volcanic eruption, we may suppose that large subterranean 
 cavities exist at the depth of some miles below the surface of 
 the earth, in which melted lava accumulates; and when 
 water containing the usual mixture of air penetrates into 
 these, the steam thus generated may press upon the lava and 
 force it up the duct of a volcano, in the same manner as a 
 column of water is driven up the pipe of a Geyser. In other 
 cases we may suppose a continuous column of liquid lava 
 mixed with red-hot or white-hot water (for water may exist in 
 that state, as Professor Bunsen reminds us, under pressure), 
 and this column may have a temperature regularly increasing 
 downwards. A disturbance of equilibrium may first bring on 
 an eruption near the surface, by the expansion and conversion 
 into gas of entangled water and other constituents of what 
 we call lava, so as to occasion a diminution of pressure. More 
 steam would then be liberated, carrying up with it jets of 
 melted rock, which being hurled up into the air may fall in 
 showers of ashes on the surrounding country, and at length, 
 by the arrival of lava and water more and more heated at the 
 orifice of the duct or the crater of the volcano, expansive 
 
 * Liebig's Annalen der Chimie und Memoirs' of Cavendish Soc. London, 
 Pharmacie, translated in ' Eeports and 1848, p. 351. 
 
222 EXPANSIVE POWER OF LIQUID GASES. [Cn. XXXIII. 
 
 power may be acquired sufficient to expel a massive current 
 of lava. After the eruption lias ceased, a period of tranquil- 
 lity succeeds, during which, fresh accessions of heat are com- 
 municated from below, and additional masses of rock fused 
 by degrees, while at the same time atmospheric or sea water 
 is descending from the surface. At length the conditions 
 required for a new outburst are obtained, and another cycle 
 of similar changes is renewed. 
 
 Expansive power of liquid gases. Although aqueous vapour 
 or steam forms a principal part of the aeriform fluids which 
 rush out for days, months, or even years continuously from 
 volcanic vents, there are other gases, such as the carbonic, 
 sulphurous, and hydrochlorous acids, which are also present, 
 and sometimes in great volume. The experiments of Faraday 
 and others have shown that all these gases may be condensed 
 into liquids by pressure. At temperatures of from 30 to 50 
 Fahr. the pressure required for this purpose varies from 15 
 to 50 atmospheres ; and this amount of pressure we may 
 regard as very insignificant in the operations of nature. A 
 column of Yesuvian lava that would reach from the lip of 
 the crater to the level of the sea, must be equal to about 
 300 atmospheres ; so that, at depths which may be termed 
 moderate Jin the interior of the crust of the earth, the gases 
 may be condensed into liquids, even at very high tempera- 
 tures. The method employed to reduce some of these gases 
 to a liquid state is, to confine the materials, from the mutual 
 action of which they are evolved, in tubes hermetically sealed, 
 so that the accumulated pressure of the vapour, as it rises 
 and expands, may force some part of it to assume the liquid 
 state. A similar process may, and indeed must, frequently 
 take place in subterranean caverns and fissures, or even in 
 the pores and cells of many rocks ; by which means, a much 
 greater store of expansive power may be packed into a small 
 space than could happen if these vapours had not the pro- 
 perty of becoming liquid. For, although the gas occupies 
 much less room in a liquid state, yet it exerts exactly the 
 same pressure upon the sides of the containing cavity as if it 
 remained in the form of vapour. 
 
 If a tube, whether of glass or other materials, filled with 
 
CH. XXXIII.] EXPANSIVE POWER OF LIQUID GASES. 223 
 
 condensed gas, have its temperature slightly raised, it will 
 often burst ; for a slight increment of heat causes the 
 elasticity of the gas to increase in a very high ratio. If a 
 minute hole be bored in the tube, the liquid gas will become 
 instantly aeriform, or, in the language of some writers, it 
 flashes into vapour, and in rushing out often bursts the 
 vessel. We have only to suppose certain rocks, permeated by 
 these liquid gases (as porous strata are sometimes filled with 
 water), to have their temperature raised some hundred 
 degrees, and we obtain a power capable of lifting superin- 
 cumbent masses of almost any conceivable thickness ; while, 
 if the depth at which the gas is confined be great, there is 
 no reason to suppose that any other appearances would be 
 witnessed by the inhabitants at the surface than vibratory 
 movements and rents, since the gases, in making their way 
 through fissured rocks or soft yielding strata, may be cooled 
 and absorbed by water. For water has a strong affinity to 
 several of the gases, and will absorb large quantities, with a 
 very slight increase of volume. In such cases there may be 
 no outburst at the surface, nor any obvious indication of 
 subterranean change. The temperature, perhaps, or volume 
 of springs may be augmented, and their mineral proper- 
 ties altered, but no volcanic explosion may be witnessed. 
 Whether a permanent change of level may be expected to 
 occur as a consequence or accompaniment of such gene- 
 ration and heating of gases in the interior of the earth's 
 crust, will be considered in the sequel. 
 
 The volcano of Cotopaxi has been known to throw out, to 
 the distance of 8 or 9 miles, a mass of rock about 100 cubic 
 yards in volume, and there is no difficulty in understanding 
 how the most solid substances which oppose the upward 
 passage of the exploding gases may be reduced to small 
 fragments, or even to dust, such as we see hurled to the 
 height of many miles into the air by the volcano. 
 
 Access of salt water to the volcanic foci. Although the 
 theory which assumes that water plays a principal part in 
 volcanic operations does not necessarily imply the proximity 
 of volcanic vents to the ocean, it seems still to follow naturally 
 that the superficial outbursts of steam and lava will be most 
 
224 ACCESS OF SALT WATER TO VOLCANIC FOCI. [Cn. XXXIIL 
 
 prevalent where there is an incumbent body of salt water, or 
 in any regions rather than in the interior of a continent, where 
 the quantity of rain-water is reduced to a minimum. The 
 experiments and observations of the most eminent chemists 
 have gradually removed, one after another, the objections 
 which were first offered to the doctrine that the salt water 
 of the sea plays a leading part in most volcanic eruptions. 
 Sir H. Davy observed that the fumes which escaped from the 
 Vesuvian lava deposited common salt.* 
 
 M. Gay-Lussac, although he avowed his opinion that the 
 decomposition of water contributed largely to volcanic action, 
 called attention, nevertheless, to the supposed fact, that 
 hydrogen had not been detected in a separate form among 
 the gaseous products of volcanos ; nor could it, he said, be 
 present ; for, in that case, it would be seen inflamed in the 
 air by the red-hot stones thrown out during an eruption.f 
 
 But M. Abich remarked, on the other hand, c that although 
 it be true that vapour illuminated by incandescent lava 
 has often been mistaken for flame,' yet he had clearly 
 detected the flame of hydrogen in the eruption of Vesuvius 
 in 18344 
 
 In the memoir just alluded to, M. Gay-Lussac expressed 
 doubt as to the presence of sulphurous acid ; but the abun- 
 dant disengagement of this gas during eruptions has been 
 since ascertained: and thus all difficulty in regard to the 
 general absence of hydrogen in an inflammable state is 
 removed ; for, as Dr. Daubeny suggests, the hydrogen of 
 decomposed water may unite with sulphur to form sulphu- 
 retted hydrogen gas, and this gas will then be mingled with 
 the sulphurous acid as it rises to the crater. It is shown 
 by experiment, that these gases mutually decompose each 
 other when mixed where steam is present ; the hydrogen of 
 the one immediately uniting with the oxygen of the other 
 to form water, while the excess of sulphurous acid alone 
 escapes into the atmosphere. Sulphur is at the same time 
 precipitated. 
 
 * Davy, Phil. Trans. 1828, p. 244. 
 
 t Ann. de Chim. et de Phys. torn. xxii. 
 
 j Phenom. Greol. &c. p. 3. 
 
CH. XXXIII. ] ESCAPE OF HYDROGEN DURING- ERUPTIONS. 225 
 
 This explanation is sufficient ; but it may also be observed 
 that the flame of hydrogen would rarely be visible during an 
 eruption ; as that gas, when inflamed in a pure state, burns 
 with a very faint blue flame, which even in the night could 
 hardly be perceptible by the side of red-hot and incandes- 
 cent cinders. Its immediate conversion into water when 
 inflamed in the atmosphere, might also account for its not 
 appearing in a separate form. 
 
 The observations of Bunsen in Iceland in 1844, of St. 
 Claire Deville on Vesuvius in 1855 and 1861, and of Fouque 
 on Santorin in 1866, have proved that there is an abundant 
 escape of hydrogen, both in a free state and in combination 
 with other substances, during eruptions ; and the two last- 
 mentioned chemists have succeeded in demonstrating the 
 perfect accordance of the chemical composition of the pro- 
 ducts of volcanic eruptions, both gaseous and solid, with the 
 doctrine that salt water has been largely present in the vol- 
 canic foci. It had been asked why then are there no salts of 
 magnesia in volcanic fumeroles ? They reply that these salts 
 are readily decomposable by hot steam, and that when water 
 and heat are present they produce hydrochloric acid and 
 magnesia. That acid is found in the vapours which are 
 disengaged from red-hot lava, and the magnesia which is 
 not volatile is left behind in the lava itself, constituting one 
 of its most important elements.* In like manner, the last- 
 mentioned French chemists have shown that common salt 
 can be resolved into its elements by hot steam alone, which 
 Gay-Lussac had thought impossible. 
 
 M. Fouque aflirms that in the recent eruption of Etna 
 (in 1865) which he witnessed, the gaseous emanations agreed 
 in kind with those which we might have looked for if large 
 bodies of sea-water had gained access to reservoirs of sub- 
 terranean lava, and if they had been decomposed and ex- 
 pelled with the lava ; and more than this, he calculated that 
 the quantity of aqueous vapour was relatively to other gases 
 in due proportion that there was a daily emission from 
 
 * Fouqxie, Rapport sur les Phenomenes Chimiques. Eruption of Etna in 1865, 
 p. 57. 
 
 VOL. II. Q 
 
226 EARTH'S CRUST A BODY COOLING FROM FUSION. [Cn. XXXIII. 
 
 the several vents which were open on Etna, of no less than 
 22,000 cubic metres of aqueous vapour. 
 
 Access of atmospheric air and fresh water to the volcanic 
 foci. The presence of nitrogen among the gases evolved 
 from craters in eruption, and in the waters of thermal 
 springs, has been another subject of enquiry and discussion. 
 
 Sir H. Davy, in his memoir on the ( Phenomena of Vol- 
 canos,' remarks, that there was every reason to suppose in 
 Vesuvius the existence of a descending current of air ; and 
 he imagined that subterranean cavities which threw out 
 large volumes of steam during the eruption, might after- 
 wards, in the quiet state of the volcano, become filled with 
 atmospheric air.* The presence of ammoniacal salts in 
 volcanic emanations, and of ammonia (which is in part com- 
 posed of nitrogen) in lava, favours greatly the notion of 
 air as well as water being deoxidated in the interior of 
 the earth. f 
 
 Dr. Daubeny suggests that water containing atmospheric 
 air may descend from the surface of the earth to the 
 volcanic foci, and that the same process of combustion by 
 which water is decomposed may deprive such subterranean 
 air of its oxygen. In this manner great quantities of nitro- 
 gen may be evolved. 
 
 The presence of vast numbers of siliceous cases of infu- 
 soria in the tuff covering Pompeii, and composed of matter 
 ejected from Vesuvius and other volcanos, has already been 
 alluded to. (Yol. I. p. 644.) They prove that water and 
 mud have penetrated downwards from the surface into rents 
 and caverns in the interior, and have then been thrown out 
 again during volcanic eruptions. 
 
 The earth's crust a body cooling from a state of fusion. What 
 we have now said of the manner in which aqueous and other 
 gases may be expected to operate mechanically and chemi- 
 cally 011 the crust of the earth, whenever water and various 
 acids, stored up in caverns and fissures at great depths, have 
 their temperatures raised, must satisfy the reader that it is 
 only necessary, in order to explain the action of volcanos, 
 
 * Phil. Trans. 1828. 
 
 f See Daubeny, Encyc. Metrop. Part 40. 
 
CH. XXXIII.] FLEXIBILITY OF THE EAETH'S CRUST. 227 
 
 to discover some cause which, is capable of bringing about 
 such a concentration of heat as may melt, one after the 
 other, certain portions of the solid crust so as to form seas, 
 lakes, or oceans of subterranean lava. This being granted, 
 the greater part of the crust at any given time will contain 
 at various depths sheets of such lava slowly parting with 
 their heat some semi-fluid, others more or less viscous, and 
 others beginning to consolidate or crystallise. The general 
 state, therefore, of the exterior of the planet would be that of 
 a mass once heated, and which has been gradually cooling ; 
 but in certain spots, namely the regions of active volcanos, 
 regions very limited and exceptional as regards the whole 
 surface, the heat will be on the increase, and will occasion- 
 ally manifest its intensity in the operations of the volcano 
 and the earthquake. 
 
 That beneath the Andes and other great areas of active 
 volcanos there are reservoirs, at the depth of some miles, 
 of lava in a constant state of fusion, cannot be doubted from 
 what we have already stated (pp. 90 and 202). All the observed 
 phenomena from which the existence of central fluidity has 
 been inferred are reconcilable with the occurrence at certain 
 depths of such masses of lava in the earth's crust as we 
 have admitted to be probable, and which, even if they 
 equalled the Atlantic and Pacific Oceans in volume, may 
 hold a very subordinate place in the solid shell of the planet. 
 The connection of earthquakes with a flexible crust overlying 
 such reservoirs of melted rock is quite conceivable. 
 
 Flexibility of the earth's crust. The inhabitants of Strom- 
 boli, who are mostly fishermen, are said to make use of that 
 volcano* as a weather-glass, the eruptions being comparatively 
 feeble when the sky is serene, but increasing in turbulence 
 during tempestuous weather, so that in winter the island 
 often seems to shake from its foundations. Mr. P. Scrope, 
 after calling attention to these and other analogous facts, 
 first started the idea (as long ago as the year 1825) that the 
 diminished pressure of the atmosphere, the concomitant of 
 stormy weather, may modify the intensity of the volcanic 
 action. He suggests that where liquid lava communicates 
 with the surface, as in the crater of Stromboli, it may rise 
 
 Q2 
 
228 FLEXIBILITY OF THE EARTH'S CRUST. [Cn. XXXIII. 
 
 or fall in the vent on the same principle as mercury in a 
 barometer ; because the ebullition or expansive power of the 
 steam contained in the lava would be checked by every 
 increase, and augmented by every diminution of weight. 
 In like manner, if a bed of liquid lava be confined at an 
 immense depth below the surface, its expansive force may be 
 counteracted partly by the weight of the incumbent roc's, 
 and also in part by atmospheric pressure adting contem- 
 poraneously on a vast superficial area. In that case, if the 
 upheaving force increase gradually in energy, it will at 
 length be restrained by only the slightest degree of supe- 
 riority in the antagonist or repressive power, and then the 
 equilibrium may be suddenly destroyed by any cause, such 
 as an ascending draught of air, which is capable of depressing 
 the barometer. In this manner we may account for the 
 remarkable coincidence so frequently observed between the 
 state of the weather and subterranean commotions, although 
 it must be admitted that earthquakes and volcanic eruptions 
 react in their turn upon the atmosphere, so that disturbances 
 of the latter are generally the consequences rather than the 
 forerunners of volcanic disturbances.* 
 
 From an elaborate catalogue of the earthquakes experienced 
 in Europe and Syria during the last fifteen centuries, M. 
 Alexis Perrey concludes that the number which happen in 
 the winter season preponderates over those which occur in 
 any one of the other seasons of the year, there being, how- 
 ever, some exceptions to this rule, as in the Pyrenees. 
 Curious and valuable as are these data, M. d'Archiac justly 
 remarks, in commenting upon them, that they are not as yet 
 sufficiently extensive or accordant in different regions, to 
 entitle us to deduce any general conclusions from them 
 respecting the laws of subterranean movements throughout 
 the globe.f 
 
 M. Perrey has also, in a later report of earthquakes (1863), 
 inferred, as the result of 10,000 observations on the earth- 
 quakes of the first half of the present century, that they 
 occur more frequently and with more violence when the 
 
 * Scrope on Volcanos, pp. 58-60. 
 
 t Archiac, Hist, des Progr&s de la Greol. 1847, vol. i. pp. 605-610. 
 
CH. XXXIII.] FLEXIBILITY OF THE EARTH'S CRUST. 229 
 
 inoon is in perigee, or nearest the earth, than at other periods, 
 when that satellite being less near is exerting a minor degree 
 of force, or less strain upon the solid crust of our planet. In 
 like manner he thinks he has detected a relation between the 
 frequency of earthquakes and our winter and summer solstices, 
 the greatest number of shocks occurring in perihelion when 
 the sun is nearest, and the least number in aphelion when 
 it is farthest from the earth.* On this subject Sir John 
 Herschel remarks, c The action of the sun and moon, though 
 it cannot produce a tide in the solid crust of the earth, tends 
 to do so, and were it fluid would produce it. It does there- 
 fore, in point of fact, bring the solid portions of the earth's 
 surface into a state alternately of strain and compression.' t 
 Sir John Herschel, when endeavouring to suggest a cause 
 for the frequent proximity of chains of active volcanos, like 
 the Andes, to the sea, assumes that the solid bottom of the 
 latter and the neighbouring land may be regarded as float- 
 ing on a subterranean fluid mass. The land, he observes, is 
 always undergoing waste by aqueous action, and portions of 
 its solid matter are carried down in the form of sediment into 
 the sea. By this means the bed of the ocean is pressed 
 down, while the continent is relieved of pressure, and this 
 brings about a state of strain in the crust which will crack 
 in its weakest part, the heavy side going down, and the light 
 side rising. The subterranean fiery matter will then burst 
 out through the rent, as water oozes up when a crack 
 takes place in the ice.J This hypothesis appears to me of 
 very partial application, for active volcanos, even such as 
 are on the borders of continents, are rarely situated where 
 great deltas have been forming, whether in pliocene or post- 
 tertiary times. The number, also, of active volcanos in 
 oceanic islands is very great, not only in the PaciHc, but 
 equally in the Atlantic, where no load of coral matter or any 
 sedimentary deposits derived from the waste of neighbouring 
 lands can cause a partial weighting and pressing down of 
 a supposed flexible crust. 
 
 * Alexis Perrey, Propositions sur les Scientific Subjects, 1866, p. 45. 
 Tremblements de Terre, 1863. J Herschel, ibid. p. 12. 
 
 f Herschel, Familiar Lectures on 
 
230 ELECTRICITY AND MAGNETISM CONSIDERED [Cir. XXXIII- 
 
 Electricity and magnetism considered as sources of volcanic 
 heat. The popular notion of a central fluid nucleus, on which, 
 a thin outer shell is floating, has diverted the speculations 
 of the physicist and natural philosopher from attempting 
 to invent some theory which might explain the continual 
 shifting of the points of the chief development of heat from 
 one part of the shell to another, leaving large portions 
 previously in a state of fusion to cool and consolidate. 
 Soon after the first great discoveries of Oersted in electro- 
 magnetism, Ampere suggested that all the phenomena of the 
 magnetic needle might be explained by supposing currents 
 of electricity to 'circulate constantly in the shell of the globe 
 in directions parallel to the magnetic equator. This 
 theory has acquired additional consistency the farther we 
 have advanced in science; and according to the experiments of 
 Mr. Fox, on the electro-magnetic properties of metalliferous 
 veins, some trace of electric currents seems to have been 
 detected in the interior of the earth. * 
 
 Some philosophers ascribe these currents to the chemical 
 action going on in the superficial parts of the globe to which 
 air and water have the readiest access ; while others refer 
 them, in part at least, to thermo-electricity excited by the 
 solar rays on the surface of the earth during its rotation ; 
 successive parts of the atmosphere, land, and sea being ex- 
 posed to the influence of the sun, and then cooled again in 
 the night. That this idea is not a mere speculation, is 
 proved by the correspondence of the diurnal variations of the 
 magnet with the apparent motion of the sun ; and by the 
 greater amount of variation in summer than in winter, and 
 during the day than in the night. 
 
 Allusion was made in the first volume (p. 303) to the recent 
 discovery of a connection between periodical changes in the 
 spots of the sun and variations in terrestrial magnetism, 
 suggesting the idea that solar magnetism has a powerful 
 influence on the earth's crust. According to Sir John 
 Herschel, the cycle of change, including the periods when 
 the spots are most abundant and large, and those when they 
 are least apparent, occupies rather more than 11 years, 
 
 * Phil. Trans. 1830, p. 399. 
 
Cn. XXXIII.] AS SOURCES OF VOLCANIC HEAT. 23 1 
 
 so that there are 9 of these cycles in a century. So late 
 as September 1, 1859, when the spots were very large, 'two 
 observers, far apart and unknown to each other, were viewing 
 them with powerful telescopes, when suddenly, at the same 
 moment of time, both saw a strikingly brilliant luminous 
 appearance, like a cloud of light, far brighter than the general 
 surface of the sun, break out in the immediate neighbourhood 
 of one of the spots, and sweep across and beside it. It occu- 
 pied about five minutes in its passage, and in that time 
 travelled over a space on the sun's surface which could not 
 be estimated at less than 35,000 miles. A magnetic storm 
 was in progress at the time. From August 28 to September 4 
 many indications showed the earth to have been in a perfect 
 convulsion of electro-magnetism.' 
 
 At Kew, where there are self-registering magnetic instru- 
 ments, by which the positions of three magnetic needles are 
 recorded by photography, it was found that all three had 
 made a strongly marked jerk from their former positions at 
 the very moment when the bright light had been seen crossing 
 the solar spot. It would appear that the magnetic influence 
 had reached the earth at the same time with the light. 
 
 6 By degrees, accounts began to pour in of great Auroras 
 seen on the nights of those days, not only in these latitudes, 
 but at Rome, in the West Indies, on the tropics within 18 
 of the equator (where they hardly ever appear), nay, what is 
 still more striking, in South America and in Australia, where, 
 at Melbourne, on the night of the 2nd of September, the 
 greatest Aurora ever seen there made its appearance. These 
 Auroras were accompanied with unusually great electro- 
 magnetic disturbances in every part of the world. In many 
 places the telegraphic wires struck work. At Washington 
 and Philadelphia, in America, the telegraph signal-men 
 received severe electric shocks. At a station in Norway the 
 telegraphic apparatus was set fire to ; and at Boston, in 
 North America, a flame of fire followed the pen of Bain's 
 electric telegraph, which writes down the message upon 
 chemically prepared paper.' * 
 
 * Herschel, Familiar Lectures on Scientific Subjects, 1 866, p. 80. 
 
232 ELECTRICITY A SOUECE OF VOLCANIC HEAT. [Cu. XXXIII. 
 
 The passage of this electro-magnetic force from the sun to 
 our globe may, perhaps, be one of the principal means by 
 which heat lost by conduction into space may be restored to 
 the planet ; and we may easily imagine that at successive 
 geological periods, when new mountain chains have been 
 thrown up and old ones have been removed by subsidence or 
 denudation, when even oceans and continents have changed 
 places, the circulation of electro-magnetic currents and the 
 local concentration of heat due to them may affect new parts 
 of the exterior of the planet. It is scarcely possible to exag- 
 gerate the amount of action and reaction to which the cause 
 here alluded to may give rise. ' The silent and slow operation 
 of electricity as a chemical agent is more important,' says 
 Davy, ' in the economy of nature than its grand and impressive 
 operation in lightning and thunder. It may be considered, 
 not only as directly producing an infinite variety of changes, 
 but as influencing almost all which take place ; it would 
 seem, indeed, that chemical attraction itself is only a peculiar 
 form of the exhibition of electrical attraction.' * 
 
 Thermo-electricity may be generated by great inequalities 
 of temperature, arising from a partial distribution of volcanic 
 heat. Wherever, for example, masses of rock occur of great 
 horizontal extent, and of considerable depth, which are at 
 one point in a state of fusion (as beneath some active volcano); 
 at another, red-hot; and at a third, comparatively cold 
 strong thermo-electric action may be excited, and subterra- 
 nean electric currents, if once excited, may melt rock or 
 possess the decomposing power of the voltaic pile. 
 
 Chemical action. When Sir H. Davy first discovered the 
 metallic bases of the earths and alkalies, he threw out the 
 idea that stores of those metals might abound in an un- 
 oxidised state in the subterranean regions to which water 
 must occasionally penetrate. Whenever this happened, 
 gaseous matter would be set free, the metals would combine 
 with the oxygen of the water, and sufficient heat might be 
 evolved to melt the surrounding rocks. This hypothesis was 
 at first very favourably received both by the chemist and the 
 
 * Consolations in Travel, p. 271. 
 
CH. XXXIII.] CHEMICAL ACTION. 233 
 
 geologist : for silica, alumina, lime, soda, and oxide of iron 
 substances of which lavas are principally composed 
 would all result from the contact of the inflammable metals 
 alluded to with water. But when Davy failed to detect, 
 during an eruption of Yesuvius, a,ny hydrogen among the 
 gaseous products evolved from the crater, he was disposed to 
 renounce or to attach but little importance to his theory. 
 
 We have seen (p. 225) that it is now ascertained that hydro- 
 gen is disengaged during eruptions in large quantities ; but, 
 according to M. Fouque, there is always much more proto- 
 carbonate of hydrogen than free hydrogen, whereas the 
 reverse ought to be the case, if these combustible gases 
 resulted from the contact of alkaline metals with water.* 
 The same chemist remarks, that to explain the disengagement 
 of heat during the last eruption of Etna, we should require 
 a mass of sodium of at least 7,000,000 cubic metres, and 
 therefore the quantity of alkaline metals beneath all the 
 active volcanos, which has given rise in each to a long series 
 of eruptions, would be incredibly great. 
 
 M. Fouque is satisfied with the hypothesis of a subterranean 
 sheet of fluid lava, to which water occasionally may gain 
 access, central heat being invoked as the power by which 
 the lower parts of the earth's crust are retained in a melted 
 state, and no explanation being attempted by him of the 
 shifting of the volcanic force from one part of the earth's 
 envelope to another. 
 
 In former editions, I have suggested that if the accumu- 
 lation of heat be granted as successively developed in 
 different parts of the earth's shell, we may readily conceive 
 that the waters of lakes and seas might gain access to the 
 fluid lava during earthquakes, large bodies of water being 
 occasionally engulfed, and then, when the sides of the 
 fissures closed again with violence (see page 125), the steam 
 generated by contact of the water with the heated subterra- 
 nean fluid, would not escape by the same rents, but might 
 rush out with lava from some distinct and perhaps habitual 
 
 * Fouque, Rapport sur les Phenomenes Chimiques de 1'Eruption de 1'Etna 
 en 1865, p. 80. 
 
234 CAUSES OF PERMANENT ELEVATION [On. XXXIII. 
 
 volcanic openings. That there should be so much heat and 
 chemical action and reaction, developed in certain parts of 
 the interior of the earth, is not so wonderful as the ordinary 
 repose and inertness of the internal mass. When we con- 
 sider the combustible nature of the elements of the earth, so 
 far as they are known to us the facility with which their 
 compounds may be decomposed and made to enter into new 
 combinations the quantity of heat which they evolve 
 during these processes; when we recollect the expansive 
 power of steam, and that water itself is composed of two 
 gases which, by their union, produce intense heat ; when we 
 call to mind the number of explosive and detonating com- 
 pounds which have been already discovered, we may be 
 allowed to share the astonishment of Pliny, that a single day 
 should pass without a general conflagration : ' Excedit 
 profecto omnia miracula, ullum diem fuisse quo non cuncta 
 conflagrarent.' * 
 
 But the difficulties we encounter when we attempt to form 
 a chemical theory of volcanos, are almost insurmountable, in 
 consequence of our inability to test experimentally the mode 
 in which different substances, solid, fluid, or gaseous, would 
 behave under conditions of pressure and temperature wholly 
 different from those experienced at the surface. A simple 
 difference in the amount of heat may, observes Ssemann, 
 cause all the chemical affinities of bodies to be essentially 
 modified. Mercury, he remarks, ' does not combine with 
 oxygen at ordinary temperatures, but combines with it at its 
 boiling point, and then gives it off again at an incipient red 
 heat. Here we have three different states of chemical affinity 
 within the limits of a few hundred degrees ; and who would 
 dare assert, that at this last phase of separation, the chemical 
 action between these two elements ceases definitely and for 
 all higher temperatures? But what is true of mercury and 
 oxygen, is likewise true for all other elements. 'f 
 
 Causes of permanent elevation and subsidence of land. The 
 position of the fossiliferous and other rocks in the earth's 
 
 * Hist. Mundi, lib. ii. c. 107- 
 
 f Louis Ssemann, Notes on Daubree on Meteorites, Genl. Mag. 1866, p. 362. 
 
CH. XXXIII.] AND SUBSIDENCE OP LAND. 235 
 
 crust, has enabled the geologist to infer that some of these 
 rocks have been lifted up to the height of several miles above 
 the level at which they were originally formed in the bed of 
 the ocean, and also that there have been gradual subsidences 
 of rocks to a vast amount below the levels which they once 
 occupied. These great movements have been caused by 
 subterranean or volcanic heat, which has affected different 
 parts of the earth in succession. The existing mountain 
 chains are of different ages, and few of them owe the whole 
 of their present conformation to the movements experienced 
 in a single epoch. The forces, whether in an upward or 
 downward direction, to which they are due, and by which the 
 varying position of continents and oceanic basins has in the 
 course of ages been determined, have evidently shifted their 
 points of chief development from one region to another, like 
 the volcano and the earthquake, and are in fact all the 
 results of the same internal operations, to which heat, 
 electricity, magnetism, and chemical affinity give rise. 
 
 Experiments were made in America, by Colonel Totten, to 
 ascertain the ratio according to which some of the stones 
 commonly used in architecture expand with given increments 
 of heat.* It was found impossible, in a country where the 
 annual variation of temperature was more than 90 Fahr., to 
 make a coping of stones, 5 feet in length, in which the 
 joints should fit so tightly as not to admit water between 
 the stone and the cement; the annual contraction and 
 expansion of the stones causing, at the junctions, small 
 crevices, the width of which varied with the nature of the 
 rock. It was ascertained that fine-grained granite expanded 
 with 1 Fahr. at the rate of -000004825 ; white crystalline 
 marble -000005668 ; and red sandstone -000009532, or about 
 twice as much as granite. 
 
 Now, according to this law of expansion, a mass of sand- 
 stone, a mile in thickness, which should have its temperature 
 raised 200 Fahr. would lift a superimposed layer of rock to 
 the height of 10 feet above its former level. But, suppose a 
 part of the earth's crust, 50 miles in thickness and equally 
 
 * Silliman's American Journ. vol. results to the theory of earthquakes was 
 xxii. p. 136. The application of these first suggested to me by Mr. Babbage. 
 
23G ELEVATION AND SUBSIDENCE OF LAND. [Cn. XXXIII. 
 
 expansible, to have its temperature raised 600 or 800, tliis 
 might produce an elevation of between 1,000 and 1,500 feet. 
 The cooling of the same mass might afterwards cause the 
 overlying rocks to sink down again and resume their original 
 position. By such agency we might explain the gradual 
 rise of part of Scandinavia or the subsidence of Greenland. 
 
 It is also possible that as the clay in Wedgwood's pyro- 
 meter contracts, by giving off its water, and then, by inci- 
 pient vitrification ; so, large masses of argillaceous strata in 
 the earth's interior may shrink, when subjected to heat and 
 chemical changes, and allow the incumbent rocks to subside 
 gradually. 
 
 Moreover, if we suppose that lava cooling slowly at great 
 depths may be converted into various granitic rocks, we 
 obtain another source of depression ; for, according to the 
 experiments of Deville and the calculations of Bischoff, the 
 contraction of granite when passing from a melted or plastic 
 to a solid and crystalline state must be more than 10 per cent.* 
 
 Dr. Bischoff has also remarked, that when the silicates 
 which enter so largely into the composition of the oldest rocks 
 gneiss, mica-schist, clay-slate, and others are percolated 
 by carbonic acid gas, which is of almost universal occurrence 
 at great depths, they must be continually decomposed. When 
 that happens, the carbonates formed by the new combinations 
 thence arising must often augment the volume of the altered 
 rocks. This increase of bulk, he says, must sometimes give 
 rise to a mechanical force of expansion capable of uplifting 
 the incumbent crust of the earth, and the same force may act 
 laterally, so as to compress, dislocate, and tilt the strata on 
 each side of a mass in which the new chemical changes are 
 developed. The same eminent German chemist has attempted 
 to calculate the exact amount of distension to which the new 
 mineral products thus formed may give rise by adding to the 
 volume of the rocks. 
 
 If once some parts of the earth's crust are shattered, as in 
 regions of earthquakes, and reservoirs of melted stone and 
 heated vapours have acquired force enough to uplift the 
 
 * Bulletin de la Soc. Greol. 2nd series, vol. iv. p. 1312. 
 
CH. XXXIII.] PRESERVATION OF BALANCE OF DRY LAND. 237 
 
 incumbent mass, we may easily conceive how the country 
 may remain permanently upheaved. For in some places the 
 fractured rocks below may have assumed an arched form, or 
 lava may have been driven into fissures, in which it may 
 consolidate, and afford an enduring support to the foun- 
 dations of the newly raised strata. 
 
 The sudden subsidence of limited areas of land may be 
 occasioned by subterranean caverns giving way, when gases 
 are condensed, or when they escape through newly-formed 
 crevices. The subtraction, moreover, of matter from certain 
 parts of the interior, by the flowing of lava, and of mineral 
 springs, must, in the course of ages, cause vacuities below, 
 so that the undermined surface may at length fall in or be 
 slowly depressed. In this manner we may, perhaps, explain 
 the geographical connection which seems to exist between 
 areas of elevation and of subsidence, a deep sea being often 
 contiguous to elevated land. 
 
 Balance of dry land, how preserved. It will appear, from the 
 historical details above given, that the force of subterranean 
 movement, whether intermittent or continuous, whether with 
 or without disturbance, does not operate at random, but is 
 developed in certain regions only ; and although the altera- 
 tions produced during the time required for the occurrence 
 of a few volcanic eruptions may be inconsiderable, we can 
 hardly doubt that, during the ages necessary for the for- 
 mation of large volcanic cones, composed of thousands of 
 lava currents, shoals might be converted into lofty mountains, 
 and low lands into deep seas. 
 
 In a former chapter (Vol. I. p. 327), I have stated that 
 aqueous and igneous agents may be regarded as antagonist 
 forces ; the aqueous labouring incessantly to reduce the in- 
 equalities of the earth's surface to a level, while the igneous 
 are equally active in renewing the unevenness of the surface. 
 By some geologists it has been thought that the levelling 
 power of running water was opposed rather to the elevating 
 force of earthquakes than to their action generally. This 
 opinion is, however, untenable ; for the sinking down of the 
 bed of the ocean is one of the means by which the gradual 
 submersion of land is prevented. The depth of the sea cannot 
 
238 PRESERVATION OF BALANCE OF DRY LAND. [On. XXXIII. 
 
 be increased at any one point without a universal fall of the 
 waters, nor can any partial deposition of sediment occur 
 without the displacement of a quantity of water of equal 
 volume, which will raise the sea, though in an imperceptible 
 degree, even to the antipodes. The preservation, therefore, 
 of the dry land may sometimes be effected by the subsidence 
 of part of the earth's crust (that part, namely, which is 
 covered by the ocean), and in like manner an upheaving 
 movement must often tend to destroy land ; for if it render 
 the bed of the sea more shallow, it will displace a certain 
 quantity of water, and thus tend to submerge low tracts. 
 
 If the dimensions of the planet have remained uniform 
 during the period which we contemplate in geology, it would 
 be necessary to suppose that the amount of depression caused 
 by subterranean heat must exceed that of elevation, otherwise 
 there would not be a perpetual restoration of those inequa- 
 lities of the earth's surface which the levelling power of 
 water tends to efface. It would be otherwise if the action of 
 volcanos and mineral springs were suspended; for then 
 the forcing outwards of the earth's envelope ought to be no 
 more than equal to its sinking in. 
 
 To understand this proposition more clearly, it must be 
 borne in mind, that the deposits of rivers and currents 
 probably add as much to the height of lands which are 
 rising, as they take from those which have risen. Suppose 
 a large river to bring down sediment to a part of the ocean 
 2,000 feet deep, and that the depth of this part is gradually 
 reduced by the accumulation of sediment till only a shoal 
 remains, covered by water at high tides ; if now an upheaving 
 force should uplift this shoal to the height of 2,000 feet, the 
 result would be a mountain 2,000 feet high. But had the 
 movement raised the same part of the bottom of the sea 
 before the sediment of the river had filled it up; then, 
 instead of changing a shoal into a mountain 2,000 feet high, 
 it would only have converted a deep sea into a shoal. 
 
 It appears, then, that the operation of the volcanic or 
 subterranean forces is often such as to cause the levelling 
 power of water to counteract itself; and, although the idea 
 may appear paradoxical, we may be sure, wherever we find 
 
CH. XXXIII.] PRESEKVATION OF BALANCE OF DEY LAND. 239 
 
 hills and mountains composed of stratified deposits, that 
 such inequalities of the surface would have had no existence 
 if water, at some former period, had not been labouring to 
 reduce the earth's surface to one level. 
 
 But, besides the transfer of matter by running water from 
 the continents to the ocean, there is a constant transporta- 
 tion from below upwards, by mineral springs and volcanic 
 vents. As mountain masses are, in the course of ages, 
 created by the pouring forth of successive streams of lava, so 
 stratified rocks of great extent originate from the deposition 
 of carbonate of lime, and other mineral ingredients, with 
 which springs are impregnated. The surface of the land, 
 and portions of the bottom of the sea, being thus raised, the 
 external accessions due to these operations would cause the 
 dimensions of the planet to enlarge continually, if the amount 
 of depression of the earth's crust were no more than equal to 
 the elevation. In order, therefore, that the mean diameter 
 of the earth should remain uniform, and the unevenness of 
 the surface be preserved, it is necessary that the amount of 
 subsidence should be in excess. And such a predominance 
 of depression is far from improbable, on mechanical prin- 
 ciples, since every upheaving movement must be expected 
 either to produce caverns in the mass below, or to cause some 
 diminution of its density. Vacuities must, also, arise from 
 the subtraction of the matter poured out from volcanos and 
 mineral springs, or from the contraction of argillaceous 
 masses by subterranean heat ; and the foundations having 
 been thus weakened, the earth's crust, shaken and rent by 
 reiterated convulsions, must, in the course of time, fall in. 
 
 If we embrace these views, important geological conse- 
 quences will follow ; since, if there be, upon the whole, more 
 subsidence than elevation, the average depth to which former 
 surfaces have sunk beneath their original level must exceed 
 the height which ancient marine strata have attained above 
 
 O 
 
 the sea. If, for example, marine strata, about the age 
 of our chalk and greensand, have been lifted up in Europe 
 to an extreme height of more than 11,000 feet, and a mean 
 elevation of some hundreds, we may conclude that certain 
 parts of the surface, which existed when those strata were 
 
240 EECAPITULATION OF CHAPS. XXXII. AND XXXIII. [CH. XXXIII. 
 
 deposited, have sunk to an extreme depth of more than 11,000 
 feet below their original level, and to a mean depth of more 
 than a few hundreds. 
 
 In regard to faults, also, we must infer, according to the 
 hypothesis now proposed, that a greater number have arisen 
 from the sinking down than from the elevation of rocks. 
 
 It seems, therefore, to be rendered probable, by the views 
 above explained, that the constant repair of the land, and the 
 subserviency of our planet to the support of terrestrial as 
 well as aquatic species, are secured by the elevating and 
 depressing power of causes acting in the interior of the 
 earth; which, although so often the source of death and 
 terror to the inhabitants of the globe visiting in succession 
 every zone, and filling the earth with monuments of ruin and 
 disorder are nevertheless the agents of a conservative prin- 
 ciple above all others essential to the stability of the system. 
 
 Recapitulation of Chapters XXXII. and XXXIII. I will 
 now recapitulate the principal conclusions arrived at in this 
 and in the preceding chapter. 
 
 1. The primary causes of the volcano and the earthquake 
 are to a great extent the same, and connected with the deve- 
 lopment of heat and chemical action at various depths in the 
 interior of the globe. 
 
 2. Volcanic heat has been supposed by many to be the result 
 of the high temperature which belonged to the whole planet 
 when it was in a state of igneous fusion, a temperature which 
 they suppose to have been always diminishing and still to 
 continue to diminish by radiation into space. 
 
 3. The spheroidal figure of the earth does not of necessity 
 imply a universal and simultaneous fluidity, in the beginning; 
 for whatever may have been the original shape of our planet, 
 the statical figure must have been assumed, if sufficient time 
 be allowed, by the gradual operation of the centrifugal force, 
 acting on yielding materials brought successively within its 
 action by aqueous and igneous causes. 
 
 4. The late Mr. Hopkins inferred that the precessional 
 motion of the earth could not be such as it now is, unless 
 the solid crust was from 800 to 1,000 miles thick; but the 
 precessional movement is consistent with the supposition of 
 
CH. XXXIII.] RECAPITULATION OF CHAPS. XXXII. AND XXXIII. 241 
 
 a much greater, and even the general solidity of the entire 
 globe, provided that lakes or oceans of melted matter, which 
 may be distributed through it, are so enclosed as to move 
 with the solid portion. 
 
 5. The heat in mines and Artesian wells increases as we 
 descend, but not in a uniform ratio, in different regions. If 
 the heat were continued downwards at the same rate, it would 
 imply such an elevation of temperature in the central nucleus 
 as must instantly fuse the crust. 
 
 6. The hypothesis of a central fluid and of a thin solid 
 shell resting or floating upon it, is inconsistent with the 
 absence of internal tides, such as would make the lava ebb 
 and flow in volcanic craters during eruptions. 
 
 7. The hypothesis of a change in the axis of rotation of a 
 supposed solid envelope, made to slide over an internal fluid 
 nucleus in consequence of the transfer of sediment from higher 
 to lower, or from lower to higher, latitudes, is untenable, 
 because the excess of matter displaced and carried in one 
 direction would be extremely slight, and the spheroidal figure 
 of the earth would render such freedom of motion impossible. 
 
 8. Assuming that there were good astronomical grounds 
 for inferring the original fluidity of the planet, such pristine 
 fluidity need not affect the question of volcanic heat, for the 
 volcanic action of successive periods belongs to a state of the 
 globe long posterior to its origin, and implies the melting of 
 different parts of the solid crust one after the other. 
 
 9. The quantity of lava, fluid at any one time in the earth's 
 crust, although it may be of importance in reference to super- 
 ficial changes, such as the formation of mountain chains, or 
 lines of volcanic vents, or regions of earthquakes, may still 
 be quite insignificant in relation to the size of an external 
 shell having a diameter of 50 miles. 
 
 10. The supposed greater energy of the volcanic forces in 
 the remoter periods is by no means borne out by geological 
 observations on the quantity of lava produced in those several 
 periods. 
 
 11. The old notion that the crystalline rocks, whether 
 stratified or unstratified, such as granite and gneiss, were 
 produced in the lower parts of the earth's crust at the expense 
 
 VOL. II. R 
 
242 RECAPITULATION OF CHAPS. XXXII. AND XXXIII. [Cn. XXXIII. 
 
 of a central nucleus slowly cooling from a state of fusion by 
 heat, has had to be given up, now that granite is found to be 
 of all ages, and now that we know the metamorphic rocks to 
 be altered sedimentary deposits implying the denudation of a 
 previously solidified crust. 
 
 12. (Chap. XXIII.) The powerful agency of steam or 
 aqueous vapour in volcanic eruptions leads us to compare its 
 power of propelling lava to the surface with that which it 
 exerts in driving up water in the pipe of an Icelandic Geyser. 
 Various gases, also rendered liquid by pressure at great 
 depths, may aid in causing volcanic outbursts, and in fissuring 
 and convulsing the rocks during earthquakes. 
 
 13. The number of active volcanos on sea-coasts and in 
 islands is probably connected with the agency of water in 
 volcanic operations. The latest chemical observations on 
 the products of recent eruptions, favour the doctrine that 
 large bodies of salt water gain access to the volcanic foci. 
 
 14. The flexibility of certain parts of the earth's crust, as 
 deduced from observations on earthquakes, may imply the 
 continuous existence of vast reservoirs of melted matter 
 beneath the surface, but such nevertheless as might hold a 
 very subordinate place in the earth's crust. 
 
 15. The existence of electrical currents in the earth's crust, 
 and the changes in direction which they may undergo after 
 great geological revolutions in the position of mountain chains 
 and of land and sea, the connection also of solar and terres- 
 trial magnetism, and of this last with electricity and chemical 
 action, may help us to conceive such a cycle of change as may 
 restore to the planet the heat supposed to be lost by radiation 
 into space. 
 
 16. The permanent elevation and subsidence of land now 
 observed, and which has been going on throughout past 
 geological ages, may be connected with the expansion and 
 contraction of parts of the solid ^rust, some of which have 
 been cooling from time to time, while others have been 
 gaining fresh accessions of heat. 
 
 17. In the preservation of the average proportion of land 
 and sea, the igneous agents exert a conservative power, re- 
 storing the unevenness of the surface, which the levelling 
 
CH. XXXIII.] RECAPITULATION OF CHAPS. XXXII. AND XXXIII. 243 
 
 power of water in motion would tend to destroy. If the 
 diameter of the planet remains always the same, the down- 
 ward movements of the crust must be somewhat in excess, to 
 counterbalance the effect of volcanos and mineral springs, 
 which are always bringing up materials from the interior of 
 the earth and pouring them out at the surface, so as to raise 
 its level. Subterranean movements, therefore, however de- 
 structive they may be during great earthquakes, are essential 
 to the well-being of the habitable surface, and even the very 
 existence of terrestrial species. 
 
 B 2 
 
244 
 
 BOOK III. 
 
 CHANGES OF THE ORGANIC WORLD NOW IN PROGRESS. 
 
 CHAPTEE XXXIY. 
 
 LAMARCK ON THE TRANSMUTATION OF SPECIES. 
 
 DIVISION OF THE SUBJECT EXAMINATION OF THE QUESTION, WHETHER 
 
 SPECIES HAYE A REAL EXISTENCE IN NATURE? IMPORTANCE OF THIS QUES- 
 TION IN GEOLOGY SKETCH OF LAMARCK'S ARGUMENTS IN FAVOUR OF THE 
 
 TRANSMUTATION OF SPECIES, AND HIS CONJECTURES RESPECTING THE ORIGIN 
 OF EXISTING ANIMALS AND PLANTS HIS THEORY OF THE TRANSFORMATION 
 OF THE ORANG-OUTANG INTO THE HUMAN SPECIES. 
 
 HITHERTO we have been occupied, from Chap. XV. to Chap. 
 XXXIII., with the consideration of the changes brought 
 about on the earth's surface, within the period of human ob- 
 servation, by inorganic agents ; such, for example, as rivers, 
 marine currents, volcanos, and earthquakes. But there is 
 another class of phenomena relating to the organic world, 
 which have an equal claim on our attention, if we desire to 
 obtain possession of all the preparatory knowledge respecting 
 the existing course of nature, which may be available in the 
 interpretation of geological monuments. It appeared from 
 our preliminary sketch of the progress of the science, that 
 the most lively interest was excited among its earlier culti- 
 vators, by the discovery of the remains of animals and plants 
 in the interior of mountains frequently remote from the sea. 
 Much controversy arose respecting the nature of these 
 remains, the causes which may have brought them into so 
 singular a position, and the want of a specific agreement 
 between them and known animals and plants. To qualify 
 ourselves to form just views on these curious questions, we 
 must first study the present condition of the animate creation 
 on the globe. 
 
CH. XXXIV.] MEANING OF THE TERM ' SPECIES.' 245 
 
 This branch of our enquiry naturally divides itself into two 
 parts : 
 
 First, we may consider the various meanings which have 
 been attached to the term ' species,' and the question which 
 has been raised whether each species has remained from its 
 origin the same, only varying within certain fixed and de- 
 fined limits, or whether a species may be indefinitely modified 
 in the course of a long series of generations. This will lead 
 us to examine into the dependence of each species of animal 
 and plant on certain fluctuating and temporary conditions in 
 the animate and inanimate world, and the consequent ex- 
 tinction of species one after the other, and the manner in 
 which the places left vacant may be supplied by new animals 
 and plants better fitted for the new conditions. 
 
 Secondly, we may consider the processes by which some 
 individuals of certain species may occasionally become fossil, 
 or be preserved in such a manner as to form part of the solid 
 framework of the earth's crust, so that they may serve in after 
 ages as monuments of the state of the living world at the 
 time when they became fossil. 
 
 Before we can advance a step in our enquiry, we must 
 endeavour to make up our minds as to the meaning which 
 we attach to the term ' species.' This is even more necessary 
 in geology than in the ordinary studies of the naturalist ; for 
 they who contend for the indefinite modifiability of species, 
 admit, nevertheless, that a botanist or zoologist may reason 
 as if the specific character were constant, because they confine 
 their observations to a brief period of time. Just as the 
 astronomer, in constructing his maps of the heavens, may 
 proceed century after century as if the apparent places of the 
 fixed stars remained absolutely the same, and as if no altera- 
 tion were brought about by the proper motion of the sun ; 
 so, it is said, in the organic world, the stability of a species 
 may be taken as absolute, if we do not extend our views 
 beyond the narrow period of human history ; but let a suffi- 
 cient number of centuries elapse, to allow of important 
 revolutions in climate, physical geography, and other cir- 
 cumstances, and the characters, say they, of the descendants 
 
246 LAMARCK'S THEORY OF THE [Cn. XXXIV. 
 
 of common parents may deviate indefinitely from their original 
 type. 
 
 Now, if these doctrines be tenable, we are at once presented 
 with a principle of incessant change in the organic world ; 
 and no degree of dissimilarity in the plants and animals 
 which may formerly have existed, and are found fossil, would 
 entitle us to conclude that they may not have been the proto- 
 types and progenitors of the species now living. Accordingly 
 MM. Lamarck and Geoffroy St. Hilaire declared their opinion 
 in the beginning of the present century that there had been 
 an uninterrupted succession in the animal kingdom, effected 
 by means of generation, from the earliest ages of the world 
 up to the present day, and that the ancient animals whose 
 remains have been preserved in the strata, however different, 
 may nevertheless have been the ancestors of those now in 
 being. In order to explain the facts and reasoning by which 
 this theory was originally supported, I cannot do better than 
 offer the reader a rapid sketch of the proofs which were 
 regarded by Lamarck as confirmatory of his views, shared 
 as they were to a great extent by his contemporary, Geoffroy 
 St. Hilaire.* 
 
 Lamarck's arguments in favour of the transmutation of 
 species. The name of ' species,' observes Lamarck, has been 
 usually applied to 'every collection of similar individuals 
 produced by other individuals like themselves. 'f This defini- 
 tion, he admits, is correct; because every living individual 
 
 * I have reprinted in this chapter, posed to the doctrine that the animals 
 word for word, my abstract of Lamarck's and plants now living were the lineal 
 doctrine of transmutation as drawn up descendants of distinct species only 
 by me in 1832 in the first edition of the known to us in a fossil state. There is, 
 ' Principles of Geology,' vol. ii. chap. i. therefore, no room for suspicion that my 
 I have thought it right to do this in jus- account of the Lamarckian hypothesis, 
 tice to Lamarck, in order to show how written by me thirty-five years ago, de- 
 nearly the opinions taught by him at rived any colouring from my own views 
 the commencement of this century re- tending to bring it more into harmony 
 sembled those now in vogue amongst a with the theory since promulgated by 
 large body of naturalists respecting the Darwin. The law of natural selection, 
 indefinite variability of species, and the by which th'e last-mentioned great 
 progressive development in past time of naturalist has thrown so much new light 
 the organic world. The reader must on the origin of species, will be ex- 
 bear in mind that when I made this plained in the next and succeeding 
 analysis of the ' Philosophie Zoolo- chapters, 
 gique,' in 1832, I was altogether op- f Phil. Zool. torn. i. p. 54. 1809. 
 
CH. XXXIV.] TRANSMUTATION OF SPECIES. 247 
 
 bears a very near resemblance to those from which it springs. 
 Bat this is not all which is usually implied by the term 
 ' species; ' for the majority of naturalists agree with Linnseus 
 in supposing that all the individuals propagated from one 
 stock have certain distinguishing characters in common, 
 which will never vary, and which have remained the same 
 since the creation of each species. Lamarck proposed, 
 therefore, to amplify the received definition in the following 
 manner. ' A species consists of a collection of individuals 
 resembling each other, and reproducing their like by genera- 
 tion, so long as the surrounding conditions do not alter to 
 such an extent as to cause their habits, characters, and forms 
 to vary.' 
 
 In order to show the grounds for this limitation of the 
 word ' species,' Lamarck entered upon the following line of 
 argument : The more we advance in the knowledge of the 
 different organised bodies which cover the surface of the 
 globe, the more our embarrassment increases to determine 
 what ought to be regarded as a species, and still more how 
 to limit and distinguish genera. In proportion as our col- 
 lections are enriched, we see almost every void filled up, 
 and all our lines of separation effaced! we are reduced to 
 arbitrary determinations, and are sometimes fain to seize 
 upon the slight differences of mere varieties, in order to 
 form characters for what we choose to call a species ; and 
 sometimes we are induced to pronounce individuals but 
 slightly differing and which others regard as true species, to 
 be varieties. 
 
 The greater the abundance of natural objects assembled 
 together, the more do we discover proofs that everything 
 passes by insensible shades into something else ; that even 
 the more remarkable differences are evanescent, and that 
 nature has, for the most part, left us nothing at our disposal 
 for establishing distinctions, save trifling, and, in some re- 
 spects, puerile peculiarities. 
 
 We find that ma.ny genera amongst animals and plants 
 are of such an extent, in consequence of the number of 
 species referred to them, that the study and determination 
 of these last has become almost impracticable. When the 
 
248 LAMARCK'S THEORY OF THE [Cn. XXXIV. 
 
 species are arranged in a series, and placed near to each 
 other, with due regard to their natural affinities, they each 
 differ in so minute a degree from those next adjoining, that 
 they almost melt into each other, and are in a manner con- 
 founded together. If we see isolated species, we may presume 
 the absence of some more closely connected, and which have 
 not yet been discovered. Already are there genera, and 
 even entire orders nay, whole classes which present an 
 approximation to the state of things here indicated. 
 
 If, when species have been thus placed in a regular series, 
 we select one, and then, making a leap over several inter- 
 mediate ones, we take a second, at some distance from the 
 first, these two will, on comparison, be seen to be very dis- 
 similar ; and it is in this manner that every naturalist begins 
 to study the objects which are at his own door. He then 
 finds it an easy task to establish generic and specific distinc- 
 tions ; and it is only when his experience is enlarged, and 
 when he has made himself master of the intermediate links, 
 that his difficulties and ambiguities begin. But while we 
 are thus compelled to resort to trifling and minute characters 
 in our attempt to separate species, we find a striking disparity 
 between individuals which we know to have descended from 
 a common stock ; and these newly acquired peculiarities are 
 regularly transmitted from one generation to another, consti- 
 tuting what are called races. 
 
 From a great number of facts, continues the author, we 
 learn that in proportion as the individuals of one of our 
 species change their situation, climate, and manner of living, 
 they change also, by little and little, the consistence and 
 proportions of their parts, their form, their faculties, and 
 even their organisation, in such a manner that everything in 
 them comes at last to participate in the mutations to which 
 they have been exposed. Even in the same climate, a great 
 difference of situation and exposure causes individuals to 
 vary ; but if these individuals continue to live and to be 
 reproduced under the same difference of circumstances, 
 distinctions are brought about in them which become in 
 some degree essential to their existence. In a word, at the 
 end of many successive generations, these individuals, which 
 
CH. XXXIV.] TRANSMUTATION OF SPECIES. 249 
 
 originally belonged to another species, are transformed into 
 a new and distinct species.* 
 
 Thus, for example, if the seeds of a grass, or any other 
 plant which grows naturally in a moist meadow, be acci- 
 dentally transported, first to the slope of some neighbouring 
 hill, where the soil, although at a greater elevation, is damp 
 enough to allow the plant to live ; and if, after having lived 
 there, and having been several times regenerated, it reaches 
 by degrees the drier and almost arid soil of a mountain 
 declivity, it will then, if it succeeds in growing, and per- 
 petuates itself for a series of generations, be so changed that 
 botanists who meet with it will regard it as a particular 
 species.* The unfavourable climate in this case, deficiency 
 of nourishment, exposure to the winds, and other causes, 
 give rise to a stunted and dwarfish race, with some organ 
 more developed than others, and having proportions often 
 quite peculiar. 
 
 What nature brings about in a great lapse of time, we 
 occasion suddenly by changing the circumstances in which 
 a species has been accustomed to live. All are aware that 
 vegetables taken from their birthplace, and cultivated in 
 gardens, undergo changes which render them no longer 
 recognisable as the same plants. Many which were naturally 
 hairy become smooth, or nearly so ; a great number of such 
 as were creepers and trailed along the ground, rear their 
 stalks and grow erect. Others lose their thorns or asperities; 
 others, again, from the ligneous condition which characterised 
 their stem in the hot climates, where they were indigenous, 
 pass to the herbaceous ; and, among them, some which were 
 perennials become mere annuals. So well do botanists know 
 the effects of such changes of circumstances, that they are 
 averse to describe species from garden specimens, unless 
 they are sure that they have been cultivated for a very short 
 period. 
 
 'Is not the cultivated wheat' (Triticum sativum), asks 
 Lamarck, ' a vegetable brought by man into the state in 
 which we now see it ? Let anyone tell me in what country 
 a similar plant grows wild, unless where it has escaped from 
 
 * Phil. Zool. torn. i. p. 63. 
 
250 CHANGES IN ANIMALS AND PLANTS [Cn. XXXIV. 
 
 cultivated fields ? Where do we find in nature our cabbages, 
 lettuces, and other culinary vegetables, in the state in which 
 they appear in our gardens ? Is it not the same in regard 
 to a great quantity of animals which domesticity has changed 
 or considerably modified ? ' * Our domestic fowls and 
 pigeons are unlike any wild birds. Our domestic ducks and 
 geese have lost the faculty of raising themselves into the 
 higher regions of the air, and crossing extensive countries in 
 their flight, like the wild ducks and wild geese from which 
 they were originally derived. A bird which we breed in a 
 cage cannot, when restored to liberty, fly like others of the 
 same species which have been always free. This small 
 alteration of circumstances, however, has only diminished 
 the power of flight, without modifying the form of any part 
 of the wings. But when individuals of the same race are 
 retained in captivity during a considerable length of time, 
 the form even of their parts is gradually made to differ, 
 especially if climate, nourishment, and other circumstances 
 be also altered. 
 
 The numerous races of dogs which we have produced by 
 domesticity are nowhere to be found in a wild state. In 
 nature we should seek in vain for mastiffs, harriers, spaniels, 
 greyhounds, and other races, between which the differences 
 are sometimes so great that they would be readily admitted 
 as specific between wild animals ; ' yet all these have sprung 
 originally from a single race, at first approaching very near 
 to a wolf, if, indeed, the wolf be not the true type which at 
 some period or other was domesticated by man.' 
 
 Although important changes in the nature of the places 
 which they inhabit modify the organisation of animals as 
 well as vegetables ; yet the former, says Lamarck, require 
 more time to complete a considerable degree of transmu- 
 tation; and, consequently, we are less sensible of such 
 occurrences. Next to a diversity of the medium in which 
 animals or plants may live, the circumstances which have 
 most influence in modifying their organs are differences in 
 exposure, climate, the nature of the soil, and other local 
 particulars. These circumstances are as varied as are the 
 
 * Phil. Zool. torn. i. p. 227. 
 
CH. XXXIV.] CAUSED BY DOMESTICATION. 251 
 
 characters of the species, and, like them, pass by insensible 
 shades into each other, there being every intermediate gra- 
 dation between the opposite extremes. But each locality 
 remains for a very long time the same, and is altered so 
 slowly that we can only become conscious of the reality of 
 the change by consulting geological monuments, by which 
 we learn that the order of things which now reigns in each 
 place has not always prevailed, and by inference anticipate 
 that it will not always continue the same.* 
 
 Every considerable alteration in the local circumstances in 
 which each race of animals exists causes a change in their 
 wants, and these new wants excite them to new actions and 
 habits. These actions require the more frequent employment 
 of some parts before but slightly exercised, and then greater 
 development follows as a consequence of their more frequent 
 use. Other organs no longer in use are impoverished and 
 diminished in size, nay, are sometimes entirely annihilated, 
 while in their place new parts are insensibly produced for the 
 discharge of new functions. f 
 
 I must here interrupt the author's argument, by observing, 
 that no positive fact is cited to exemplify the substitution of 
 some entirely new sense, faculty, or organ, in the room of 
 some other suppressed as useless. All the instances adduced 
 go only to prove that the dimensions and strength of mem- 
 bers and the perfection of certain attributes may, in a long- 
 succession of generations, be lessened and enfeebled by dis- 
 use; or, on the contrary, be matured and augmented by 
 active exertion ; just as we know that the power of scent is 
 feeble in the greyhound, while its swiftness of pace and its 
 acuteness of sight are remarkable that the harrier and 
 stag-hound, on the contrary, are comparatively slow in their 
 movements, but excel in the sense of smelling. 
 
 It was necessary to point out to the reader this important 
 chasin in the chain of evidence, because he might otherwise 
 imagine that I had merely omitted the illustrations for the 
 sake of brevity ; but the plain truth is, that there were no 
 examples to be found; and when Lamarck talked c of the 
 
 * Phil. Zoof. torn. i. p. 232. 
 t Ibid. p. 234. 
 
252 LAMAKCK'S THEOEY OF THE [Cu. XXXIV. 
 
 efforts of internal sentiment,' 'the influence of subtle fluids/ 
 and c acts of organisation,' as causes whereby animals and 
 plants acquire new organs, he substituted names for things ; 
 and resorted to fictions almost as ideal as the ' plastic 
 virtue ' of some geologists of the middle ages. 
 
 It is evident that, if some well-authenticated facts could 
 have been adduced to establish one complete step in the pro- 
 cess of transformation, such as the appearance, in indi- 
 viduals descending from a common stock, of a sense or organ 
 entirely new, and a complete disappearance of some other 
 enjoyed by their progenitors, time alone might then be sup- 
 posed sufficient to bring about any amount of metamor- 
 phosis. We must bear in mind, therefore, that a point so vital 
 to the theory of transmutation, was gratuitously assumed 
 by its advocate. 
 
 But to proceed with the system : it being taken for granted, 
 as an undoubted fact, that a change of external circum- 
 stances may cause one organ to become entirely obsolete and 
 a new one to be developed, such as never before belonged to 
 the species, the following proposition is announced, which, 
 however startling it may seem, is logically deduced from the 
 assumed premises. It is not the organs, or, in other words, 
 the nature and form of the parts of the body of an animal, 
 which have given rise to its habits and its particular facul- 
 ties ; but, on the contrary, its habits, its manner of living, 
 and those of its progenitors, have in the course of time 
 determined the form of its body, the number and condition 
 of its organs in short, the faculties which it enjoys. Thus 
 otters, beavers, waterfowl, turtles, and frogs, were not made 
 web-footed in order that they might swim ; but their wants 
 having attracted them to the water in search of prey, they 
 stretched out the toes of their feet to strike the water and 
 move rapidly along its surface. By the repeated stretching 
 of their toes, the skin which united them at the base ac- 
 quired a habit of extension, until, in the course of time, the 
 broad membranes which now connect their extremities were 
 formed. 
 
 In like manner, the antelope and the gazelle were not 
 endowed with light agile forms, in order that they might 
 
CH. XXXIV.] TKANSMUTATION OF SPECIES. 253 
 
 escape by flight from carnivorous animals ; but, having been 
 exposed to the danger of being devoured by lions, tigers, and 
 other beasts of prey, they were compelled to exert themselves 
 in running with great celerity ; a habit which, in the course 
 of many generations, gave rise to the peculiar slenderness of 
 their legs, and the agility and elegance of their forms. 
 
 The giraffe was not gifted with a long flexible neck be- 
 cause it was destined to live in the interior of Africa, where 
 the soil was arid and devoid of herbage ; but, being reduced 
 by the nature of that country to support itself on the foliage 
 of lofty trees, it contracted a habit of stretching itself up 
 to reach the high boughs, until its neck became so elongated 
 that it could raise its head to the height of 20 feet above the 
 ground. 
 
 Another line of argument was then entered upon, in 
 further corroboration of the instability of species. In order, 
 it was said, that individuals should perpetuate themselves 
 unaltered by generation, those belonging to one species 
 ought never to ally themselves to those of another; but 
 such sexual unions do take place, both among plants and 
 animals ; and though the offspring of such irregular connec- 
 tions are usually sterile, yet such is not always the case. 
 Hybrids have sometimes proved prolific, where the disparity 
 between the species was not too great ; and by this means 
 alone, says Lamarck, varieties may gradually be created by 
 near alliances, which would become races, and in the course 
 of time would constitute what we term species.* 
 
 After explaining his reasons for believing in the soundness 
 of the arguments and inferences above set forth, Lamarck 
 next proceeded to enquire what were the original types of 
 form, organisation, and instinct, from which the diversities 
 of character, as now exhibited by animals and plants, were 
 derived? We know, said he, that individuals which are 
 mere varieties of the same species would, if their pedigree 
 could be traced back far enough, terminate in a single stock ; 
 so, according to the same train of reasoning, the species of 
 a genus, and even the genera of a great family, must have 
 
 * Phil. Zool. p. 64. 
 
254 LAMARCK'S THEORY OF THE [Cn. XXXIV. 
 
 had a common point of departure. What, then, was the 
 single stem from which so many varieties of form have 
 ramified ? Were there many of these, or are we to refer the 
 origin of the whole animate creation, as the Egyptian 
 priests did that of the universe, to a single egg ? 
 
 In the absence of any positive data for framing a theory 
 on so obscure a subject, the following considerations were 
 deemed by Lamarck of importance to guide conjecture. 
 
 In the first place, if we examine the whole series of known 
 animals, from one extremity to the other, when they are 
 arranged in the order of their natural relations, we find that 
 we may pass progressively, or, at least, with very few inter- 
 ruptions, from beings of more simple to those of a more com- 
 pound structure ; and, in proportion as the complexity of 
 their organisation increases, the number and dignity of their 
 faculties increase also. Among plants, a similar approxima- 
 tion to a graduated scale of being is apparent. Secondly, it 
 appears, from geological observations, that plants and animals 
 of more simple organisation existed on the globe before the 
 appearance of those of more compound structure, and the 
 latter were successively formed at more modern periods ; each 
 new race being more fully developed than the most perfect of 
 the preceding era. 
 
 Of the truth of the last-mentioned geological theory, 
 Lamarck seems to have been fully persuaded ; and he also 
 shows that he was deeply impressed with a belief prevalent 
 amongst the older naturalists, that the primeval ocean in- 
 vested the whole planet long after it became the habitation 
 of living beings; and thus he was inclined to assert the 
 priority of the types of marine animals to those of the 
 terrestrial, so as to fancy, for example, that the testacea of 
 the ocean existed first, until some of them, by gradual evolu- 
 tion, were improved into those inhabiting the land. 
 
 These speculative views had already been, in a great degree, 
 anticipated by Demaillet in his Telliamed, and by several other 
 writers who preceded Lamarck ; so that the tables were com- 
 pletely turned on the philosophers of antiquity, with whom 
 it was a received maxim, that created things were always 
 most perfect when they came first from the hands of their 
 
CH. XXXIV.] TRANSMUTATION OF SPECIES. 255 
 
 Maker ; and that there was a tendency to progressive dete- 
 rioration in sublunary things when left to themselves 
 
 fatis 
 
 In pejus ruere, ac retro sublapsa referri. 
 
 So deeply was the faith of the ancient schools of philo- 
 sophy imbued with this doctrine, that, to check this uni- 
 versal proneness to degeneracy, nothing less than the re- 
 intervention of the Deity was thought adequate ; and 
 it was held, that thereby the order, excellence, and pristine 
 energy of the moral and physical world had been repeatedly 
 restored. 
 
 But when the possibility of the indefinite modification 
 of individuals descending from common parents was once 
 assumed, as also the geological inference respecting the 
 progressive development of organic life, it was natural that 
 the ancient dogma should be rejected, or rather reversed, 
 and that the most simple and imperfect forms and faculties 
 should be conceived to have been the originals whence all 
 others were developed. Accordingly, in conformity to these 
 views, inert matter was supposed to have been first endowed 
 with life ; until, in the course of ages, sensation was super- 
 added to mere vitality : sight, hearing, and the other senses 
 were afterwards acquired ; then instinct and the mental 
 faculties ; until, finally, by virtue of the tendency of things 
 to progressive improvement, the irrational was developed into 
 the rational. 
 
 The reader, however, will immediately perceive that when 
 all the higher orders of plants and animals were thus sup- 
 posed to be comparatively modern, and to have been derived 
 in a long series of generations from those of more simple 
 conformation, some further hypothesis became indispensable, 
 in order to explain why, after an indefinite lapse of ages, 
 there were still so many beings of the simplest structure. 
 Why have the majority of existing creatures remained 
 stationary throughout this long succession of epochs, while 
 others have made such prodigious advances ? Why are there 
 such multitudes of infusoria and polyps, or of confervse and 
 other cryptogamic plants ? Why, moreover, has the process 
 
256 LAMAKCK'S THEOKY OF THE [Cn. XXXIV. 
 
 of development acted with, such unequal and irregular force 
 on those classes of beings which have been greatly perfected, 
 so that there are wide chasms in the series ; gaps so enorm- 
 ous, that Lamarck fairly admits we can never expect to 
 fill them up by future discoveries ? 
 
 The following hypothesis was provided to meet these ob- 
 jections. Nature, we are told, is not an intelligence, nor 
 the Deity ; but a delegated power a mere instrument a 
 piece of mechanism acting by necessity an order of things 
 constituted by the Supreme Being, and subject to laws which 
 are the expressions of His will. This Nature is obliged to 
 proceed gradually in all her operations ; she cannot produce 
 animals and plants of all classes at once, but must always 
 begin by the formation of the most simple kinds, and out of 
 them elaborate the more compound, adding to them, succes- 
 sively, different systems of organs, and multiplying more and 
 more their number and energy. 
 
 This Nature is daily engaged in the formation of the ele- 
 mentary rudiments of animal and vegetable existence, which 
 correspond to what the ancients termed spontaneous genera- 
 tion. She is always beginning anew, day by day, the 
 work of creation, by forming monads, or f rough draughts ' 
 (ebauches), which are the only living things she gives birth 
 to directly* 
 
 There are distinct primary rudiments of plants and animals, 
 and probably of each of the great divisions of the animal 
 and vegetable kingdoms, f These are gradually developed 
 into the higher and more perfect classes by the slow but 
 unceasing energy of two influential principles : first, the 
 tendency to progressive advancement in organisation, accom- 
 panied by greater dignity in instinct, intelligence, &c. ; 
 secondly, the force of external circumstances, or of variations 
 in the physical condition of the earth, or the mutual re- 
 lations of plants and animals. For, as species spread them- 
 selves gradually over the globe, they are exposed from time 
 to time to variations in climate, and to changes in the 
 
 * Phil. Zool. pp. 65 and 204. 
 
 f Animaux sans Vert. torn. i. Introduction, p. 56 note. 
 
Cir. XXXIV.] TRANSMUTATION OF SPECIES. 257 
 
 quantity and quality of their food ; they meet with new 
 plants and animals which assist or retard their development, 
 by supplying them with nutriment, or destroying- their foes. 
 The nature, also, of each locality is in itself fluctuating ; so 
 that, even if the relation of other animals and plants were 
 invariable, the habits and organisation of species would be 
 modified by the influence of local revolutions. 
 
 Now, if the first of these principles, the tendency to pro- 
 gressive development, were left to exert itself with perfect 
 freedom, it would give rise, says Lamarck, in the course of 
 ages, to a graduated scale of being, where the most insensible 
 transition might be traced from the simplest to the most 
 compound structure, from the humblest to the most exalted 
 degree of intelligence. But, in consequence of the perpetual 
 interference of the external causes before mentioned, this 
 regular order is greatly interfered with, and an approxi- 
 mation only to such a state of things is exhibited by the 
 animate creation, the progress of some races being retarded 
 by unfavourable, and that of others accelerated by favourable, 
 combinations of circumstances. Hence, all kinds of anomalies 
 interrupt the continuity of the plan ; and chasms, into which 
 whole genera or families might be inserted, are seen to sepa- 
 rate the nearest existing portions of the series. 
 
 Lamarck's theory of the transformation of the orang-outang 
 into the human species. Such is the machinery of the La- 
 marckian 'system ; but the reader will hardly, perhaps, be 
 able to form a perfect conception of so complicated a piece 
 of mechanism, unless it is exhibited in action, so that we 
 may see in what manner it can work out, under the author's 
 guidance, all the extraordinary effects which we behold in the 
 present state of the animate creation. Without attempting 
 to follow the author through the entire process by which, 
 after a countless succession of generations, a small gelatinous 
 body is transformed into an oak or an ape, I shall pass on at 
 once to the last grand step in the progressive scheme, by 
 which the orang-outang, having been evolved out of a monad, 
 is made slowly to attain the attributes and dignity of man. 
 
 One of the races of quadrumanous animals which had 
 reached the highest state of perfection, lost, by constraint of 
 
 VOL. II. S 
 
258 CONVERSION OF THE ORANG-OUTANG- [Cn. XXXIV. 
 
 circumstances, the habit of climbing trees, and of hanging on 
 by grasping the boughs with their feet as with hands. The 
 individuals of this race being obliged, for a long series of 
 generations, to use their feet exclusively for walking, and 
 ceasing to employ their hands as feet, were transformed into 
 bimanous animals, and what before were thumbs became 
 mere toes, no separation being required when their feet were 
 used solely for walking. Having acquired a habit of holding 
 themselves upright, their legs and feet assumed, insensibly, 
 a conformation fitted to support them in an erect attitude, 
 till at last these animals could no longer go on all-fours 
 without much inconvenience. 
 
 The Angola orang (Simia troglodytes. Linn.) is the most 
 perfect of animals ; much more so than the Indian orang 
 (Simia Satyrus), which has been called the orang-outang, 
 although both are very inferior to man in corporeal powers 
 and intelligence. These animals frequently hold themselves 
 upright ; but their organisation has not yet been sufficiently 
 modified to sustain them habitually in this attitude, so that 
 the standing posture is very uneasy to them. When the 
 Indian orang is compelled to take flight from pressing 
 danger, he immediately falls down upon all-fours, showing 
 clearly that this was the original position of the animal. 
 Even in man, whose organisation, in the course of a long 
 series of generations, has advanced so much farther, the 
 upright posture is fatiguing, and can be supported only for 
 a limited time, and by aid of the contraction of many muscles. 
 If the vertebral column formed the axis of the human body, 
 and supported the head and all the other parts in equilibrium, 
 then might the upright position be a state of repose ; but, 
 as the human head does not articulate in the centre of 
 gravity, as the chest, belly, and other parts press almost 
 entirely forward with their whole weight, and as the verte- 
 bral column reposes upon an oblique base, a watchful activity 
 is required to prevent the body from falling.* Children who 
 have large heads and prominent bellies can hardly walk at 
 the end even of two years ; and their frequent tumbles indi- 
 
 * Phil. Zool. p. 353. 
 
CH. XXXIV.] INTO THE HUMAN SPECIES. 259 
 
 cate the natural tendency in man to resume the quadrupedal 
 state.* 
 
 Now, when so much progress had been made by the 
 quadrumanous animals before mentioned, that they could 
 hold themselves habitually in an erect attitude, and were 
 accustomed to a wide range of vision, and ceased to use 
 their jaws for fighting and tearing, or for clipping herbs for 
 food, their snout became gradually shorter, their incisor 
 teeth became vertical, and the facial angle grew more open. 
 
 Among other ideas which the natural tendency to perfection 
 engendered, the desire of ruling suggested itself, and this 
 race succeeded at length in getting the better of the other 
 animals, and made themselves masters of all those spots on 
 the surface of the globe which best suited them. They drove 
 out the animals which approached nearest them in organisa- 
 tion and intelligence, and which were in a condition to dis- 
 pute with them the good things of this world, forcing them 
 to take refuge in deserts, woods, and wildernesses, where 
 their multiplication was checked, and the progressive de- 
 velopment of their faculties retarded; while, in the mean- 
 time, the dominant race spread itself in every direction, and 
 lived in large companies, where new wants were successively 
 created, exciting them to industry, and gradually perfecting 
 their means and faculties. 
 
 In the supremacy and increased intelligence acquired by 
 the ruling race, we see an illustration of the natural tendency 
 of the organic world to grow more perfect ; and, in their 
 influence in repressing the advance of others, an example of 
 one of those disturbing causes before enumerated, that force 
 of external circumstances which causes such wide chasms in 
 the regular series of animated being. 
 
 When the individuals of the dominant race became very 
 numerous, their ideas greatly increased in number, and they 
 felt the necessity of communicating them to each other, and 
 of augmenting and varying the signs proper for the com- 
 munication of ideas. Meanwhile the inferior quadrumanous 
 animals, although most of them were gregarious, acquired 
 no new ideas, being persecuted and restless in the deserts, 
 
 * Phil. Zool. p. 354. 
 s 2 
 
260 OKIGIN OF SPEECH. [Cn. XXXIV. 
 
 and obliged to fly and conceal themselves, so that they 
 conceived no new wants. Such ideas as they already had 
 remained unaltered, and they could dispense with the com- 
 munication of the greater part of these. To make them- 
 selves, therefore, understood by their fellows, required merely 
 a few movements of the body or limbs whistling, and the 
 uttering of certain cries varied by the inflexions of the voice. 
 
 On the contrary, the individuals of the ascendant race, 
 animated with a desire of interchanging their ideas, which 
 became more and more numerous, were prompted to multiply 
 the means of communication, and were no longer satisfied 
 with mere pantomimic signs, nor even with all the possible 
 inflexions of the voice, but made continual efforts to acquire 
 the power of uttering articulate sounds, employing a few at 
 iirst, but afterwards varying and perfecting them according 
 to the increase of their wants. The habitual exercise of 
 their throat, tongue, and lips, insensibly modified the con- 
 formation of these organs, until they became fitted for the 
 faculty of speech.* 
 
 In effecting this mighty change, 'the exigencies of the 
 individuals were the sole agents ; they gave rise to efforts, 
 and the organs proper for articulating sounds were developed 
 by their habitual employment.' Hence, in this peculiar race, 
 the origin of the admirable faculty of speech ; hence also the 
 diversity of languages, since the distance of places where the 
 individuals composing the race established themselves soon 
 favoured the corruption of conventional signs. f 
 
 In conclusion, it may be proper to observe that the above 
 sketch of the Lamarckian theory is no exaggerated picture, 
 and those passages which have probably excited the greatest 
 surprise in the mind of the reader are literal translations from 
 the original. 
 
 * Lamarck's Phil. Zool. torn. i. p. 356. f Ibid - P- 3 ^7. 
 
261 
 
 CHAPTEE XXXV. 
 
 THEOEIES AS TO THE NATURE OF SPECIES, AND DARWIN 
 ON NATURAL SELECTION. 
 
 OBJECTIONS URGED AGAINST THE THEORY OF TRANSMUTATION AND LAMARCK' S 
 REPLIES MUMMIES OF ANIMALS AND SEEDS OF PLANTS FROM EGYPTIAN TOMBS 
 IDENTICAL IN CHARACTER WITH SPECIES NOW LIVING LINN.EUS' OPINION 
 
 THAT SPECIES HAVE BEEN CONSTANT SINCE THEIR CREATION BROCCHl's 
 
 HYPOTHESIS OF THE GRADUAL DIMINUTION OF VITAL POWER IN A SPECIES 
 
 WHETHER IF NEW SPECIES ARE CREATED FROM TIME TO TIME THEIR 
 
 FIRST APPEARANCE MUST HAVE BEEN WITNESSED BY THE NATURALIST 
 
 GEOFFROY ST. HILAIRE AND LAMARCK ON RUDIMENTARY ORGANS THE 
 
 QUESTION OF SPECIES AS TREATED OF IN THE ' VESTIGES OF CREATION ' MR. 
 
 ALFRED WALLACE ON THE LAW WHICH HAS REGULATED THE INTRODUCTION 
 OF NEW SPECIES MR. DARWIN ON NATURAL SELECTION AND MR. WALLACE 
 ON THE SAME DARWJN's ORIGIN OF SPECIES AND THE CHANGE OF OPINION 
 WHICH IT EFFECTED DR. HOOKER' S FLORA OF AUSTRALIA AND HIS VIEWS 
 AS TO THE ORIGIN OF SPECIES BY VARIATION. 
 
 OBJECTIONS URGED AGAINST THE THEORY OF TRANSMU- 
 TATION AND LAMARCK'S REPLIES. The theory of the 
 transmutation of species, considered in the last chapter, 
 was received with some degree of favour by many naturalists, 
 from their desire to dispense, as far as possible, with the 
 repeated intervention of a First Cause, as often as geological 
 monuments attest the successive appearance of new races 
 of animals and plants, and the extinction of those pre- 
 existing. But, independently of a predisposition to account, 
 if possible, for a series of changes in the organic world by 
 the regular action of secondary causes, we have seen that in 
 truth many perplexing difficulties present themselves to all 
 who attempt to establish the reality and constancy of the spe- 
 cific 'character. And if once there appears ground for 
 reasonable doubt, in regard to the constancy of species, the 
 amount of transformation which they are capable of under- 
 going might seem to resolve itself into a mere question of 
 
262 THEOEIES AS TO THE NATURE OF SPECIES. [Cn. XXXV- 
 
 the quantity of time assigned to the past and future duration 
 of animate existence. 
 
 The opponents of Lamarck objected to his arguments that 
 he could not adduce a single instanc'e of the gradual conver- 
 sion of any one species of animal or plant into another ; and 
 that in his appeal to the results obtained by the breeder and 
 horticulturist, he had failed to show such a change in the 
 structure and constitution of individuals descending from a 
 common stock as might fairly entitle the new race to rank as 
 a distinct species. It was conceded, for example, on all hands 
 that the modifications produced in the different races of dogs 
 exhibit the influence of man in the most striking point of view. 
 These animals had been transported into every climate, and 
 placed in every variety of circumstances : they had been made, 
 as M. Bureau de la Malle observed, the servant, the com- 
 panion, the guardian, and the intimate friend of man, and 
 the power of a superior genius had had a wonderful influence 
 not only on their forms, but on their manners and intelli- 
 gence. * Different races have undergone remarkable changes 
 in the quantity and colour of their clotiiing; the dogs of 
 Guinea are almost naked, while those of the arctic circle are 
 covered with a warm coat both of hair and wool, which enables 
 them to bear the most intense cold without inconvenience. 
 There are differences also of another kind no less remarkable, 
 as in size, the length of their muzzles, and the convexity of 
 their foreheads. ' The difference in stature,' said Cuvier, 
 6 in some canine races as compared to others is as 1 to 5 in 
 linear dimensions,' making a difference of a hundredfold in 
 volume.f 
 
 But, said the advocates of the immutability of species, if 
 we look for some essential changes, such as might serve as a 
 foundation for the theory of Lamarck, respecting the growth 
 of new organs and the gradual obliteration of others, we find 
 nothing of the kind. In all the varieties of the dog, as 
 Cuvier affirmed, the relation of the bones with each other 
 remains essentially the same ; the form of the teeth never 
 
 * Bureau de la Malle, An. des Sci. Nat, torn. xxi. p. 53, Sept. 1830. 
 f Cuvier, Discours Prelimin., p. 128. 
 
CH.XXXV.] EGYPTIAN MUMMIES. 263 
 
 changes in any perceptible degree, except that, in some 
 individuals, one additional false grinder occasionally appears, 
 sometimes on the one side, and sometimes on the other.* 
 The greatest departure from a common type and it con- 
 stitutes the maximum of variation as yet known in the animal 
 kingdom is exemplified in those races of dogs which have a 
 supernumerary toe on the hind foot with the corresponding 
 tarsal bones ; a variety analogous to one presented by six- 
 fingered families of the human race.f 
 
 It was moreover urged, and of all objections this was the 
 most serious, that however distinct were the various races of 
 the dog they could all breed freely together and produce 
 fertile offspring, as was also the case with various domesti- 
 cated birds, such as the common fowl, of which such marked 
 varieties had been obtained. In no instance had the mongrel 
 offspring been shown to be habitually sterile, like the common 
 mule or the offspring of the horse and ass, where the two 
 parents belong to two undoubtedly distinct species. 
 
 When the controversy had been brought to this point, and 
 the amount of possible variation of animals under domesti- 
 cation, and of plants under culture, was still under discus- 
 sion, the followers of Lamarck sometimes lamented that no 
 accurate descriptions, and figures of known species, had been 
 handed down from the e.arliest periods of history, such as 
 might have afforded data for comparing the condition of the 
 same species, at two periods considerably remote. To this, 
 however, the opponents of transmutation replied, that we are 
 in a great measure independent of such evidence, since, by a 
 singular accident, the priests of Egypt have bequeathed to 
 us, in their cemeteries, that information which the museums 
 and works of the Greek and Eoman philosophers have failed 
 to transmit. 
 
 It had fortunately happened that the men of science who 
 accompanied the French armies during their four years' occu- 
 pation of Egypt from 1797 to 1801, instead of employing 
 their whole time, as so many preceding investigators had 
 done, in exclusively collecting human mummies, had ex- 
 amined diligently, and sent home great numbers of embalmed 
 
 * Disc. Piel. p. 129, sixth edition. f Ibid. 
 
264 THEOKIES AS TO THE NATURE OF SPECIES. [Cn. XXXV. 
 
 bodies of consecrated animals, such as the bull, the dog, the 
 cat, the ape, the ichneumon, the crocodile, and the ibis. 
 
 They who have never raised their conceptions of the 
 import of Natural History beyond the admiration of beauti- 
 ful objects or the exertion of skill in detecting specific diffe- 
 rences, would wonder at the enthusiasm expressed in Paris 
 at the beginning of this century, amidst the din of arms and 
 the stirring excitement of political events, in regard to these 
 precious remains. In the official report, drawn up by the 
 Professors of the Museum at Paris, on the value of the objects 
 alluded to, the following passages might seem, extravagant, 
 unless we reflect how fully the reporters (Cuvier, Lacepede, 
 and Lamarck) appreciated the bearing of the facts thus 
 brought to light on the past history of the globe. 
 
 c It seems,' say they, ' as if the superstition of the ancient 
 Egyptians had been inspired by Nature, with a view of trans- 
 mitting to after ages a monument of her history. That 
 extraordinary and eccentric people, by embalming with so 
 much care the brutes which were the objects of their stupid 
 adoration, have left us, in their sacred grottos, cabinets of 
 zoology almost complete. The climate has conspired with 
 the art of embalming to preserve the bodies from corruption, 
 and we can now assure ourselves by our own eyes what was 
 the state of a great number of species three thousand years 
 ago. We can scarcely restrain the transports of our imagi- 
 nation, on beholding thus preserved, with their minutest 
 bones, with the smallest portions of their skin, and in every 
 particular most perfectly recognisable, many an animal, which 
 at Thebes or Memphis, 2,000 or 3,000 years ago, had its own 
 priests and altars.' * 
 
 Among the Egyptian mummies thus procured were not 
 only those of numerous wild quadrupeds, birds, and reptiles ; 
 but, what was perhaps oi still higher importance in helping 
 to decide the great question under discussion, there were the 
 mummies of domestic animals, among which those above 
 mentioned, the bull, the dog, and the cat, were frequent. 
 Now, such was the conformity, says Cuvier, of the whole of 
 these species and races to those now living, that there was no 
 
 * Ann. du Mus&nn d'Hist. Nat. torn. i. p. 234. 1802. 
 
CH.XXXV.] EGYPTIAN MUMMIES. 265 
 
 more difference between them than between the human mum- 
 mies and the embalmed bodies of men of the present day. Yet 
 some of these animals have since that period been trans- 
 ported by man to almost every variety of climate, and forced 
 to accommodate their habits to new circumstances as far as 
 their nature would permit. The cat, for example, has been 
 carried over the whole earth, and, within the last three 
 centuries, has been naturalised in every part of the New 
 World from the cold regions of Canada to the tropical 
 plains of Guiana ; yet it has scarcely undergone any percep- 
 tible mutation, and is still the same animal which was held 
 sacred by the Egyptians. Of the ox, undoubtedly, there are 
 many very distinct races : but the bull Apis, which was led 
 in solemn processions by the Egyptian priests, did not differ 
 from some of those now living. 
 
 Nor was the evidence derived from the Egyptian monu- 
 ments confined to the animal kingdom; the fruits, seeds, 
 and other portions of twenty different plants, were faithfully 
 preserved in the same manner ; and among these the com- 
 mon wheat was procured by Delille, from closed vessels in 
 the sepulchres of the kings, the grains of which retained not 
 only their form, but even their colour; so effectual had 
 proved the process of embalming with bitumen in a dry and 
 equable climate. No difference could be detected between 
 this wheat and that which now grows in the East and else- 
 where, and similar identifications were made in regard to 
 many other plants. 
 
 In answer to the argument drawn from this class of facts 
 Lamarck observed, that c the animals and plants referred to 
 had not experienced any modification in their specific cha- 
 racters, because the climate, soil, and other conditions of 
 life had not varied in the interval. But if,' he went on to 
 say, * the physical geography, temperature, and other natural 
 conditions of Egypt had altered as much as we know they 
 have done in many countries in the course of geological pe- 
 riods, the same animals and plants would have deviated from 
 their pristine types so widely as to rank as new and distinct 
 
 species.'"* 
 
 * Phil. Zool. pp. 70-71. 
 
26G THEORIES AS TO THE NATURE OF SPECIES. [On. XXXV. 
 
 This reply, when we consider its date (about the year 1809), 
 may well lay claim to our admiration, as it evinced Lamarck's 
 thorough conviction, that geological changes are brought 
 about so slowly that the lapse of thirty or forty centuries 
 is utterly insignificant in the history of a species. Nearly 
 all the men of science of his day, even the great majority of 
 geologists, entertained extremely narrow views in regard to 
 the duration of those periods of the past of which they 
 were studying the archives. They were generally inclined 
 to attribute all great changes of the earth's crust, and its 
 inhabitants, to brief and violent catastrophes, against which 
 Lamarck emphatically protested.* Yet neither he nor any 
 of his contemporaries could as yet form any conception of 
 the number and real magnitude of the revolutions in the ani- 
 mate world with which paleontology has since made us 
 familiar. In certain passages of his work he admitted that 
 possibly the Paleotherium, Anoplotherium, and some other 
 fossil genera of quadrupeds then recently described by Cuvier 
 as occurring in tertiary strata near Paris, may have disap- 
 peared, having, perhaps, been exterminated by the power of 
 man. But in regard to smaller animals, especially those of 
 the aquatic tribes, which could not have been the victims 
 of human intervention, he sometimes expressed a doubt 
 whether most of these may not still have their representatives 
 surviving in regions unexplored by the naturalist. Being 
 aware, however, that the specific and generic forms of ani- 
 mals and plants preserved in the rocks are more unlike 
 those now existing in proportion as they are more ancient, 
 Lamarck expressed his belief that in those cases where the 
 fossil animals could be identified with the living, the strata 
 containing them must be very modern, their descendants not 
 having had time to vary, except within extremely narrow 
 limits.f 
 
 It was by this constant reference to time as an essential 
 element even in the definition of a species, that the teaching 
 of Lamarck differed from that of Linnseus, Blumenbach, and 
 Cuvier. 
 
 * Phil. Zool. p. 80. 
 
 t Ibid. chap, iii., De 1'Espece, p. 79. 
 
CH. XXXV.] LINNAEUS ON SPECIES. 267 
 
 Linnceus on species. Linnseus in one of his treatises had 
 said that classes and orders are the inventions of science, 
 but species are the work of nature."* In another place he 
 went so far as to declare that genera, like species, are 
 primordial creations. f 
 
 Expressions may doubtless be found in some of his specu- 
 lative essays, implying that he thought that some species at 
 least were the daughters of time, ' temporis filicej J and we 
 shall see in Chap. XXXYII. that when a great number of 
 closely allied species existed in the same region, he strongly 
 suspected that they might be derived from other species pos- 
 sibly that they were hybrids, and had become so far perma- 
 nent as to require to be treated as distinct species. But his 
 deliberate opinion was contained in the following aphorism : 
 6 We reckon just so many species as there were different forms 
 created in the beginning.' Blumenbach declared that ' no 
 general rule can be laid down for determining the distinctness 
 of species, as there is no particular class of characters which 
 can serve as a criterion. In each case we must be guided by 
 analogy and probability. ' 
 
 In former editions of this work from 1832 to 1853, I did 
 not venture to differ from the opinion of Linnseus, that each 
 species had remained from its origin such as we now see it, 
 being variable, but only within certain fixed limits. The 
 mystery in which the origin of each species was involved 
 seemed to me no greater than that in which the beginning 
 of all vital phenomena on the earth is shrouded. But I 
 undertook to show that the gradual extinction of species one 
 after another was part of the constant and regular course of 
 nature, and must have been so throughout all geological 
 time, because the climate, and the position of land and sea, 
 and all the principal conditions of the organic and inorganic 
 world, are always, and have been always, undergoing change. 
 I pointed out how the struggle for existence among species, 
 and the increase and spread of some of them, must tend 
 
 * 'Classis et Ordo est sapientise, JTlora Suecica, ed. 2, 266, and Species 
 
 Species naturae opus.' Plantarum 770. 
 
 f ' Genus omne est naturale, in pri- ' Species tot numeramus quot di- 
 
 mordio tale creatum,' &c. (Phil. Bot. versse formse in principio sunt creatse.' 
 
 159. See also Ibid. 162.), (Phil. Bot. 157.) 
 
2G8 BROCCHI ON THE. DYING OUT OF SPECIES. [Cn. XXXV. 
 
 to the extermination of others ; and as these would dis- 
 appear gradually and singly from the scene, I suggested 
 that probably the coming in of new species would in like 
 manner be successive, and that there was no geological sanc- 
 tion for the favourite doctrine of some theorists, that large 
 assemblages of new forms had been ushered in at once to 
 compensate for the sudden removal of many others from the 
 scene. 
 
 Brocchi on the dying out of a species. An Italian geologist, 
 Brocchi, the author in 1814 of an able work on the fossil 
 shells of the Subapennine Hills, endeavoured to imagine 
 some regular and constant law by which species might 
 be made to disappear from the earth gradually and in suc- 
 cession. The death, he suggested, of a species might depend, 
 like that of individuals, on certain peculiarities of constitution 
 conferred upon them at their birth; and as the longevity 
 of the one depends on a certain force of vitality, which, 
 after a period, grows weaker and weaker, so the duration of 
 the other may be governed by the quantity of prolific power 
 bestowed upon the species which, after a season, may decline 
 in energy, so that the fecundity and multiplication of indi- 
 viduals may be gradually lessened from century to century, 
 ' until that fatal term arrives when the embryo, incapable 
 of extending and developing itself, abandons, almost at the 
 instant of its formation, the slender principle of life by 
 which it was scarcely animated, and so all dies with it.' * 
 In opposition to this doctrine, I contended that there is no 
 reason to suspect that the last individuals of a species of 
 which the numbers are diminishing is physiologically de- 
 teriorated, or is in the least degree impaired in its prolific 
 powers ; for there are known causes in the animate and in- 
 animate world which must in the course of ages annihilate 
 species, however vigorous their powers of reproduction 
 might remain. As the death of the last representatives of a 
 species would be abrupt, I conjectured that the birth of new 
 forms might be equally so, but as I had entire faith in the 
 doctrine that what is now going on in the natural world aifords 
 
 * Brocchi, Conch. Foss. Subap., tome i. 1814. 
 
CH.XXXV.] FIEST APPEARANCE OF NEW SPECIES. 269 
 
 a true indication of what has been and will be, I assumed that 
 the coming in of new species must be going on at about the 
 same rate as the dying out of old ones ; and I therefore felt 
 myself called upon to explain how the birth of new species 
 could be always in progress, and yet the botanist and zoolo- 
 gist remain wholly unconscious of the occurrence of events 
 so wonderful, and to them of such transcendent interest. 
 
 Difficulty of establishing the first appearance of a new 
 species. Assuming that species were specially created from 
 time to time to fill up the gaps to which the never-ceasing 
 changes of the animate and inanimate world must give rise, 
 I enquired what kind of evidence we had a right to expect 
 of the origin of new forms of animals and plants in the 
 course of the last twenty or thirty centuries. Ought we to 
 have been as conscious of the fact as we are of the lessening 
 of the mlmbers and the occasional extermination of par- 
 ticular species? It was obviously, I remarked, more easy 
 to prove that a species, once numerously represented in a 
 given district, had ceased to be, than that some other which 
 did not pre-exist had made its appearance assuming always 
 that single stocks only of each animal and plant are origin- 
 ally created, and that individuals of new species do not sud- 
 denly start up in many different places at once. The latter 
 hypothesis had already been considered by Linnaeus, and pro- 
 nounced by him to be unphilosophical because quite unneces- 
 sary, since, as he observed, every animal or plant, even those 
 which increase slowly, are capable in twenty or thirty gene- 
 rations of stocking a large part of the whole globe with their 
 descendants. 
 
 So imperfect has the science of Natural History remained 
 down to our own times, that, within the memory of persons 
 now living, the numbers of known animals and plants have 
 been doubled, or even quadrupled, in many classes. New 
 and often conspicuous species are annually discovered in 
 parts of the old continent, long inhabited by the most civi- 
 lised nations. Conscious, therefore, of the limited extent of 
 our information, we always infer, when such discoveries are 
 made, that the beings in question had previously eluded our 
 research ; or had at least existed elsewhere, and only migrated 
 
270 THEORIES AS TO THE NATURE OF SPECIES. [On. XXXV. 
 
 at a recent period into the territories where we now find 
 them. It is difficult to look forward to -the time when we 
 shall be entitled to make any other hypothesis in regard to 
 all the marine tribes, and to by far the greater number of 
 the terrestrial ; such as birds, and insects, and a large pro- 
 portion of plants, especially those of the cryptogamous class, 
 many of which possess such unlimited powers of diffusion as 
 to be almost cosmopolitan in their range. 
 
 It may perhaps be said that if new species were suddenly 
 called into being by special acts of creation, some forest tree 
 or new quadruped ought to have been seen, for the first time, 
 within the last ten or twenty centuries in the more populous 
 parts of such countries as England or France. In that 
 case, the naturalist might have been able to demonstrate 
 that no similar living form had before existed in the district. 
 
 Now, although this argument may seem plausible, its force 
 will be found to depend entirely on the rate of fluctuation 
 which we suppose to prevail in the animate world, and on 
 the proportion which such conspicuous subjects of the animal 
 and vegetable kingdoms bear to those which are less known 
 and escape our notice. There are perhaps more than a 
 million species of plants and animals, exclusive of the mi- 
 croscopic and infusory animalcules, now inhabiting the ter- 
 raqueous globe. The terrestrial plants may amount, said 
 De Candolle in 1820, to somewhere between 110,000 and 
 120,000.* Mr. Lindley, in a letter to the author in 1836, 
 expressed his opinion that it would be rash to speculate on 
 the existence of more than 80,000 phsenogamous, and 10,000 
 cryptogamous plants. ' If we take,' he says, ' 37,000 as the 
 number of published phsenogamous species, and then add, 
 for the undiscovered species of Asia and New Holland, 15,000, 
 10,000 in Africa, and 18,000 in America, we have 80,000 
 species ; and if 7,000 be the number of published cryptogamous 
 plants, and we allow 3,000 for the undiscovered species (mak- 
 ing 10,000), there would then be, on the whole, 90,000 species.' 
 
 Dr. J. Hooker, in 1859, when commenting on the varia- 
 bility of species and the indefinable nature of the limits by 
 
 * Geog. des Plantes. Diet, des Sci. Nat. 
 
CH. XXXV.] NUMBER OF LIVING SPECIES. 271 
 
 which they are separated one from the other, observed that 
 by some botanists the number of known species of flowering 
 plants is assumed to be under 80,000, and by others over 
 150,000.* 
 
 Linnseus imagined that there were four or five species of 
 insects in the world for each phsenogamous plant : but if we 
 may judge from the relative proportion of the two classes in 
 Great Britain, the number of insects must somewhat exceed 
 that estimate ; for the total number of British insects, ' ac- 
 cording to a census ' made in 1833, was about 1 2,500. f 
 
 The known species of mammifers, when Teniminck wrote, 
 exceeded 800, and according to Mr. Waterhouse more than 
 1,200 were ascertained to exist in 1850. J Baron Cuvier esti- 
 mated the fishes known in his time at 6,000. Mr. Gunther in- 
 forms me that specimens of more than that number of species 
 were already preserved in 1865 in the British Museum, and 
 that about 9,000 were known to the ichthyologist even before 
 the visit of Agassiz in 1866 to South America, where he is said 
 to have discovered at least 1,000 new species. We have still 
 to add the reptiles, and all the invertebrated animals, exclu- 
 sive of insects. 
 
 It remains, in a great degree, mere matter of conjecture 
 what proportion the aquatic tribes may bear to the denizens 
 of the land ; but the habitable surface beneath the waters 
 can hardly be estimated at less than double that of the con- 
 tinents and islands, even admitting that a very considerable 
 area is destitute of life, in consequence of great depth, cold, 
 darkness, and other circumstances. The ocean teems with 
 life the class of Polyps alone (Ccelenterata) are conjectured 
 by Lamarck to be as strong in individuals as insects. Every 
 tropical reef is described as covered with corals and sponges, 
 and swarming with crustaceans, sea-urchins, and mollusks ; 
 while almost every tide-washed rock in the world is car- 
 peted with Fuci, and supports some sea-anemones (Actimce), 
 Corallines (Bryozoa), and Testacea. There are also para- 
 sitic animals without number, three or four of which are 
 
 * Flora of Tasmania, vol. i. p. iii. \ Mr. G. Gray, in his genera of 
 
 1859. birds (1834) enumerated 8,000 species; 
 
 t See Catalogue of Erit. Insects, by Prince Charles Bonaparte, in 1854, 
 
 John Curtis, Esq. 8,300. 
 
272 THEOEIES AS TO THE NATURE OF SPECIES. [On. XXXV. 
 
 sometimes appropriated to one genus, as to the whale 
 (Balcena), for example. 
 
 In the exploring expeditions to the arctic and antarctic 
 regions, marine animals, such as crustaceans, mollusks, ser- 
 pulse, star-fish, and sponges, together with plants of the 
 simplest structure (Diatomacece) , have been found at depths 
 varying from 2,000 to 9,000 feet, sometimes inhabiting the 
 bottom, where the temperature of the water was below the 
 freezing-point. Even though we concede, therefore, that the 
 geographical range of marine species may be more extensive 
 in general than that of the terrestrial (the temperature of 
 the sea being more uniform, and the land impeding less the 
 migrations of the oceanic than the ocean those of the terres- 
 trial species), yet it seems probable that the aquatic tribes far 
 outnumber the inhabitants of the land. 
 
 Without insisting on this point, it may be safe to assume, 
 that, exclusive of microscopic beings, there are between one 
 and two millions of species now inhabiting the terraqueous 
 globe ; so that if only one of these were to become extinct 
 annually, and one new one were to be every year called into 
 being, much more than a million of years might be required 
 to bring about a complete revolution in organic life. 
 
 I have never ventured to hazard any precise hypothesis as to 
 the probable rate of change ; but none will deny that when the 
 annual birth and the annual death of one species on the 
 globe was proposed as a mere speculation, this at least was 
 to imagine no slight degree of instability in the animate 
 creation. If we divide the surface of the earth into twenty 
 regions of equal area, one of these might comprehend a space 
 of land and water about equal in dimensions to Europe, and 
 might contain a twentieth part of the million of species which 
 may be assumed to exist in the animal kingdom. In this 
 region one species only would, according to the rate of mor- 
 tality before assumed, perish in twenty years, or only five out 
 of fifty thousand in the course of a century. But as a consider- 
 able proportion of the whole would belong to the aquatic 
 classes, with which we have a very imperfect acquaintance, 
 we must exclude them from our consideration ; and if they 
 constitute half of the entire number, then one species only 
 
CH. XXXV.] KUDIMENTAKY OKGANS. 273 
 
 might be lost in forty years among the terrestrial tribes. 
 Now the Mammalia, whether terrestrial or aquatic, bear so 
 small a proportion to other classes of animals, forming less, 
 perhaps, than one thousandth part of the whole, that if the 
 longevity of species in the different orders were equal, a vast 
 period must elapse before it would come to the turn of this 
 conspicuous class to lose one of their number. If one species 
 only of the whole animal kingdom died out in forty years, no 
 more than one mammifer might disappear in 40,000 years 
 in a region of the dimensions of Europe. 
 
 It is easy, therefore, to see, that in a small portion of such 
 an area, in countries, for example, of the size of England and 
 France, periods of much greater duration must elapse before 
 it would be possible to authenticate the first appearance of 
 one of the larger plants and animals, assuming the annual 
 birth and death of one species to be the rate of vicissitude in 
 the animate creation throughout the world. It would follow 
 from the above considerations that if Lamarck was entitled 
 to plead insufficiency of time when challenged to bring 
 forward a single case of transmutation, the advocates of 
 special creation were equally entitled to say that if the intro- 
 duction of new species goes on as slowly as the extinction of 
 old ones, it could not be expected that they should have wit- 
 nessed the first starting into being of a new animal or plant. 
 
 Geoffroy St. Hilaire and Lamarck on rudimentary organs. 
 The great majority of the best naturalists and geologists who 
 succeeded Lamarck were content to believe with Humboldt 
 that the origin of species was one of those mysteries which 
 it was not given to natural science to penetrate. Omalius 
 d'Halloy, however, in his ' Elements of Geology/ which he 
 published in 1831, and in six subsequent editions, taught that 
 the species of animals now living were the descendants of 
 progenitors which have left their fossil remains in the later 
 Tertiary formations. I asked him in the year 1867, when 
 he was in his eighty-fourth year, by what facts and reasonings 
 he had been led to entertain this view, and he told me that 
 he owed his convictions on this head to the lectures of 
 Geoffroy St. Hilaire, to which he had listened in the early 
 part of this century at Paris. That great zoologist, he said, 
 
 VOL. II. T 
 
274 THEOEIES AS TO THE NATUEE OF SPECIES. [On. XXXV. 
 
 never lost an opportunity, when he spoke of the rudimentary 
 organs found in so many animals, of pointing out their 
 bearing on the theory of transmutation. According to him 
 they were clearly the relics of parts which had been service- 
 able in some remote ancestor and had been reduced in size by 
 disuse, and he rejected the idea as puerile that useless organs 
 had been created for the sake of uniformity of plan. 
 
 I may here remark that in my brief abstract of Lamarck's 
 theory drawn up by me originally in 1832, and which for 
 reasons explained in the last chapter (p. 246, note) I have 
 now reprinted without alteration or addition, I omitted, 
 when referring to what he had said on the impoverishment 
 and final disappearance of organs by disuse, to cite many 
 examples which he gives in the 'Philosophic Zoologique' in 
 illustration of this principle. Among other facts the abortive 
 teeth concealed in the jaws of some mammalia are mentioned, 
 such teeth not being required because their food is swallowed 
 without mastication. The discovery also by G. St. Hilaire 
 of teeth in the foetus of a whale is alluded to, and the small 
 size of the eyes in the mole which makes scarcely any use of 
 its organs of vision. Allusion is also made to the aquatic 
 reptile called Proteus anguinus, inhabiting the waters of dark 
 subterranean caverns, which retains only the vestiges or 
 rudiments of eyes.* 
 
 The question of species as treated in the ( Vestiges of Crea- 
 tion.' But, speaking generally, it may be said that all the 
 most influential teachers of geology, paleontology, zoology, 
 and botany continued till near the middle of this century 
 either to assume the independent creation and immutability 
 of species, or carefully to avoid expressing any opinion on this 
 important subject. In England the calm was first broken by 
 the appearance in 1844 of a work entitled ' The Vestiges of 
 Creation,' in which the anonymous author had gathered 
 together and presented to the public, with great clearness and 
 skill, the new facts brought to light in geology and the kin- 
 dred sciences since the time of Lamarck in favour of the 
 transmutation of species and their progressive development 
 
 * Phil. Zool. torn. i. p. 240, where other examples are also given. 
 
CH. XXXV.] THE -VESTIGES OF CREATION.' 275 
 
 in time. He availed himself of the generalisations of paleon- 
 tologists on the changes observable in the fossil fauna and 
 flora of successive epochs of the past, showing that the 
 structural affinity was greatest in those which stood nearest 
 each other in position when the strata were arranged in 
 chronological order, and that there had been a gradual 
 approximation of the animate world as it changed from 
 period to period to the state of things now represented by 
 the living creation. 
 
 The ernbryological investigations of Tiedemann and others 
 were referred to as being in harmony with the doctrine of 
 transmutation ; the various phases of development through 
 which a maminifer passes when in the foetal state representing 
 in succession the likeness of a fish, reptile and bird, and lastly 
 putting on the characters proper to the highest class of 
 vertebrata. It was also suggested that these metamorphoses 
 were comparable to the creative additions made in like 
 chronological order to the organic world of past ages as 
 revealed to us by the fossil remains preserved in the rocks. 
 The arguments which Lamarck and others had derived from 
 rudimentary organs in favour of their views were re-stated 
 and their validity emphatically insisted upon. The unity of 
 plan exhibited by the whole organic creation fossil and 
 recent, and the mutual affinities of all the different classes of 
 the animal and vegetable kingdoms, were declared to be in 
 harmony with the idea of new forms having proceeded 
 from older ones by generation, species having been gradually 
 modified by the influence of external conditions. 
 
 Lamarck had rendered his hypothesis very complete by 
 embracing without any essential change the notions of 
 Aristotle as to spontaneous generation. The simplest rudi- 
 ments or germs of life were assumed to be always coming into 
 being. This would account for the present abundance of 
 species of the lowest grades of animal and vegetable existence 
 in spite of the constant advance throughout past time of the 
 organic creation towards a more perfect state. In his eager- 
 ness to supply the evidence which was wanting to confirm 
 the reality of the working of this part of the plan of na- 
 ture, the author of the 'Vestiges' displayed an extraordinary 
 
276 WALLACE ON SPECIES, [Cn. XXXV. 
 
 want of philosophical caution. For he cited experiments 
 which were supposed to prove that the action of a voltaic pile 
 on a solution of potash could give origin to new species of 
 insects. The careless way in which these experiments had 
 been conducted contrasted in a striking manner with the 
 extreme caution displayed by those who had been endeavour- 
 ing to test the truth or falsehood of Harvey's dictum that 
 c every living thing comes from an egg.' The result of every 
 increase in the power of the microscope had been to refute 
 the theory of spontaneous generation, or at least to force the 
 abettors of the old doctrine to take refuge in the region of 
 the infinitely minute. Distrust of the soundness of the 
 author's judgment was also engendered by a suspicion that he 
 was not practically versed in the study of any one department 
 of natural knowledge. Every weak point, moreover, in this 
 treatise was exposed with unsparing severity by critics who 
 were impatient of the popularity it enjoyed, in spite of the 
 writer's adoption of Lamarck's doctrine that Man was not only 
 the last link of a long series of progressive developments, but 
 had been connected by descent with the inferior animals. 
 
 Wallace on species. The next important effort to determine 
 the manner in which new species may have originated was 
 made in 1855 by Mr. Alfred Wallace in the 'Annals of 
 Natural History, '* in an essay entitled c On the Law which 
 has regulated the Introduction of New Species.' The opinions 
 announced in this paper carried with them the authority of 
 one who was well versed in several departments of natural 
 history, especially ornithology and entomology. He had first 
 explored during fouu years, conjointly with Mr. H. W. Bates, 
 the valley of the river Amazons, and the neighbouring equa- 
 torial parts of South America, their expedition having been 
 expressly undertaken to collect facts 'towards solving the 
 problem of the origin of species. 'f Mr. Wallace had after- 
 wards spent many years in studying the zoology of the Malay 
 Archipelago, devoting his attention especially to the birds 
 and insects; and the result of his experience, aided by the 
 information obtained from geological writers, was summed 
 
 * Series 2, vol. xvi. 
 
 t Bates' Preface to his ' Naturalist on the River Amazons.' 
 
CH. XXXV.] AND DAKWIN ON NATURAL SELECTION. 277 
 
 up in the following proposition, ' that every species has come 
 into existence coincident both in space and time with a pre- 
 existing closely allied species.'* Mr. Darwin, f when re- 
 ferring subsequently to this paper in his Origin of Species,' 
 has stated that he knew from correspondence with Mr. Wal- 
 lace that the cause to which he attributed the coincidence 
 here alluded to was no other than ' generation with modifi- 
 cation,' or, in other words, the c closely allied anti-type ' was 
 the parent stock from which the new form had been derived 
 by variation. All the most telling arguments which Lamarck 
 had brought forward, and those drawn from various sources 
 which the 'Vestiges' had superadded, in favour of species 
 being the result of indefinite modification, instead of special 
 creation, were briefly and ably summed up by Mr. Wallace ; 
 but it was clear that the evidence which had most powerfully 
 influenced his mind, was that derived from his own experience 
 of the geographical distribution of species, and especially of 
 birds and insects. 
 
 In geography^ he remarked, a genus or species rarely occurs 
 in two very distant localities without being also found in the 
 intermediate space ; so in geology the life of a genus or 
 species is not interrupted, no species having come into 
 existence twice, or having been renewed after having once 
 died out. 
 
 For the manner in which the gradual extinction of species 
 had been brought about and was still in progress, Mr. 
 Wallace referred to my chapter on that subject in the ' Prin- 
 ciples of Geology,' confining his speculations to the manner 
 in which new forms were introduced from time to time to 
 replace those which were lost. 
 
 Darwin on Natural Selection and on the origin of species. 
 Meanwhile Mr. Charles Darwin, well known by his 6 Voyage in 
 the Beagle,' and various works on Geology, had been for many 
 years busily engaged in collecting materials for a great work 
 on the origin of species ; having made for that purpose a vast 
 series of original observations and experiments on domes- 
 ticated animals and cultivated plants, and having reflected 
 
 * Annals of Nat. Hist. ser. 2, vol. xvi. p. 186. 
 f 1st ed. p. 355 ; 4th ed. p. 424. 
 
278 THEORIES AS TO THE NATURE OF SPECIES, [Cn. XXXV. 
 
 profoundly on those problems in geology and biology which 
 were calculated to throw most light on that question. For 
 eighteen years these researches had all been pointing to the 
 same conclusion, namely, that the species now living had been 
 derived by variation and generation from those which had 
 pre-existed, and these again from others of still older date. 
 Several of his MS. volumes on this subject had been read by 
 Dr. Hooker as long ago as 1844, and how long the ever- 
 accumulating store of facts and reasonings might have re- 
 mained unknown to the general public, had no one else 
 attempted to work out the same problem, it is impossible to 
 say. But at length Mr. Darwin received 'a communica- 
 tion, dated February 1858, from Mr. Wallace, then re- 
 siding at Ternate in the Malay Archipelago, entitled c On 
 the Tendency of Varieties to depart indefinitely from the 
 Original Type.' 
 
 The Author requested Mr. Darwin to show this essay to 
 me should he think it sufficiently novel and interesting. 
 It was brought to me by Dr. Hooker, who remarked how 
 complete was the coincidence of Mr. Wallace's new views 
 and those contained in one of the chapters of Mr. Darwin's 
 unpublished work. Accordingly, he suggested that it would 
 be unfair to let Mr. Wallace's essay go to press unaccom- 
 panied by the older memoir on the same subject. Although, 
 therefore, Mr. Darwin was willing to waive his claim to 
 priority, the two papers were read on the same evening to 
 the Linnsean Society and published in their Proceedings for 
 1858. The title of the chapter extracted from Mr. Darwin's 
 MS. ran as follows : e On the Tendency of Species to form 
 Varieties, and on the Perpetuation of Species and Varieties 
 by Natural Means of Selection.' 
 
 Already in the previous year, September 1857, Mr. Darwin 
 had sent to Professor Asa Gray, the celebrated American 
 botanist, a brief sketch of his forthcoming treatise on what 
 he then termed c Natural Selection.' This letter, also printed 
 by the Linnsean Society together with the papers above alluded 
 to, contained an outline of the leading features of his theory 
 of selection as since explained, showing how new races were 
 formed by the breeder, and how analogous results might or 
 
CH. XXXV.] AND DARWIN ON NATURAL SELECTION. 279 
 
 must occur in nature under changed conditions in the ani- 
 mate and inanimate world. Beference was made in the 
 same letter to the law of human population first enunciated 
 by Malthus, or the tendency in man to increase in a geome- 
 trical ratio, while the means of subsistence cannot be made 
 to augment in the same ratio. We were reminded that in 
 some countries the human population has doubled in twenty- 
 five years, and would have multiplied faster if food could 
 have been supplied. In like manner every animal and plant 
 is capable of increasing so rapidly, that if it were un- 
 checked by other species, it would soon occupy the greater 
 part of the habitable globe ; but in the general struggle for 
 life few only of those which are born into the world can 
 obtain subsistence and arrive at maturity. In any given 
 species those alone survive which have some advantage over 
 others, and this is often determined by a slight peculiarity 
 capable in a severe competition of turning the scale in their 
 favour. Notwithstanding the resemblance to each other and 
 to their parents of all the individuals of the same family, no 
 two of them are exactly alike. The breeder chooses out 
 from among the varieties presented to him those best suited 
 to his purpose, and the divergence from the original stock 
 is more and more increased by breeding in each succes- 
 sive generation from individuals which possess the desired 
 characters in the most marked degree. In this manner Mr. 
 Darwin suggests that as the surrounding conditions in the 
 organic and inorganic world slowly alter in the course of 
 geological periods, new races which are more in harmony 
 with the altered state of things must be formed in a state of 
 nature, and must often supplant the parent type. 
 
 Although this law of natural selection constituted one only 
 of the grounds on which Mr. Darwin relied for establishing 
 his views as to the origin of species by variation, yet it 
 formed so original and prominent a part of his theory that 
 the fact of Mr. Wallace having independently thought out the 
 same principle and illustrated it by singularly analogous ex- 
 amples, is remarkable. It raises at the same time a strong 
 presumption in favour of the truth of the doctrine. Both 
 writers referred to the number of the feathered tribe which 
 
280 THEOEIES AS TO THE NATUKE OF SPECIES, [Cn. XXXV. 
 
 perish, annually. ' Yery few birds,' says Mr. Wallace, ' pro- 
 duce less than two young ones each year, while many have 
 six, eight, or ten ; and if we suppose that each pair produce 
 young only four times in their life, each would at this rate 
 increase in fifteen years to nearly ten millions, whereas we 
 have no reason to believe that the number of the birds of any 
 country increases at all in fifteen or even in 150 years. It is 
 evident, therefore, that each year an immense number of 
 birds must perish, as many in fact as are born ; and as on 
 the lowest calculation the progeny are each year twice as 
 numerous as their parents, it follows that whatever be the 
 average number of individuals existing in any given country, 
 twice that number must perish annually. 
 
 Large broods are superfluous : on the average all above 
 one become food for hawks and kites, wild cats and weazels, 
 or perish of cold and hunger as winter comes on.' * The most 
 remarkable instances of an immense bird population is that 
 of the passenger pigeon of the United States, which lays 
 only one or at most two eggs, and is said to rear generally but 
 one young one. Why is this bird so extraordinarily abundant, 
 while others producing two or three times as many young 
 are much less plentiful ? The explanation is not difficult. 
 The food most congenial to this species, and on which it 
 thrives best, is abundantly distributed over a very extensive 
 region, offering such differences of soil and climate, that in 
 one part or another of the area the supply never fails. The 
 bird is capable of very rapid and long-continued flight, so 
 that it can pass without fatigue over the whole of the district 
 it inhabits, and as soon as the supply of food begins to fail in 
 one place is able to discover a fresh feeding-ground. This 
 example strikingly shows us that the procuring a constant 
 supply of wholesome food is almost the sole condition re- 
 quisite for ensuring the rapid increase of a given species, 
 since neither the limited fecundity, nor the unrestrained 
 attacks of birds of prey and of man, are here sufficient to 
 check it.' f 
 
 When pointing out how every variation from the typical 
 
 * Journ. of Linnsean Soc., vol. iii. p. 55. 1858. 
 t Ibid. p. 55. 
 
CH. XXXV.] AND DAEWIN ON NATURAL SELECTION. 281 
 
 form of a species gives an advantage to some individuals 
 over others, Mr. Wallace shows that even a change of 
 colour, by rendering certain animals more or less distinguish- 
 able, affects their safety. He also observes that in a state of 
 nature, a race better fitted for changed conditions would never 
 revert to the form which it had displaced ; although in the 
 case of domesticated animals allowed to run wild or become 
 ' feral/ they must, to a certain extent, recover the character 
 which they had lost during their subjugation to man, for 
 reasons which will be explained in Chapter XXXYII. The 
 essay concluded with some judicious criticisms on Lamarck's 
 notion that animals may by their own efforts promote the 
 development of some of their organs, or even acquire new ones. 
 ' Changes,' says Mr. Wallace, ' have been brought about, not 
 by the volition of the creatures themselves, but by the sur- 
 vival of varieties which had the greatest facilities of obtaining 
 food. The giraffe did not acquire its long neck by desiring 
 to reach the foliage of lofty trees and by constantly stretching 
 out its neck for that purpose, but varieties which occurred 
 with a longer neck than usual had an advantage over their 
 shorter-necked companions, and, on the first scarcity of food, 
 were enabled to survive them.' * 
 
 After the publication of the detached chapter of his book 
 in the Limisean Proceedings, Mr. Darwin was persuaded by 
 his friends that he ought no longer to withhold from the 
 world the result of his investigations on the nature and 
 origin of species, and his theory of Natural Selection. Great 
 was the sensation produced in the scientific world by the 
 appearance of the abridged and condensed statement of his 
 views comprised in his work entitled ' On the Origin of 
 Species by means of Natural Selection, or the Preservation 
 of Favoured Eaces in the Struggle for Life.' From the hour 
 of its appearance it gave, as Professor Huxley truly said, ' a 
 new direction to biological speculation,' for even where it 
 failed to make proselytes, it gave a shock to old and time- 
 honoured opinions from which they have never since re- 
 covered. It effected this not merely by the manner in which 
 
 * Journ. of Linnsean Soc. p. 61. 
 
282 THEOEIES AS TO THE NATUKE OF SPECIES. [Cn. XXXV. 
 
 it explained how new races and species might be formed by 
 Natural Selection, but also by showing that, if we assume 
 this principle, much light is thrown on many very distinct 
 and otherwise unconnected classes of phenomena, both in the 
 present condition and past history of the organic world. 
 
 Hooker on variation and selection and the formation of species 
 in the vegetable world. The abandonment of the old received 
 doctrine of the c immutability of species ' was accelerated in 
 England by the appearance, in the same year (1859), of Dr. 
 Hooker's essay on the Flora of Australia. In several of his 
 previous writings this eminent botanist had said all that could 
 be said in support of the ' constancy of the specific character in 
 the vegetable world.' He had been freely discussing for fifteen 
 years with Mr. Darwin, all the facts and arguments which 
 they could bring to bear on this question, but he stated in 
 his Introduction, that until the views of his friend and those 
 of Mr. Wallace in favour of Natural Selection had been made 
 known, he scarcely felt himself at liberty frankly to declare 
 how far, as a botanist, he was prepared to go in the same 
 direction. He had been occupied for more than twenty 
 years in the study of plants of various parts of the world, 
 arctic, temperate, and tropical, insular and continental. He 
 had personally explored the floras of several of these regions, 
 had described and classified thousands of species, and was 
 well known to unite caution with boldness in his philoso- 
 phical speculations. From his new essay the general public 
 learnt, not without surprise, how little the most experienced 
 botanists are agreed amongst themselves as to the limits of 
 species, and to what an extent these limits are a mere matter 
 of opinion, even amongst those who believe that species have 
 remained unchanged since their creation, and will remain 
 immutable as long as they continue on the globe. 
 
 Dr. Hooker showed that in proportion as we study the 
 same plant under varied conditions and in distant regions, it 
 becomes more and more difficult to define its precise specific 
 characters ; also that in the flora of every country there are 
 some groups of species which are apparently unvarying, 
 others which on the contrary run so much one into another 
 that the whole group may be regarded as a continuous series 
 
CH. XXXV.] HOOKER ON SPECIES IN THE VEGETABLE WORLD. 283 
 
 of varieties between the terms of which no hiatus exists such 
 as might allow of the intercalation of any intermediate 
 variety. The genera Rubus, Rosa, Salix, and Saxifraga 
 afford conspicuous examples of these unstable forms ; Ve- 
 ronica, Campanula, and Lobelia of comparatively stable ones. 
 At the same time he points out in accordance with Mr. 
 Darwin's theory how the extinction of a certain number of 
 the intermediate races by destroying the transitional links, 
 would facilitate the classification of the remaining species, 
 and hints that we may be indebted to such extinction in 
 past times for whatever facility we now enjoy of resolving 
 plants into distinct species, genera, and orders. f The mutual 
 relations/ he observes, 6 of the plants of each great botanical 
 province, and in fact, of the world generally, is just such as 
 would have resulted if variation had gone on operating 
 throughout indefinite periods, in the same manner as we see 
 it act in a limited number of centuries, so as gradually to 
 give rise in the course of time to the most widely divergent 
 forms.' 
 
 When we reflect that this statement was made after a 
 study of the characters and geographical distribution of tens 
 of thousands of species, we feel disposed at once to declare 
 that a theory which is in harmony with so many facts must 
 be true ; but if so, we have to enquire how it happens that so 
 many naturalists, of undoubted ability and knowledge, have 
 always held and still believe that species have been constant 
 from the beginning. In reference to this question, Dr. 
 Hooker admits that species are realities and may be treated 
 as if they were permanent and immutable ; for the forms and 
 characters, at least of the great majority of them, may be 
 faithfully transmitted through thousands of generations, and 
 may have remained constant within the range of our experi- 
 ence. c But our experience,' he remarks, i is so limited that 
 it will not account for a single fact in the present geo- 
 graphical distribution, or origin of any one species of plant, 
 nor for the amount of variation it has undergone, nor will 
 it indicate the time when it first appeared nor the form it 
 had when created.' * 
 
 * Hooker, Introductory Essay, Flora of Tasmania. 
 
284 
 
 CHAPTEE XXXYI. 
 
 VARIATION OP PLANTS AND ANIMALS UNDER DOMESTICATION 
 VIEWED AS BEARING ON THE ORIGIN OF SPECIES. 
 
 DOMESTIC RACES, HOWEVER DIVERGENT, BREED FREELY TOGETHER REMOTE 
 ANTIQUITY OP SOME ARTIFICIALLY FORMED RACES SELECTION, BOTH UNCON- 
 SCIOUS AND METHODICAL, VERY INFLUENTIAL IN FORMING NEW RACES 
 
 THE CHARACTERS OF SOME RACES OF THE DOMESTICATED PIGEON OF GENERIC 
 VALUE REVIVAL OF LONG-LOST CHARACTERS IN THE OFFSPRING OF CROSS- 
 BREEDS MULTIPLE ORIGIN OF THE DOG INHERITED INSTINCTS VARIATION 
 
 OF THE GOLD FISH AND SILKWORM MAN CAUSES PARTICULAR PARTS OF AN 
 
 ANIMAL OR PLANT TO VARY WHILE OTHER PARTS CONTINUE UNALTERED 
 
 MAIZE CABBAGE ARE THERE ANY LIMITS TO THE VARIABILITY OF A 
 
 SPECIES ? OBEDIENCE TO MAN UNDER DOMESTICATION OFTEN MERELY A 
 
 NEW ADAPTATION OF A NATURAL INSTINCT 'FERAL* VARIETIES DO NOT 
 REVERT TO THE EXACT LIKENESS OF THE ORIGINAL WILD STOCK HOW FAR 
 DO DOMESTIC RACES DIFFER FROM WILD SPECIES IN THEIR CAPACITY TO INTER- 
 BREED ? HYBRIDISATION OF ANIMALS AND PLANTS HERMAPHRODITE PLANTS 
 
 NOT USUALLY SELF-FERTILISED WHETHER THE DISTINCTNESS OF SPECIES 
 
 CAN BE TESTED BY HYBRIDITY TENDENCY OF DIFFERENT RACES OF DOMESTIC 
 
 CATTLE AND SHEEP TO HERD APART PALLAS ON DOMESTICITY ELIMINATING 
 STERILITY CORRELATION OF GROWTH. 
 
 DOMESTIC RACES, HOWEVER DIVERGENT, BREED FREELY 
 TOGETHER. We have seen that the indefinite modifiability of 
 species in the course of thousands of generations, and under 
 gradually altered conditions in the organic and inorganic 
 world, is a question which has been seriously entertained 
 by naturalists ever since the beginning of the present 
 century. The changes brought about by the breeder and 
 horticulturist, and the new races to which they have given 
 origin, have always been appealed to in support of this theory 
 of unlimited variability. It may be said that man, in every 
 stage of his social progress, has been engaged in conducting, 
 with much patience and at enormous cost, a grand series of 
 experiments to ascertain how far it is possible to make the 
 descendants of common parents, both in the animal and 
 vegetable kingdoms, deviate from their original type. In pur- 
 
CH. XXXVI.] ANTIQUITY OF ARTIFICIALLY FORMED RACES. 285 
 
 suing this course he has by no means confined his attention 
 to plants and animals which minister to his wants, but he has 
 sometimes gone on for thousands of years simply for his amuse- 
 ment, trying how far he could alter certain species the pigeon, 
 for example, or some flowering plants such as the rose. 
 
 The opponents of the doctrine of transmutation have 
 always objected to arguments founded on the results of such 
 experiments, that, in spite of the skill and perseverance of the 
 breeder, agriculturist, and florist, man has never succeeded in 
 giving origin to one new species. For however far some of 
 the new races may have diverged from the parent stock 
 or from each other, they have always continued to breed 
 freely together and produce fertile offspring, whereas the 
 hybrids which result from the union of two distinct species 
 in nature are always sterile. 
 
 Before we can decide on the weight which we must 
 attach to such an objection, we must consider not only the 
 nature and extent of the changes which have been effected in 
 species under domestication and culture, but also the facility 
 of obtaining hybrid plants and animals of wild species, and 
 the different degrees of sterility of the hybrids when obtained. 
 The whole subject of the variation of domesticated animals 
 and cultivated plants has been lately treated of, with so much 
 ability and in such detail, by Mr. Darwin in a new work 
 just published,* that I cannot do better than refer the 
 reader to his clear statements of the facts and of their bearing 
 on his theory of the c Origin of Species.' In this chapter, 
 besides repeating much that I advanced in former editions, 
 I shall allude briefly to some of the valuable observations 
 and experiments which he has made, and the theoretical 
 conclusions to which they point. 
 
 Hemote antiquity of some artificially formed races. The ex- 
 plorations so actively carried on within the last fifteen 
 years in the Swiss lake-dwellings, and an examination 
 of the remains of animals and plants there preserved, have 
 shown that domesticated races of the dog, the ox, and the 
 sheep, and cultivated varieties of several cereals and of many 
 fruits, had been formed in Central Europe in the Neolithic 
 
 * The Variation of Plants and Animals under Domestication : 1867. 
 
286 VARIATION OF PLANTS AND ANIMALS. [Cn. XXXVI. 
 
 age, or before the use of metals was yet known. The 
 antiquity which we are thus called upon to assign to the 
 culture of certain plants need not surprise us, if Mr. Darwin 
 is correct in his opinion, that man in a barbarous state is 
 naturally led to discover the useful properties of all wild 
 plants by the frequently recurring famines to which all savage 
 tribes are exposed; for when in danger of starving he is 
 compelled to try as food every kind of fruit, leaf, and root. 
 By this means the nutritious, stimulating, and medical 
 qualities of the most unpromising species are brought to light. 
 
 It might have been thought that the seeds of wild grasses 
 were too minute to afford much temptation for men in a rude 
 state of society to cultivate them for food ; but it seems that 
 both Barth and Livingstone* observed the natives in different 
 parts of Africa collecting the seeds of wild grasses, and 
 eating them ; from which practice it would be an easy step to 
 pass to the sowing of some of them near their usual haunts, 
 and eventually to the selection for seed of those varieties which 
 yielded the largest crops. The great number of cultivated 
 grasses or cereals, and the difficulties which botanists en- 
 counter when they endeavour to trace them to their original 
 stocks, or to the wild species from which they have sprung, 
 becomes more intelligible if we suppose that they have 
 undergone considerable modifications under culture in pre- 
 historic times. 
 
 It has often been remarked that we do not owe a single 
 useful plant to Australia or the Cape of Good Hope, or to 
 New Zealand, or to America south of the Plata. On this 
 subject Mr. Darwin observes, that we must by no means 
 infer that in these countries no native plants have proved 
 useful to savage man. Dr. Hooker, indeed, enumerates no 
 less than 107 native speciesf which are used even by the 
 Australians. But the small advantage which civilised man 
 has hitherto derived from the regions above alluded to simply 
 demonstrates that wild plants cannot compete with those 
 which have been improved by cultivation for a long series of 
 generations. 
 
 * Cited by Darwin ' On Variation of t Flora of Australia, Introduction, 
 Animals,' &c., 1867, p. 308. p. ex. 
 
CH. XXXVI.] PLANTS AND ANIMALS OF THE LAKE-DWELLEKS. 287 
 
 A skilful botanist who should see for the first time our 
 finest varieties of apples, peaches, pears, and plums, would be 
 unable to guess from what species of wild trees they had 
 been derived. 
 
 De Candolle mentions no less than thirty-three useful 
 plants which we owe to Mexico, Peru, and Chili, among which 
 the maize and potato are conspicuous ; and Tschudi describes 
 two forms of maize no longer known in Peru, which were 
 taken from the tombs of the Incas,* and which had become 
 extinct before the arrival of the Spaniards in South America. 
 But strange to say, 110 botanist has yet been able to trace the 
 maize, which had evidently been cultivated from a very re- 
 mote period, to any wild aboriginal parent stock. 
 
 The slowness with which improved varieties of native plants 
 have been brought into existence may be inferred from the 
 researches of Oswald Heer with respect to the fruits belonging 
 to the Swiss lake-dwellers of the later Stone period. They 
 had collected wild crabs, sloes, bullaces, elderberries, hips of 
 roses and beech-mast differing but slightly from those which we 
 know in a wild state. They had also five kinds of wheat and 
 three of barley, mostly inferior in size to ours. Among them 
 was the wheat commonly called Egyptian ; a fact leading to 
 the inference that the lake-dwellers had either come originally 
 from the south or had intercourse with some southern people. 
 So in regard to the domesticated animals of the same lake- 
 dwellers, they do not agree exactly with any of our breeds. 
 Thus for example, they had two kinds of cattle which are 
 considered as modifications of two species or races which then 
 existed in a wild state namely, Bosprimigenius and Bos longi- 
 frons ; but, although they were modifications of these original 
 types, they cannot be identified with any existing European 
 breeds. Their dog also differed from ours, or from that of the 
 later Bronze period, and according to Riitimeyer was of a 
 middle size, and equally remote from the wolf and the jackal. 
 They had also a small breed of sheep with thin and tall legs 
 and with horns like those of a goat, which was not exactly 
 similar to any one of the races now known. 
 
 * Cited by Darwin ' On Variation,' &c., p. 320. 
 
288 VAEIATION OF PLANTS AND ANIMALS. [On. XXXVI, 
 
 Selection., both unconscious and methodical, very influential 
 in forming new races. When the art of the breeder has been 
 greatly perfected, he is able to bring about very important 
 changes in a short time. He has no power either of causing 
 or preventing the numerous varieties which nature presents 
 to him among individuals born of the same parents. But 
 he can choose those which best suit his purpose, and breed 
 from them, while he destroys those varieties which are less 
 valuable. In the next generation he again picks out those 
 individuals which possess the desired qualities in a somewhat 
 more marked degree; and so goes on accumulating these 
 differences till he produces a breed which answers to some 
 preconceived idea formed by him. He can discriminate 
 trifling variations both in animals and plants which an unedu- 
 cated eye cannot appreciate. The variations which are thus 
 intensified become fixed by inheritance, and permanent races 
 are formed a process technically called selection. But there 
 is another kind of selection, termed ' unconscious ' by Mr. 
 Darwin, which perhaps acts more powerfully in the long run, 
 both in a rude and civilised state of society. The savage, 
 when pressed by hunger, is often driven to feed on his dogs ; 
 in which case, if he is able to retain any of them, he preserves 
 such as are most useful to him in the chase. So in a very 
 early state of agriculture, the seeds and fruits of those varie- 
 ties which offer some advantage over others, by the abundance 
 of their produce or the quality or flavour of the nutriment 
 they afford, will be sown by preference, whereas the seeds of 
 less prized varieties will be consumed. For man is always 
 called upon to decide which individuals shall be spared as a 
 stock from whiclx to breed, so many more being always born 
 into the world than there is room or food for. Mr. Darwin 
 supposes that, even in the most advanced state of society, 
 the influence of unconscious selection acts more powerfully 
 than methodical selection. 
 
 Our present bull-dogs, he observes, are different from those 
 formerly used for baiting bulls, being of smaller size and 
 altered in shape, now that the old sport has been given up. 
 Our fox-hounds differ from the old English hound, and our 
 greyhounds have become lighter. Our enormous dray-horses 
 
CH. XXXVI.] GREAT DIVERGENCE OF TYPE IN THE PIGEON. 289 
 
 have been produced from some ancient bulky race through 
 the unconscious selection, carried on during many generations 
 in Flanders and England, of the most powerful and heaviest 
 horses, without the least intention or expectation of creating 
 our present elephant-like breed.* After the introduction 
 into England of some Arab horses, the methodical selection 
 of the swiftest individuals gradually produced the English 
 race-horse. But even this change has been partly effected 
 unconsciously, by the general wish to breed as fine horses as 
 possible, without any intention to give to them their present 
 character. 
 
 The characters of some races of the domesticated pigeon of 
 generic value. Domestic pigeons afford a most striking illus- 
 tration of the great divergence from the original type, the 
 rock pigeon (Columba Livia), which man has brought about in 
 the course of time. These birds have been domesticated for 
 thousands of years in Egypt and India, and they afford 
 remarkable facilities for the production of distinct breeds, as 
 the male and female birds can be easily mated for life, and 
 the different varieties kept together in the same aviary. 
 More than 150 distinct races have received names, all breed- 
 ing true ; and at least a score of these, says Mr. Darwin, 
 might be named, which, if shown to an ornithologist, and he 
 was told they were wild birds, would be ranked by him as 
 well-defined species, while some of them, such as the carrier, 
 short-faced tumbler, pouter and fan-tail, would not even be 
 placed in the same genus. From, historical details which 
 have come down to us of the principal races of the pigeon 
 as they were known in India before the year 1600, it appears 
 that these races, although they might have been classed in 
 the same groups as our present breeds, had not diverged in 
 so great a degree from their aboriginal common parent, the 
 wild rock pigeon. 
 
 Pigeon-fanciers in forming new varieties have confined their 
 attention to external characters such as the length of the 
 beak, the number or length of the tail feathers, the colour of 
 the plumage, and the general shape of the body, yet they 
 
 * Darwin 'On Variation,' chap. xx. p. 212. 
 VOL. II. U 
 
290 VARIATION OF PLANTS AND ANIMALS. [Cn. XXXVI. 
 
 have sometimes unintentionally produced modifications in 
 the internal bony framework of the species. Thus while 
 they have given a longer body to the pouter, they have unin- 
 tentionally augmented the number of its sacral and caudal 
 vertebra?, and the breadth of the ribs as well as the size of 
 the breast-bone. In the fan-tail they have increased con- 
 siderably the length and number of the caudal vertebrse ; and, 
 what is still more worthy of note, in several breeds the whole 
 skull differs in its proportions and outline from that of the 
 rock pigeon. 
 
 So many passages have been traced between the most di- 
 vergent varieties above alluded to and the wild Columba 
 Livia, that ornithologists do not hesitate to recognise this 
 species as the common progenitor of them all. Another 
 curious proof of such a derivation is afforded by crossing dis- 
 tinct breeds and finding in the offspring some peculiar cha- 
 racters of the rock pigeon, especially in the plumage, which 
 neither of the parent races possessed.* Thus the blue slaty 
 colour, or dark bars, on the wings and tail, and the white 
 edging of the outer tail feathers of the original Columba 
 Livia, are produced in the mongrel offspring of the carrier 
 and fan-tail, although all these characters have often been 
 in abeyance in both of the parent stocks for a hundred or 
 more generations. Mr. Darwin has tested the truth of this 
 singular principle of atavism, by experiment, in the case of 
 pigeons, and has also obtained analogous results, by pairing 
 some of the most distinct varieties of the common fowl; 
 as, for example, a black Spanish cock and a white silky hen, 
 two ancient and pure breeds in which there was not a trace 
 of the red colour proper to the plumage of the wild Gallus 
 banJciva, a Himalayan species, which has always been sup- 
 posed to be the original of our domestic fowls. In many 
 of the young obtained from such a cross the peculiar orange- 
 red colour was conspicuous, f 
 
 Revival of long-lost characters in the offsprings of cross-breeds. 
 Why the act of crossing should tend to evoke characters 
 which had long been lost in each of the parent races, is 
 
 * Darwin ' On Variation,' vol. i. p. 200. f Ibid. p. 241. 
 
CH. XXXVI.] REVIVAL OF CHARACTERS IN CROSS-BREEDS. 291 
 
 one of the most wonderful enigmas which the attributes of 
 inheritance present to us. Bj what favourable combination 
 of circumstances can we suppose these characters, which must 
 have been lying latent in so many intermediate generations, 
 to be thus made again to manifest themselves ? In some 
 cases they are developed alternately in successive genera- 
 tions, in others at longer intervals. 
 
 The composition of the molecules which form the germ- 
 cells of animals and plants, and their mode of multipli- 
 cation and transmission from one generation to another, has 
 been a favourite subject of speculation ever since the time of 
 Buff on and Bonnet. More recently (1849), Professor Owen 
 has treated of this subject iu his Memoir on f Parthenogene- 
 sis,' and Mr. Herbert Spencer has speculated on the man- 
 ner in which the atoms or physiological units composing the 
 fertilised germ of an animal or plant may unfold into orga- 
 nisms and become the means of transferring the qualifica- 
 tions of the parent to the offspring.* The new hypothesis 
 suggested by Mr. Darwin, and which he has called ' Pange- 
 nesis,' coincides in many respects with that of Mr. Spencer, 
 and cannot be fully understood without reference to the 
 luminous and detailed explanations of it given by Darwin in 
 the concluding chapters of his new work.f He assumes that 
 the germ-cells of animals and plants are capable of generating 
 minute bodies, termed by him cell-gemmules, which become 
 diffused through all parts of an organism, and are capable of 
 multiplying and uniting with others like themselves, and 
 when this union does not occur, may remain in a dormant 
 state. Their increase may take place after the usual man- 
 ner of growth in all living beings, according to which entii e 
 limbs are sometimes reproduced in the lower animals after 
 they have been cut off, or as wounds are healed by the form- 
 ation of new flesh, or as a portion of the leaf of a plant may 
 be developed into a perfect individual. The cell-gemmules re- 
 maining undeveloped for many generations, may be compared 
 to seeds lying dormant in the earth, or to rudimentary organs 
 which, though useless, may be inherited for an indefinite 
 
 * Principles of Biology, vol. i. chaps, iv. and viii. 
 f Darwin ' On Variation,' chaps, xxxvii. and xxxviii. 
 
 U 2 
 
292 VAKIATION OF PLANTS AND ANIMALS. [Cn. XXXVI. 
 
 succession of generations, or as long as an entire species 
 endures on the earth. 
 
 Before this new hypothesis was started, it was sufficiently 
 difficult to conceive how a microscopic cell or ovule, so minute 
 as to be often invisible to the naked eye, and in some cases 
 requiring the aid of a powerful microscope to be made visible, 
 should contain within it not only the characters of the species 
 but many of the peculiarities of one or both parents, including 
 some of their acquired individual habits and instincts. But 
 now we are called upon, in addition, to imagine that there 
 are innumerable other molecules, in each germ or ovule, in 
 which the characteristics of remote progenitors may also be 
 present. As bearing on the question of the possible minute- 
 ness of particles of organic matter, I shall have to refer in a 
 future chapter, p. 387, to the ten million sporules of a single 
 fungus which were counted by Fries. A still more lively idea 
 of the possible diminutiveness of material atoms may be 
 gained by reflecting on the manner in which the air is often 
 perfumed or tainted throughout large spaces by the odour 
 of a plant or animal, and how the contagious particles of 
 certain diseases float unseen in the atmosphere, until they are 
 at last received within a human body, where they rapidly 
 increase and act powerfully. 
 
 Assuming, then, that the number of cell-gemmules in an 
 undeveloped embryo may be almost infinite in number, we 
 have to explain how some of these, after having been long 
 transmitted in a latent state, may suddenly multiply and gain 
 an ascendancy when individuals belonging to two distinct 
 races are crossed. Among other facts which are somewhat 
 analogous, we are reminded that, although there is frequently 
 in the offspring a fusion of all the characters of the parents, 
 yet occasionally some of the characters of one parent are 
 exclusively transmitted to one of the children and those of 
 the other parent to another. The characters of one parent 
 sometimes prevail in all the offspring to the exclusion 
 of those of the other. When Gartner crossed white and 
 yellow-flowered varieties and species of mullein (verbascum), 
 these colours never became blended, but the offspring bore 
 either pure white or pure yellow blossoms. This must depend 
 
CH. XXXVI. ] MULTIPLE ORIGIN OF THE DOG. 293 
 
 011 some principle of the affinity of similar and the repul- 
 sion of dissimilar atoms. The cell-germs derived from two 
 individuals of distinct races may not readily unite or not 
 in sufficient numbers for the reproduction of the character- 
 istic attributes of the two parents ; they may be antagonistic 
 and neutralise each other's power in such a way as to allow 
 the gemmules derived from a remote progenitor to multiply 
 suddenly, gaining such an ascendancy as to revive certain 
 peculiarities of the original stock which had remained long 
 in abeyance. 
 
 Multiple origin of the dog. In regard to the origin of the 
 various canine races which have been domesticated by man 
 in all parts of the world, there is still no small diversity of 
 opinion. Mr. Darwin, after an elaborate analysis of all that 
 has been written on the subject, inclines to the belief which 
 Pallas entertained of the multiple origin of the dog, more 
 than one wild species having been blended together to pro- 
 duce the very distinct races which we now possess. The 
 celebrated John Hunter maintained that the wolf, the dog, 
 and the jackal were all of one species ; because he had found, 
 by two experiments, that the dog would breed both with the 
 wolf and the jackal ; and that the mule, in each case, would 
 breed again with the dog. In these cases, however, it may 
 be observed, that there was always one parent at least of 
 pure breed, and no proof was obtained that a true hybrid 
 race could be perpetuated. 
 
 It was formerly supposed that the period of gestation in 
 the dog and the wolf differed slightly; but experiments 
 have not borne out this opinion ; and Professor Owen has 
 been unable to confirm the alleged difference in the struc- 
 ture of a part of the intestinal canal. It seems scarcely to 
 admit of a doubt that both the jackal, and more than 
 one species of wolf, have been occasionally crossed with 
 the dog. 
 
 The main argument in favour of the different breeds of the 
 dog being the descendants of distinct wild stocks is their 
 resemblance, says Darwin, in various countries to indigenous 
 
 .* Darwin 'On Variation,' chap. i. p. 20. 
 
294 VAKIATION OF PLANTS AND ANIMALS. [Cn. XXX^ 7 I. 
 
 species still existing there.* Thus the domestic dogs of the 
 American Indians resemble North American wolves. The 
 shepherd-dog of Hungary is very like the European wolf; 
 the domestic dog of Asia resembles the jackal. 
 
 But although the intercrossing of several original wild stocks 
 may have increased the total number and diversity of our 
 breeds, it cannot, says Darwin, explain the origin of such ex- 
 treme forms as thoroughbred greyhounds, bloodhounds, bull- 
 dogs, Blenheim spaniels, terriers and pugs, none of which are 
 known to have been kept by savages, and which are the 
 product of breeding in civilised countries. The difference 
 in the form of the skulls in some of these races is admitted 
 by Cuvier to be sometimes more than generic ; in some 
 varieties there is an additional pair of molars in the upper 
 jaw ; and some, like the Turkish dogs, are deficient in the 
 number of their molars ; the mammae also vary from seven to 
 ten in number. Dogs have properly five toes in front, and four 
 behind, but a fifth toe is often added, together with a fourth 
 cuneiform bone. Man, says Darwin, if he had cared about 
 the number of their molar teeth, mammae or digits, could, by 
 selection, have fixed these characters, in the same way as he 
 has given additional horns to certain breeds of sheep, and an 
 additional toe and feathers to the Dorking fowl ; but at 
 present these peculiarities have merely accompanied changes 
 in form, fleetness, size, strength, and other characters which 
 the breeder has purposely fixed. 
 
 Inherited instincts. It is evident that these new races 
 could not be artificially produced if the individual pecu- 
 liarities of one generation were not transmitted by inheritance 
 to the next. Even newly acquired habits and instincts are 
 often so transmitted, as was beautifully illustrated by a race 
 of dogs employed for hunting deer in the platform of Santa 
 Fe, in Mexico. The mode of attack, observes M. Eoulin, 
 which they employ consists in seizing the animal by the belly 
 and overturning it by a sudden effort, taking advantage of 
 the moment when the body of the deer rests only upon the 
 fore-legs. The weight of the animal thus thrown over is 
 
 * Darwin ' On Variation,' chap. i. p. 20. 
 
CH. XXXVI.] INHERITED INSTINCTS OF DOGS. 295 
 
 often six times that of its antagonist. The dog of pure 
 breed inherits a disposition to this kind of chase, and never 
 attacks a deer from before while running. Even should the 
 deer, not perceiving him, come directly upon him, the dog 
 steps aside and makes his assault on the flank ; whereas 
 other hunting dogs, though of superior strength, and general 
 sagacity, which are brought from Europe, are destitute of 
 this instinct. For want of similar precautions, they are 
 often killed by the deer on the spot, the vertebrae of their 
 neck being dislocated by the violence of the shock.*" 
 
 A new instinct has also become hereditary in a mongrel 
 race of dogs employed by the inhabitants of the banks of 
 the Magdalena almost exclusively in hunting the white- 
 lipped pecari. The address of these dogs consists in re- 
 straining their ardour, and attaching themselves to no animal 
 in particular, but keeping the whole herd in check. Now, 
 among these dogs some are found, which the very first time 
 they are taken to the woods, are acquainted with this mode 
 of attack ; whereas, a dog of another breed starts forward at 
 once, is surrounded by the pecari, and, whatever may be his 
 strength, is destroyed in a moment. 
 
 Some of our countrymen, engaged about the year 1825 
 in conducting one of the principal mining associations in 
 Mexico, that of Real del Monte, carried, out with them some 
 English greyhounds of the best breed, to hunt the hares 
 which abound in that country. The great platform which 
 is here the scene of sport is at an elevation of about 
 9,000 feet above the level of the sea, and the mercury in 
 the barometer stands habitually at the height of about nine- 
 teen inches. It was found that the greyhounds could not 
 support the fatigues of a long chase in this attenuated 
 atmosphere, and before they could come up with their prey, 
 they lay down gasping for breath ; but these same animals 
 have produced whelps which have grown up, and are not in 
 the least degree incommoded by the want of density in the 
 air, but run down the hares with as much ease as the fleetest 
 of their race in this country. 
 
 The fixed and deliberate stand of the pointer has with 
 
 * M. Eoulin, Ann. des. Sci. Nat., torn. xvi. p. 16. 1829. 
 
296 VARIATION OF PLANTS AND ANIMALS. [On. XXXVI. 
 
 propriety been regarded as a mere modification of a habit, 
 which may have been useful to a wild race accustomed to 
 wind game, and steal upon it by surprise, first pausing for an 
 instant, in order to spring with unerring aim. The faculty 
 of the retriever, however, may justly be regarded as more 
 inexplicable and less easily referable to the instinctive 
 passions of the species. M. Majendie, says a French writer 
 in a recently published memoir, having learnt that there was 
 a race of dogs in England which stopped and brought back 
 game of their own accord, procured a pair, and, having 
 obtained a whelp from them, kept it constantly under his 
 eyes, until he had an opportunity of assuring himself that, 
 without having received any instruction, and on the very 
 first day that it was carried to the chase, it brought back 
 game with as much steadiness as dogs which had been 
 schooled into the same manoeuvre by means of the whip and 
 collar. 
 
 The power of man to produce new races of animals by 
 selection, has been by no means confined to the mammalia 
 and birds. The Chinese have kept gold fish (Cyprinus aura- 
 tus) for ornament or curiosity from a remote period, and 
 it is suspected that the golden colour is not characteristic 
 of the species in a state of nature. Yarrell mentions that 
 descriptions and coloured drawings of no less than 89 varie- 
 ties have been given by Sauvigny, some destitute of dorsal 
 fins, others having a double anal fin or a triple tail. Of 
 these, many, says Darwin, may be called monstrosities, for 
 it is difficult to draw a strict line between a variation and a 
 monstrosity. 
 
 If we turn from the vertebrata to the invertebrata, we find 
 here again that selection is capable of producing distinct 
 races in the class of insects, as in the case of the common 
 silk-moth (Bombyx mori), which is believed to have been do- 
 mesticated in China nearly 3,000 years before our era. It 
 was brought to Constantinople in the sixth century, whence 
 it was carried into Italy, and in the year 1494 into France."* 
 
 * Godron ' De 1'Espece,' 1859, torn. i. p. 460; and see Darwin 'On Varia- 
 tion,' vol. i. p. 300. 
 
CH. XXXVI.] PARTICULAR PARTS ONLY ALTERED. 297 
 
 The nature of the food given to the caterpillar influences to 
 a certain extent the character of the breed. Great care is 
 taken in India and Europe in the selection of the eggs of 
 moths the caterpillars of which have produced the best 
 cocoons. The silk is usually yellow, but sometimes white, 
 and, by careful selection, in the course of sixty-five genera- 
 tions the proportion of yellow cocoons in France was greatly 
 reduced. The abdominal feet of the caterpillars which yield 
 white cocoons are, according to Quatrefages, always white, 
 while the feet of those which give yellow cocoons are in- 
 variably yellow, and there is a corresponding difference in the 
 tint of the eggs. 
 
 Man causes particular parts of an animal or plant to vary 
 while other parts may continue unaltered. The possibility of 
 obtaining particular breeds and fixed varieties of animals and 
 plants depends on the fact that variations occur in almost 
 any required direction if a vast number of individuals are 
 produced. It is also found that one form of variation may 
 usually be accumulated in successive generations by selection, 
 without the other characters of the species being materially 
 affected. Cows are wanted which may give us an increased 
 quantity of milk, sheep which may yield finer wool, poultry 
 which may have a habit of continually laying eggs ; and these 
 qualities are often obtained without perceptibly changing in 
 any other respect the habits or organisation of the same 
 races. 
 
 In the case of the maize and the vine, we alter the seed 
 and the fruit without changing the leaves, whereas in the 
 foliage of the mulberry, cultivated for the sake of the silk- 
 worm, new varieties have been formed, the fruit remaining 
 the same. In. the cabbage the leaves have undergone 
 wonderful transformations, as have the tubers in the potato 
 and the roots in the carrot, while the characters of the flowers 
 in all have remained unaltered. The modifications produced 
 in the seeds of the maize deserve especial notice. The 
 different races vary in height from eighteen inches to as 
 many feet, and the whole ear in one variety is more than 
 four times as long as in another dwarf kind. The seeds 
 are coloured white, pale yellow, orange, red, violet, or 
 
298 VAKIATION OF PLANTS AND ANIMALS. [On. XXXVI. 
 
 streaked with, black. Mr. Darwin found that a single 
 grain in one variety equalled in weight seven grains of 
 another. The tall kinds grown in southern latitudes and 
 exposed to great heat require from six to seven months 
 to ripen their seed, whereas the dwarf kinds grown in 
 northern and colder climates require only from three to four 
 months."* 
 
 In North America the maize has been gradually cultivated 
 farther and farther northward, in which case the changes 
 induced by an alteration of climate have been added to 
 those due to selection. In this plant the results of in- 
 herited acclimatisation are very striking. Metzger obtained 
 the seed of a variety called Zea altissima from the warmer 
 parts of America, and raised it in Germany, and the first 
 year the plants were twelve feet high and few seeds were 
 perfected. The lower seeds in the ear kept true to their 
 proper form, but the upper ones became slightly changed. 
 In the second generation the plants were from nine to ten 
 feet in height, and the seeds had changed from white to yellow 
 and were more rounded in form. In the third generation 
 nearly all resemblance to the original and very distinct 
 parent form was lost. In the sixth generation this maize, 
 which continued to be cultivated near Heidelberg, could 
 only be distinguished from the common European kind by 
 a somewhat more vigorous growth. c The fact,' says Mr. 
 Darwin, ' affords the most remarkable instance known to me 
 of the direct and prompt action of climate on a plant.' 
 
 Several hundred varieties of the vine, each characterised 
 by differences in their fruit, have been reared in hothouses, 
 or cultivated for wine, while the mulberry, both in France 
 and India, has given rise to as many varieties in the texture 
 and quality of the leaves, characters which have been ren- 
 dered constant by selection. If man had reversed this treat- 
 ment he might doubtless have produced endless changes 
 in the leaves of the vine, the grapes remaining unaltered, 
 and a great many races characterised by different fruits in 
 the mulberry, while the leaves, being neglected, would not 
 
 * Metzger die Getreidearten, 1841, p. 206, cited by Darwin ' On Variation,' 
 vol. i. p. 321. 
 
CH. XXXVI.] CHANGES PRODUCED IN CULTIVATED PLANTS. 299 
 
 have undergone any marked modification from the type of 
 the original plant. 
 
 A bitter plant (Brassica oleracea), with wavy green sea 
 leaves, having a flower like mustard or wild charlock, has been 
 taken from the sea-side, and transplanted into the garden, 
 where it has lost its saltness, and has been metamorphosed 
 into many distinct vegetables, among others the red cabbage 
 and the cauliflower, which are as unlike each other as is 
 each to the parent plant. In certain countries plants belong- 
 ing to the order of Cruciferse which are generally herbaceous 
 become developed into trees, so the cabbage in the island of 
 Jersey has acquired a woody stem not unfrequently from ten 
 to twelve feet in height. The stalk of one which measured 
 sixteen feet in height had its spring shoots at the top occu- 
 pied by a magpie's nest. The wood of the same variety 
 is sometimes used for walking sticks, and even for rafters. 
 These effects result from particular culture and peculiarities 
 of climate. What is worthy of note, says Darwin, is the very 
 trifling difference in the flowers, seed-pods, and seeds of the 
 cabbage which accompanies the wonderful metamorphosis 
 which man has brought about in the shape, size, colour, and 
 growth of the leaves and stem. What a contrast is here 
 presented to the changes in the corresponding parts in the 
 varieties of maize and wheat. ' The explanation is obvious : 
 the seeds alone are valued in our cereals, and their variations 
 have been selected ; whereas the seeds, seed-pods, and flowers 
 have been utterly neglected in the cabbage, whilst many 
 useful variations in their leaves and stems have been noticed 
 and preserved from an extremely remote period, for cabbages 
 were cultivated by the old Celts. '* 
 
 Among the changes in external conditions of which florists 
 avail themselves in order to produce new varieties those of 
 the soil must not be overlooked. The production of blue 
 instead of red flowers in the Hydrangea liortensis, illustrates 
 the immediate effect of certain soils on the colours of the 
 calyx and petals. In garden-mould or compost, the flowers 
 are invariably red; in some kinds of bog-earth they are 
 
 * Darwin ' On Variation,' vol. i. p. 324. 
 
300 VAKIATION OF PLANTS AND ANIMALS. [On. XXXVI. 
 
 blue ; and the same change. is always produced by a particular 
 sort of yellow loam. 
 
 Whether there are definite limits to the variability of a 
 species. In former editions of this work (from 1831 to 1853),* 
 I contended that there are limits to that deviation from an 
 original type of which species are susceptible. My argu- 
 ment was founded chiefly on the rapid rate at which we may 
 bring about considerable modifications in a brief period in 
 domesticated animals and cultivated plants, and the slow 
 progress which we can afterwards make in modifying the 
 same races when our experiments are persevered in for a 
 great many generations. In illustration of this principle I 
 observed, that when man uses force or stratagem against 
 wild animals, the persecuted race soon becomes more 
 cautious, watchful, and cunning ; new instincts seem, often to 
 be developed, and to become hereditary in the first two or 
 three generations : but let the skill and address of man in- 
 crease, however gradually, no farther variation can take place, 
 no new qualties are elicited by the increasing dangers. The 
 alteration of the habits of the species has reached a point 
 beyond which no ulterior modification is possible, however 
 indefinite the lapse of ages during which the new circum- 
 stances operate. Extirpation then follows, rather than such 
 a transformation as could alone enable the species to perpe- 
 tuate itself under the new state of things. 
 
 But in the first place Mr. Darwin has shown that even 
 in those species such as the pigeon, our common cattle, 
 sheep or pigs, which have been made to vary by selection 
 from the remotest periods, there are no signs of a positive 
 limit having been reached beyond which no farther change 
 can be brought about. All have been altered within quite 
 modern times, and c the tendency to general variability seems 
 unlimited. 'f 
 
 It has also been pertinently remarked by Mr. Wallace that 
 the amount of change in any one direction may at first be 
 comparatively rapid ; as when in the case of the race-horse, 
 
 * 'Principles of Geology,' 1st edi- 9th edition, chap. xxxv. p. 592. 
 tion, 1831, vol. ii. chap. iii. p. 37, and f Darwin ' On Variation/ &c., p. 416. 
 
CH. XXXVI.] OBEDIENCE TO MAN OFTEN AN INSTINCT. 301 
 
 we begin to select certain varieties with a view of increasing 
 speed, and afterwards fail in our efforts materially to raise the 
 standard, for how ever many years we may expend wealth and 
 energy in the attempt. The real question, he observes, is 
 not whether indefinite and unlimited change in any or all 
 directions is possible, but whether man can bring about such 
 differences as do occur in nature by accumulating variations 
 or by selection. ' All the swiftest animals deer, antelopes, 
 hares, foxes, lions, leopards, horses, zebras, and many others 
 have reached very nearly the same degree of speed. Although 
 the swiftest of each must have been for ages preserved and the 
 slowest must have perished, we have no reason to believe that 
 there is any advance of speed. The possible limits under 
 existing conditions, and perhaps under possible terrestrial 
 conditions, has been long reached.'* But in the English race- 
 horse we have been enabled to produce a variety surpassing 
 in swiftness its own wild progenitor and all the other equine 
 species. 
 
 Obedience to man under domestication often a mere adaptation 
 of a natural instinct. We may also very easily exaggerate the 
 amount of change which seems to be brought about in a few 
 generations. Frederick Cuvierf has clearly pointed out one 
 source of deception relating to alterations which we may fancy 
 we have wrought in the instincts and dispositions of animals. 
 An animal in domesticity, he observes, is not essentially in a 
 different situation, in regard to the feeling of restraint, from one 
 left to itself. It lives in society without constraint, because, 
 without doubt, it was a social animal ; and it conforms itself to 
 the will of man, because it had a chief, to which, in a wild 
 state, it would have yielded obedience. There is nothing in 
 its new situation that is not conformable to its propensities ; 
 it is satisfying its wants by submission to a master, and 
 makes no sacrifice of its natural inclinations. All the social 
 animals, when left to themselves, form herds more or less 
 numerous ; and all the individuals of the same herd know 
 each other, are mutually attached, and will not allow a strange 
 
 * "Wallace, Quart. Journ. of Science, Jameson, Ed. New Phil. Journ., Nos. 6 
 October, 1867, p. 486. 7, 8. 
 
 f Mem. du Mus. d'Hist. Nat. ; 
 
302 VAKIATION OF PLANTS AND ANIMALS. [On. XXXVI. 
 
 individual to join them. In a wild state, moreover, they 
 obey some individual, which, by its superiority, has become 
 the chief of the herd. Our domestic species had, originally, 
 this sociability of disposition ; and no solitary species, how- 
 ever easy it may be to tame it, has yet afforded true domestic 
 races. We merely, therefore, develope, to our own advantage, 
 propensities which propel the individuals of certain species 
 to draw near to their fellows. 
 
 The sheep which we have reared is induced to follow us, as 
 it would be led to follow the flock among which it was 
 brought up ; and, when individuals of gregarious species 
 have been accustomed to one master, it is he alone whom 
 they acknowledge as their chief he only whom they obey. 
 6 The elephant allows himself to be directed only by the 
 carnac whom he has adopted ; the dog itself, reared in solitude 
 with its master, manifests a hostile disposition towards all 
 others ; and everybody knows how dangerous it is to be in 
 the midst of a herd of cows, in pasturages that are little fre- 
 quented, when they have not at their head the keeper who 
 takes care of them. 
 
 Everything, therefore, tends to convince us, that formerly 
 men were only, with regard to the domestic animals, what 
 those who are particularly charged with the care of them 
 still are namely, members of the society which these animals 
 form among themselves ; and, that they are only distinguished, 
 in the general mass, by the authority which they have been 
 enabled to assume from their superiority of intellect. Thus, 
 every social animal which recognises man as a member, and 
 as the chief of its herd, is a domestic animal. It might even 
 be said, that, from, the moment when such an animal admits 
 man as a member of its society, it is domesticated, as man could 
 not enter into such a society without becoming the chief of it.'* 
 But the ingenious author whose observations I have here 
 cited, admits that the obedience which the individuals of 
 many domestic species yield indifferently to every person, is 
 without analogy in any state of things which could exist 
 previously to their subjugation by man. Each troop of wild 
 horses, it is true, has some stallion for its chief, who draws 
 
 * Mem. du Mus. d'Hist. Nat. 
 
CH. XXXVI.] OKIGINAL TAMENESS OF ANIMALS. 303 
 
 after him all the individuals of which the herd is composed ; 
 but, when a domesticated horse has passed from hand to 
 hand, and has served several masters, he becomes equally 
 docile towards any person, adopting as it were the whole 
 human race as his leader. 
 
 Every troop of wild elephants has a leader who directs 
 their movements with much caution, and takes care that 
 none of them straggle from the herd. In India this animal 
 rarely breeds in captivity, although, according to Mr. Craw- 
 furd, in Ava, where the females are allowed to roam some- 
 what freely in the forests, they breed in a half-domestic 
 state. In general it is found to be the best economy to 
 capture full-grown individuals in a wild state, and in a few 
 years after they are taken, sometimes, it is said, in a few 
 months, their education is completed. They who have had 
 opportunities of observing them in their native forests are 
 by no means surprised at the sagacity which they display 
 after they have accommodated themselves to the society of 
 man, to whom they render obedience, not by acquiring any 
 new instincts, but simply in conformity to faculties proper to 
 them in a wild state. 
 
 The tameness of some animals, in the case of cattle, 
 goats, and deer for example, after they have been reclaimed 
 and improved by selection for two or three generations, is 
 another change of which we may be in danger of overrating 
 the importance. The first savages who wandered into new 
 districts probably found most of the animals free from any 
 apprehension of danger from man. Mr. Darwin relates that 
 in the islands of the Galapagos archipelago, placed directly 
 under the equator, and nearly 600 miles west of the American 
 continent, all the terrestrial birds, as the finches, doves, 
 hawks, and others, are so tame that they may be killed with 
 a switch. One day, says this author, c a mocking-bird 
 alighted on the edge of a pitcher which I held in my hand, 
 and began quietly to sip the water, and allowed me to lift 
 it with the vessel from the ground.' Yet formerly, when 
 the first Europeans landed, and found no inhabitants in these 
 islands, the birds were even tamer than now : already they 
 are beginning to acquire that salutary dread of man which 
 
304 VAEIATION OF PLANTS AND ANIMALS. [Cn. XXXVI. 
 
 in countries long settled is natural even to young birds, 
 which have never received any injury. So in the Falkland 
 Islands, both the birds and foxes are entirely without fear of 
 man ; whereas, in the adjoining mainland of South America, 
 many of the same species of birds are extremely wild; for 
 there they have for ages been persecuted by the natives.*" 
 
 Dr. Richardson informs us, in his able history of the 
 habits of the North American animals, that, 6 in the retired 
 parts of the mountains where the hunters had seldom pene- 
 trated, there is no difficulty in approaching the Rocky Moun- 
 tain sheep, which there exhibit the simplicity of character so 
 remarkable in the domestic species ; but where they have been 
 often fired at, they are exceedingly wild, alarm their com- 
 panions, on the approach of danger, by a hissing noise, and 
 scale the rocks with a speed and agility that baffle pursuit. 'f 
 
 ' Feral ' varieties do not revert to the exact likeness of the 
 original stock. It is an old and received opinion that if any 
 domesticated animals or cultivated plants are abandoned by 
 man and allowed to run wild or become ' feral,' they will 
 revert to the exact likeness of their aboriginal parent stock. 
 But this seems to be only true to a limited extent. It was 
 before remarked (p. 281) that such c feral ' animals can only 
 compete with their fellows in the struggle for life by losing 
 most of the characters which they have acquired in a state 
 of domesticity. 
 
 Our quickly fattening pigs, says Mr. Wallace, our short- 
 legged sheep, cattle without horns and pouter pigeons, would 
 soon be annihilated if man's protection was withheld from 
 them. In a few generations the boar when compelled to search 
 for food recovers his long tusks and the full exercise of all his 
 organs ; reverting in the general shape of his body, the length 
 of his legs and of his muzzle, to the type of the wild boar. 
 
 His reversion to the likeness of the parent stock, says 
 Darwin, is probably more complete than that of other 
 domesticated animals which run wild, but there is no evi- 
 dence to show that it is ever perfect. There are two main 
 types of the domestic pig one supposed to come from the 
 
 * Darwin's Journ. in Voyage of H.M.S. f Fauna Boreali Americana, p. 273. 
 
 Beagle, p. 475. 
 
CH. XXXVI.] THE HYBRIDISATION OF PLANTS. 305 
 
 European Sus scrofa, and the other from the Indian Sus 
 Indica. These ^aridties or species seem not yet to have been 
 distinctly recognised in a feral state, and the feral pigs of S. 
 America, Jama!- a/ and New Granada have each some pecu- 
 liarities.* Undey new climatal and other conditions they vary, 
 but they can only stand their ground by reacquiring many 
 lost characters which belonged to the original wild species. 
 
 It is very commonly believed that when the seeds of fruit- 
 trees and garden vegetables spring up in uncultivated soils, the 
 plants revert to the likeness of the original wild stock ; but Dr. 
 Hooker observes that this is not strictly true. i They degene- 
 rate and sometimes die out ; sometimes they become stunted, 
 and so far resemble their wild progenitors, but they do not re- 
 vert to the original type. Thus the Scotch kail and Brussels 
 sprouts, if neglected, become as unlike the wild Brassica Ole- 
 racea as they are unlike one another ; and our finer kind of 
 apples, if grown from seed, degenerate and become crabs, but 
 in so doing, they become crab states of the varieties to which 
 they belong, and do not revert to the original wild crab-apple ; 
 and the same, is true to a great extent of cultivated roses, 
 and of the raspberry, strawberry, and most garden fruits.' f 
 This experienced botanist therefore concludes that the cha- 
 racters of a variety are never so entirely obliterated that it 
 has no longer a claim to be considered a variety. 
 
 How far do domestic races differ from wild species in their 
 capacity to interbreed Hybridisation of animals and plants. 
 It is now time to return to a question which was mooted at 
 the commencement of this chapter, namely, the freedom with 
 which all artificially produced races breed together, and how 
 far this clearly constitutes a real difference between them and 
 the most closely allied wild species. 
 
 There are no less than 288 wild species of the pigeon 
 family (Golumbidce) ; J yet, although some of these approach 
 very near to others in their characters, they will not, so far as 
 experiments have yet been tried, pair together, presenting 
 in this respect a marked contrast to those domestic races 
 which, as before stated (p. 289), would, if found wild, have 
 
 * Darwin ' On Variation,' chap. iii. J. C. L. Bonaparte, cited by Darwin 
 
 f Hooker, 'Flora of Australia,' p. ix. 'On Variation,' p. 133. 
 
 VOL. II. X 
 
306 VARIATION OF PLANTS ANIMALS. [Cn. XXXVI. 
 
 been ranked by ornithologists as trn les, yet which pair 
 
 freely and produce fertile offspring-. 
 
 All the different races of domestic dogs breed together, 
 and John Hunter's opinion has already been cited, that the 
 jackal and wolf must be classed as of the same species 
 because when crossed they produce fertile mules. A ca- 
 pability of thus breeding together has often been proposed, 
 as the best practical test of a real distinctness of species. 
 The experiment with which we are most familiar relates to 
 the mixed offspring of the horse and the ass ; and in this 
 case it is well established that the he-mule can generate, and 
 the she-mule produce. Such cases occur in Spain and Italy, 
 and much more frequently in the West Indies and New 
 Holland ; but these mules have never bred in cold climates, 
 seldom in warm regions, and still more rarely in temperate 
 countries. But no instance is known of two such mules, 
 male and female, having 'bred together. 
 
 The hybrid offspring of the she-ass and the stallion, the 
 yivvo? of Aristotle, and the hinnus of Pliny, differs from the 
 mule, or the offspring of the ass and mare. In both cases, 
 says Buffon, these animals retain more of the dam than of 
 the sire, not only in the magnitude, but in the figure of the 
 body ; whereas, in the form of the head, limbs, and tail, they 
 bear a greater resemblance to the sire. It seems rarely to 
 happen that any hybrids are truly intermediate in character 
 between the two parents. Thus Hunter mentions that, in 
 his experiments with the dog and the wolf, one of the 
 hybrid pups resembled the wolf much more than did the rest 
 of the litter ; and we are informed by Wiegmann, that, in a 
 litter obtained in the Eoyal Menagerie at Berlin, from a white 
 pointer and a she-wolf, two of the cubs resembled the common 
 wolf-dog, but the third was like a pointer with hanging ears. 
 
 The phenomena of hybridity in plants present a remarkable 
 parallel to those in the animal kingdom ; and we have learnt 
 more from the cultivators of plants, because they have been 
 able to conduct their experiments on a grander scale, sowing 
 great numbers of the two species which they desire to cross, 
 and taking small account of failures, provided that some of 
 the results of crossing are successful. 
 
CH. XXXVI.] . THE HYBEIDISATION OF PLANTS. 307 
 
 The first accurate experiments in illustration of this curious 
 subject appear to have been made by K61 renter, who ob- 
 tained a hybrid from two species of tobacco, Nicotiana rustica 
 and N. paniculata, which differ greatly in the shape of their 
 leaves, the colour of the corolla, and the height of the stem. 
 The stigma of a plant of N. rustica was fertilised with the 
 pollen of a plant of N. paniculata. The seed ripened, and 
 produced a hybrid which was intermediate between the two 
 parents, and which, like all the hybrids which this botanist 
 brought up, had imperfect stamens. He afterwards impreg- 
 nated this hybrid with the pollen of N. paniculata, and 
 obtained plants which much more resembled the last. This 
 he continued through several generations, until, by due per- 
 severance, he actually changed the Nicotiana rustica into the 
 Nicotiana paniculata. 
 
 The plan of crossing adopted, was the cutting off of the 
 anthers of the plant intended for fructification before they 
 had shed pollen, and then laying on foreign pollen upon the 
 stigma. The same experiment has since been repeated with 
 success by Wiegmann, who found that he could bring back 
 the hybrids to the exact likeness of either parent, by crossing 
 them a sufficient number of times, with individuals of one of 
 the pure stocks. 
 
 The blending of the characters of the parent stocks, in 
 many other of Wiegmann' s experiments, was complete ; the 
 colour and shape of the leaves and flowers, and even the 
 scent, being intermediate, as in the offspring of the two 
 species of verbascum. An intermarriage, also, between the 
 common onion and the leek (Alliumcepa and -4. porrum) gave 
 a mule plant, which, in the character of its leaves and flowers, 
 approached most nearly to the garden onion, but had the 
 elongated bulbous root and smell of the leek. 
 
 The same botanist remarks, that vegetable hybrids, when 
 not strictly intermediate, more frequently approach the female 
 than the male parent species ; but they never exhibit characters 
 foreign to both. A re-cross with one of the original stocks 
 generally causes the mule plant to revert towards that stock; 
 but this is not always the case, the offspring sometimes con- 
 tinuing to exhibit the character of a full hybrid. 
 
308 VAKIATION OF PLANTS AND ANIMALS. [On. XXXVI. 
 
 Gartner, in his work on the hybridisation of plants, has 
 shown that some pure species which can be united with 
 unusual facility, will produce sterile hybrids, while others 
 which are crossed rarely., or with extreme difficulty, produce 
 hybrids which are very fertile, as for example in different 
 species of the genus Dianthus or pink. The same botanist 
 repeatedly crossed the common red and blue pimpernels, 
 Anagallis arvensis and A. ccerulea, which, says Darwin, the 
 best naturalists rank as mere varieties of one species, and 
 found them absolutely sterile. These plants, besides their 
 distinctness in colour, differ slightly in the nervation of their 
 leaves and in the shape of their petals ; and botanists who 
 attach importance to the test of sterility, conclude that they 
 are specifically distinct, although scarcely any of them would 
 have come to such an opinion before the experiment of cross- 
 ing had been tried. 
 
 Wiegmann diversified as much as possible his mode of 
 bringing about these irregular unions among plants. He 
 often sowed parallel rows, near to each other, of the species 
 from which he desired to breed ; and, instead of mutilating, 
 after Kolreuter's fashion, the plants of one of the parent 
 stocks, he merely washed the pollen off their anthers. The 
 branches of the plants in each row were then gently bent 
 towards each other and intertwined; so that the wind, and 
 numerous insects, as they passed from the flowers of one to 
 those of the other species, carried the pollen and produced 
 fecundation. 
 
 When we consider how busily many insects are engaged 
 in conveying anther-dust from flower to flower, especially 
 bees, flower- eating beetles, and the like, it seems a most 
 enigmatical problem how it can happen that promiscuous 
 alliances between distinct species are not perpetually oc- 
 curring. 
 
 How continually do we observe the bees diligently em- 
 ployed in collecting on their hind legs the red and yellow 
 powder by which the stamens of flowers are covered, and 
 after passing from, one flower to another, carrying it to 
 their hive for the purpose of feeding their young ! In 
 thus providing for their own progeny, these insects assist 
 
CH. XXXVI. ] THE HYBRIDISATION OF PLANTS. 309 
 
 materially the process of fructification.* Few persons need 
 be reminded that the stamens in certain plants grow on 
 different blossoms from the pistils ; and, unless the summit of 
 the pistil be touched with the fertilising dust, the fruit does 
 not swell, nor the seed arrive at maturity. It is by the help 
 of bees, moths, and other insects, that the development of 
 the fruit of many such species is secured, the powder which 
 they have collected from the stamens being unconsciously 
 left by them in visiting the pistils. 
 
 A vast majority of plants are hermaphrodite, yet Mr. 
 Darwin, following up the views suggested by Andrew Knight, 
 has proved experimentally that even with such plants the 
 intermarriage of two separate individuals gives more vigour 
 and fertility to the offspring than if the female organs are 
 fertilised by the pollen of males of the same individual. The 
 whole arrangement of the flower may seem to be made for 
 the purpose of close interbreeding, and yet insects and other 
 means are employed by nature for crossing the hermaphrodite 
 with another individual of the same species. 
 
 How often, during the heat of a summer's day, do we see 
 the males of dioecious plants, such as the yew-tree, standing 
 separate from the females, and sending off into the air, upon 
 the slightest breath of wind, clouds of buoyant pollen ! That 
 the zephyr should so rarely intervene to fecundate the plants 
 of one species with the anther-dust of others, seems almost to 
 realise the converse of the miracle believed in by the credulous 
 herdsmen of the Lusitanian mares 
 
 Ore omnes versse in Zephyrum, slant mpibus altis 
 Exceptantque leves auras: et ssepe sine ullis 
 Conjugiis, vento gravidse, mirabile dictu.f 
 
 Mr. Darwin has discovered that when a flower is fertilised 
 by the wind, it never has a gaily coloured corolla ; but when 
 its fertilisation depends on the aid of insects, the flowers are 
 conspicuous in colour and size, evidently in order to attract 
 their observation.! 
 
 When we consider the facility with which the skilful 
 
 * See Barton ' On Geography of f Georg. lib. iii. 273. 
 
 Plants,' p. 67. } Origin of Species, 4th edition, p. 239. 
 
3-10 VARIATION OF PLANTS AND ANIMALS. [Cn. XXXVI. 
 
 gardener produces hybrid races, it seems strange that we do 
 not offcener meet with hybrids in a state of nature. But it 
 must be remembered that the conditions in the two cases are 
 very different. 
 
 The stigma imbibes, slowly and reluctantly, the granules 
 of the pollen of another species, even when it is abundantly 
 covered with it ; and if it happen that, during this period, 
 ever so slight a quantity of the anther-dust of its own species 
 alight upon it, this is instantly absorbed, and the effect of the 
 foreign pollen destroyed. Besides, it does not often happen 
 that the male and female organs of fructification, in different 
 species, arrive at a state of maturity at precisely the same 
 time. Even where such synchronism does prevail, so that a 
 cross impregnation is effected, the chances are very numerous 
 against the establishment of a hybrid race. 
 
 The greater part even of those seeds of wild plants which 
 are well ripened are either eaten by insects, birds, and other 
 animals, or decay for want of room and opportunity to ger- 
 minate. Unhealthy plants are the first which are cut off by 
 causes prejudicial to the species, being usually stifled by more 
 vigorous individuals of their own kind. If, therefore, the re- 
 lative fecundity or hardiness of hybrids be in the least degree 
 inferior, they cannot maintain their footing for many gener- 
 ations in a wild state. In the universal struggle for existence, 
 the right of the strongest must eventually prevail ; and the 
 strength and durability of a race depends in a great degree 
 on its prolificness, in which hybrids are acknowledged to be 
 generally deficient. 
 
 It is admitted on all hands, that in proportion as the species 
 of animals and plants are remote from each other in structure 
 they are averse to sexual union ; and that species which the 
 zoologist and botanist would usually class as distinct, most 
 commonly refuse to unite, and if they can be crossed and 
 produce new offspring, the hybrids are sterile. Whenever we 
 find that two races regarded by many as true species will 
 produce fertile hybrids, we are reduced to the dilemma of 
 choosing between two alternatives ; either to reject the test 
 of hybridity, or to declare that the two species, from the 
 union of which the fruitful progeny has sprung, were mere 
 
CH. XXXVI.] DIFFEEENT EACES OF CATTLE HEED APAET. 311 
 
 varieties. If we prefer the latter, we are compelled to ques- 
 tion the reality of the distinctness of all other supposed 
 species which differ no more than the parents of such pro- 
 lific hybrids ; for although we may not be enabled immedi- 
 ately to procure, in all such instances, a fruitful offspring, 
 yet experiments show, that sometimes after repeated failures, 
 the union of two recognised species may at last, under very 
 favourable circumstances, give birth to a fertile progeny. 
 
 Two kinds of pheasant, our common species, Phasianus 
 colchicus, and P. torquatus, breed together, and the hybrids 
 are perfectly fertile.* The two pimpernels, as before stated 
 (p. 308), cannot be crossed. 
 
 Tendency of different races of domestic cattle and sheep to herd 
 apart. Although more than one species of wolf as well as the 
 jackal have been crossed with the dog, and this mixture is sup- 
 posed to have contributed somewhat to the great diversity 
 of our artificial breeds, yet these same wolves and the jackal 
 keep distinct in a wild state. So also more than one of the 
 aboriginal races or subspecies of European wild cattle, which 
 kept distinct in prehistoric times, have now been blended 
 and confounded together, and even the humped cattle of 
 India have been crossed with our domestic varieties and have 
 produced fertile offspring. Two species of wild pig, as before 
 stated, the European Sus Scrofa and the Sus Indica, have also 
 been confounded together in some of our domestic races. 
 Yet there is every reason to believe that such mixtures would 
 not have occurred in a state of nature. This may be ex- 
 plained simply by the preference which animals exhibit to 
 unite with others of the same race rather than with those 
 which differ considerably from them. 
 
 In Paraguay the horses have much freedom, and those of 
 the native race of the same colour and size prefer associating 
 together rather than with other imported horses. Three 
 distinct sub-races of the horse in Circassia^ whilst living nearly 
 a free life, refrain almost always from crossing. It has 
 been observed in a district stocked with heavy Lincoln- 
 shire and light Norfolk sheep, that both kinds will, when 
 
 * Origin of Species, 4th edition, p. 300. 
 
312 VARIATION OF PLANTS AND ANIMALS. [Cn. XXXVI. 
 
 they are all turned out together, in a very short time separ- 
 ate to a sheep ; ' the Lincolnshires drawing off to the rich 
 soil, and the Norfolks to their own dry light soil ; and as long 
 as there is plenty of grass 6 the two breeds keep themselves as 
 distinct as rooks and pigeons. In this case different habits 
 of life tend to keep the races distinct.'* 
 
 The origin of a new race of sheep, recorded in the Phi- 
 losophical Transactions for 1813, also illustrates the disposi- 
 tion of even closely related varieties to herd apart, and has 
 also been cited by Professor Huxley as proving the strong 
 tendency which there is in a newly arisen variety to be per- 
 petuated. ' A farmer in Massachusetts possessed a flock of 
 fifteen ewes and a ram of the ordinary kind. In the year 
 1791 one of the ewes presented her owner with a male lamb, 
 differing from its parents by a proportionally long body and 
 short bandy legs, whence it was unable to emulate its rela- 
 tives in those sportive leaps over the neighbouring fences, in 
 which they were in the habit of indulging much to the good 
 farmer's vexation. His neighbours imagined that it would 
 be an excellent thing if all his sheep were endued with the 
 stay-at-home tendencies enforced by nature upon the newly 
 arrived ram, and they advised Wright to kill the old patriarch 
 of his fold and instal the Ancon ram in his place. The result 
 justified their sagacious anticipations. The young lambs 
 were almost always pure Ancons or pure ordinary sheep, and 
 when sufficient Ancon sheep were obtained to interbreed with 
 one another, it was found that the offspring was always pure 
 Ancon. In this well-authenticated instance we have a dis- 
 tinct race established at once or by a leap, and that race 
 breeding true. When the Ancon sheep were herded with 
 other sheep they kept together, so that it was believed that 
 this breed might have been indefinitely protracted, had it not 
 been superseded by the introduction of the Merino sheep, 
 which were not only superior to the Ancons in wool and 
 meat, but were equally quiet and orderly. 'f 
 
 Pallas on domesticity eliminating sterility. Correlation of 
 
 * Darwin ' On Variation,' chap. xvi. Article on Darwin * On the Origin of 
 p. 102, who cites "Marshall. Species.' 
 
 t Huxley, Westminster EeTiew, 1860. 
 
CH. XXXVI.] DOMESTICITY ELIMINATES STERILITY. 313 
 
 growth. Pallas has remarked that domesticity eliminates the 
 tendency to sterility which belongs to nearly allied species 
 in a state of nature. As bearing on this subject, Mr. Darwin 
 observes that there are many animals which, when tamed or 
 subjugated to man, refuse to breed in captivity although 
 they enjoy perfect health, as the tiger, for example, in India, 
 and parrots in Europe, and the elephant except when allowed, 
 as in Assam, to range in a half-wild state in the woods ; a fact 
 showing how easily sterility may be superinduced when habits 
 long fixed, as well as many of the conditions of existence in 
 a wild state, are interfered with. But those species which 
 more readily accommodate themselves to new circumstances 
 arising out of their association with man, and which can be 
 carried by him to all climates, exhibit the same plasticity of 
 character in reference to the reproductive organs. 
 
 It cannot, however, be pretended that a satisfactory expla- 
 nation can be offered of the tendency of domestication to in- 
 crease the prolificness of animals and plants. In reference to 
 the opposite effect of a return to the wild state, the following 
 fact is worthy of mention. About the year 1419 some rabbits 
 were introduced into the island of Porto Santo, where they 
 multiplied exceedingly, and have flourished ever since in a 
 feral state. In many of their characters they constitute a 
 marked race, which is smaller than the original parent stock. 
 When two of the males were brought to the London Zoologi- 
 cal Gardens, they refused to pair with any varieties of domes- 
 tic rabbits, isolation for many generations under peculiar 
 geographical conditions having apparently superinduced an 
 aversion to cross even with such nearly allied races. 
 
 If two wild species, such as the wolf and the jackal, can by 
 the intervention of man be made to breed together and the 
 offspring proves fertile, such a result must shake our faith 
 in the theory that species have been specially endowed with 
 mutual sterility in order to keep them distinct. It is certainly 
 very strange that when domesticated races have been made 
 to differ to such an extent that if wild they would have been 
 referred by naturalists to different genera, there should still 
 be scarcely any well-attested examples even of an approach 
 to sterility in their mongrel offspring. It is all the more 
 
314 VARIATION OF PLANTS AND ANIMALS. [On. XXXVI. 
 
 strange if we are persuaded of the truth of Mr. Darwin's 
 view, that the whole organisation of an animal is so tied to- 
 gether, that when even slight variations occur in any one part 
 other parts usually become modified. 
 
 Among many other illustrations which he gives of this 
 principle, called by him in the ' Origin of Species ' ' correlation 
 of growth,' and in his last work i correlated variability,' he 
 mentions that pigeons with feathered feet have skin between 
 their outer toes, pigeons with short beaks have small feet, and 
 those with ]ong beaks large feet ; and some instances of corre- 
 lation, he remarks, are quite whimsical : thus, cats which are 
 entirely white and have blue eyes are generally deaf. One 
 case is recorded where the blue iris at the end of four months 
 began to grow dark-coloured, and then the cat began to 
 hear.* 
 
 If the sterility of the mule offspring be due, as the same 
 naturalist suggests, to the imperfection of their reproductive 
 organs arising from the blending together of two different 
 structures and constitutions, which causes a disturbance and 
 interferes with the development of the embryo, we might 
 have expected that differences affecting permanently not 
 only the external form and shape, but even the shape of the 
 skull in many vertebrate animals, as well as their instincts 
 and habits, would have been accompanied, when such fixed 
 varieties were crossed, with a disturbance in the reproductive 
 organs and consequent sterility in the hybrids. 
 
 At the same time we must remember that the greatest 
 changes in races have been brought about by selection, and 
 it has never been the object of man to modify the reproduc- 
 tive organs with a view of producing two races mutually 
 sterile, nor if he wished to make such an experiment, would 
 he know in what manner to proceed. Moreover, we have 
 seen how possible it is to alter the foliage of plants without 
 their seeds varying, or to change their seeds, fruit, or flowers 
 without the character of the root or leaves being affected. 
 It is in fact established, in spite of 4 correlation,' that we may 
 cause some organs to be greatly modified, while another 
 to which we have not directed our attention may continue 
 
 * Dr. Sichet, cited by Darwin ' On Variation,' p. 329. 
 
CH. XXXVI.] CORRELATION OF GROWTH. 315 
 
 almost or entirely unaltered. In the next chapter, when we 
 treat of Natural Selection, we shall have again to consider 
 in what way the varieties of wild species may be supposed 
 to have departed so far in. the course of ages from the parent 
 stock and from each other as to be incapable of being crossed, 
 notwithstanding the fact which seems directly opposed to 
 such a result, that a slight amount of variation in indi- 
 viduals of the same species when they are intermarried in- 
 fuses fresh uigour and increased fertility into the offspring. 
 
316 
 
 CHAPTER XXXVII. 
 
 NATUEAL SELECTION. 
 
 NATURAL AS COMPARED TO ARTIFICIAL SELECTION TENDENCY IN EACH 
 SPECIES TO MULTIPLY BEYOND THE MEANS OF SUBSISTENCE TERMS ' SELEC- 
 TION' AND 'SURVIVAL OF THE FITTEST' GREAT NUMBER AND VARIETY OF 
 
 THE NATURAL CONDITIONS OF EXISTENCE ON WHICH THE CONSTANCY OR 
 
 VARIATION OF A SPECIES DEPENDS ACCLIMATISATION OF SPECIES THE 
 
 INTERCROSSING OF SLIGHT VARIETIES BENEFICIAL BREEDING IN AND IN 
 
 INJURIOUS "WILD HYBRID PLANTS, AND OPINIONS OF LINNAEUS ON PROTEAN 
 GENERA DE CANDOLLE ON WILD HYBRIDS HYBRIDITY WILL NOT ACCOUNT 
 FOR SPECIAL INSTINCTS THE SPECIES OF POLYMORPHOUS GENERA MORE 
 
 VARIABLE AND COMPARATIVELY MODERN ALTERNATE GENERATION DOES 
 
 NOT EXPLAIN THE ORIGIN OF NEW SPECIES. 
 
 NATURAL AS COMPARED TO ARTIFICIAL SELECTION. In 
 the last chapter we have spoken of the great changes which 
 man has brought about in the course of many generations 
 in the form and characters of animals and plants, by selecting 
 certain useful varieties of a species, and breeding from them 
 to the exclusion of other varieties less profitable or pleasing 
 to him. In this way he has gone on accumulating differ- 
 ences in successive generations until new races have been 
 formed as distinct in outward shape, and sometimes in the 
 internal structure of important organs, as are most of the 
 species which we meet with in nature ; the races, however, 
 thus artificially produced being distinguishable from wild spe- 
 cies by the fertility of the offspring produced by their union. 
 We may next consider the modification of species effected 
 by variation and what Mr. Darwin has called e natural selec- 
 tion,' of which we gave a brief analysis in Chap. XXXV. 
 How far do the breeder, the agriculturist, and gardener, 
 when they form new races, simply imitate a process by which, 
 in a much greater lapse of time, nature causes still more 
 important deviations from the original type ? 
 
CH. XXXVII.] EAPID INCREASE OF ANIMALS. 317 
 
 Of the laws which may govern the variety-making power 
 we are, as Mr. Darwin admits, profoundly ignorant ; and if, 
 as seems probable, these laws embrace the principle of pro- 
 gressive development explained in the first volume (Chap. 
 IX.), they must be of so high and transcendental a nature 
 that we may well despair of ever gaining more than a dim 
 insight into them. But granting what is undeniable, that 
 there is a tendency in all animals and plants to possess 
 individual peculiarities by which they differ slightly from 
 their parents and from each other, are there not forces in 
 operation in the organic and inorganic world, which, in the 
 course of thousands or millions of generations, may cause new 
 races, varying more and more in a particular direction, until 
 at length they constitute new species ? If there be such a 
 process in nature, it will most nearly resemble that kind of 
 human selection which has been called ' unconscious,' and 
 which for reasons explained in the last chapter is even more 
 effective in the long run than that which is intentional. 
 
 Tendency in each species to multiply beyond the means of 
 subsistence. It has already been stated that if all the progeny 
 of each animal and plant which are born into the world were 
 allowed to come to maturity, a single species would soon fill 
 the whole of the habitable land or water. Malthus long ago 
 pointed out, that in the case of man, if his capability of in- 
 crease were not checked by scarcity of food, the earth would 
 soon fail to afford standing room for the descendants of a single 
 pair. The elephant, says Darwin, although reckoned the 
 slowest breeder of all known animals, would nevertheless so 
 multiply, if we assume that it only begins to have young when 
 thirty years old, and brings forth three pair between that age 
 and the age of ninety, that if all its descendants were to live 
 out the term of their natural life, at the end of five centuries 
 there would be fifteen million elephants descended from a 
 single pair. 
 
 In the severe struggle for existence which is always going 
 on, those varieties or species which have any even the slight- 
 est advantage over others inhabiting the same district will be 
 the survivors. They may be able to bear a degree of cold or 
 heat, moisture or dryness, which others cannot endure ; they 
 
318 NATUEAL SELECTION. [On. XXXVII. 
 
 may have strength or agility to escape foes to which others 
 must fall victims ; but the great trial, as before hinted, con- 
 sists in the capacity of maintaining their ground at that 
 season of the year when food is scarcest. 
 
 Term ' Natural Selection ' or ' Survival of the fittest. 9 Mr. 
 Herbert Spencer has proposed to substitute for ( Natural Selec- 
 tion ' the term c Survival of the fittest ;'* an expression which 
 is often very appropriate, and which some naturalists prefer, 
 because the various causes which in the natural world enable 
 one variety or race to prevail over another, act according 
 to fixed laws, and do not imply a conscious choice like the 
 selection of the breeder. But the metaphor employed by 
 Darwin appears to me legitimate and often useful, as remind- 
 ing us of the close analogy which exists between the manner 
 in which new races are formed by man and the way in which 
 it is supposed by Darwin and Wallace that they are slowly 
 produced by nature. Professor Huxley in his comments on 
 this subject observes, that the winds and waves of the Bay of 
 Biscay in the district called the Landes near Bordeaux have 
 spread out over a wide area great heaps of sand all the grain 
 of which are below a certain size. These grains have been 
 separated from the larger gravel with as much precision as 
 if by the aid of a sieve. That which the wind and the sea 
 are to a sandy beach the sum of all the influences which we 
 term the conditions of existence is to living organisms. The 
 weak are sifted out from the strong. A frosty night selects 
 the hardy plants in a plantation from among the tender ones 
 as effectually as if the intelligence of a gardener had been 
 operative in cutting the weaker organisms down.f 
 
 Number of conditions on which the constancy or the variation 
 of a species depends. If the reader will reflect on the changes 
 in the earth's physical geography and climate which were 
 alluded to in the first volume (Chapters XI. and XII.), as 
 having occurred in the course of geological periods, he will 
 not fail to perceive that the new conditions to which plants 
 and animals inhabiting any given province must be exposed 
 will be far more important in the aggregate than the change 
 
 * Principles of Biology, p. 444. 
 
 f Nat. Hist. Kev. 'On Origin of Species,' p. 578. 
 
CH. XXXVII.] CONDITIONS OF EXISTENCE. 319 
 
 of circumstances to which man can in a few thousand years 
 subject any animal or plant under domestication. 
 
 Were we to attempt to enumerate all the conditions which 
 Mr. Herbert Spencer has concisely termed the c environment ' 
 of a species, they would be almost endless. They would com- 
 prise not only the mean temperature of the air or water, but 
 the extreme heat or cold in the different seasons of the year, 
 the quantity and intensity of sunshine at different periods, 
 the number of clear and of rainy days, the quantity of ice and 
 snow, the direction and strength of the wind, the pressure 
 of the atmosphere and its electrical state, the nature of the soil, 
 its elevation* above the sea, the habits, instincts, and properties 
 of hundreds of contemporary animals and plants, some of them 
 friendly others inimical, the comparative abundance or rarity 
 of those species on which the food of a given animal or plant 
 may depend, circumstances, many of them, wholly beyond 
 the control of the breeder or horticulturist. All of them, 
 moreover, are brought into play by natural selection with a 
 uniformity and persistency which man cannot emulate. 
 
 Dr. Hooker ascertained that the average range in vertical 
 height of flowering plants in the Himalayan mountains 
 amounted to 4,000 feet, and the upper and lower limits 
 of some species are even distant from each other as much 
 as 8,000 feet. If we transplant individuals which inhabit 
 the higher limits in these mountains into our British 
 gardens, we find that they are hardier, and better able to 
 stand the cooler climate of England, than those taken from 
 the inferior or warmer stations. This acclimatisation has 
 been the result of natural selection during thousands of gene- 
 rations. The physiological constitution of the plant has 
 been acted upon, and a hardy race established, although 
 the change may not have been sufficient to cause it to rank 
 as more than a variety. It may sometimes be more dwarfed 
 in size than individuals of the same species living in the 
 moist and hotter region far below. It may perhaps varv 
 slightly in the colour of its flowers, and, if deciduous, in 
 the period of shedding its leaves or in its general habits 
 of growth. Yet its characters may not be on the whole 
 sufficiently distinct to induce the botanist to rank it as 
 
320 NATURAL SELECTION. [Cn. XXXVII 
 
 more than what is called a geographical variety. In arriving 
 at such an opinion he may perhaps be chiefly guided by 
 his ability to trace in the individuals inhabiting all the 
 intermediate heights a gradual passage from one extreme 
 of the series to another. 
 
 Intercrossing of slight varieties beneficial. It would be 
 an interesting experiment, and one which has not yet been 
 made, to cross individuals taken from the lowest station with 
 those hardier races which have been formed by acclimatisa- 
 tion in the upper regions of the mountain, and ascertain 
 whether they would produce as much seed as individuals 
 fertilised by the pollen of plants of the same station. If 
 there were any signs of comparative sterility in such crosses, 
 it would afford an indication of the commencement under 
 nature of that character which distinguishes wild species 
 from artificially formed races. There is good reason, how- 
 ever, to believe that before any difficulty of crossing, or any 
 deficiency of prolific power in the offspring, would be appa- 
 rent, the races must depart so widely from each other that 
 their distinctness as species would already be a debateable 
 question with the naturalist. And this brings us to the 
 principal obstacle which we encounter when we endeavour to 
 refer the gradual formation of a new species to variation 
 and natural selection. If some degree of sterility was found 
 in the offspring of slight varieties, and this want of prolific 
 power went on augmenting in proportion as the deviation from 
 a common stock became more and more marked, the fact that 
 closely allied species inhabiting the same region keep distinct 
 would be intelligible. But the phenomena are precisely the 
 reverse. Instead of any reluctance being exhibited by slight 
 variations to intermarry and propagate their kind, their in- 
 termixture, on the contrary, takes place freely and infuses 
 fresh vigour and fertility into the species. Individuals of 
 the normal type are always the most numerous, and slight 
 varieties are usually soon merged in the general average, so 
 that the new characters disappear. In some cases where 
 the races are so wide apart as to be thought by some 
 to belong to distinct species, it is only necessary to cross 
 their mongrel or hybrid offspring with pure individuals 
 
CH. XXXVII. ] BREEDING IN AND IN INJURIOUS. 321 
 
 of one of the two parent stocks for six or sometimes eight 
 generations in succession, and every trace of the foreign ad- 
 mixture will be lost. The mutual absorption in this manner 
 of the European and negro races the one into the other, by 
 a certain number of intermarriages with one of the two stocks, 
 has been frequently verified. The efficacy of the principle 
 above adverted to, in causing species to breed true for ages, 
 and checking lawless divergence, in spite of the numerous 
 varieties which occur in every generation, is obvious ; the 
 only difficulty is to conceive how, if there be such proneness 
 in each aberrant form to merge into the normal type, a new 
 and permanent species can ever be established. It would 
 seem to require prolonged isolation under altered conditions, 
 such as may occur in diiferent parts of the same continent, or 
 still more frequently in different islands of the same archi- 
 pelago. But we have yet to learn what degree of divergence 
 must be attained in two races sprung from the same stock 
 before a decided disinclination to breed together will arise, 
 and how much farther this must be carried before the off- 
 spring of the cross, if produced, will be sterile. 
 
 Breeding in and in injurious. It has already been stated 
 that certain domestic races prefer breeding with their own 
 kind ; on the other hand, it is well ascertained that too much 
 breeding in and in has an injurious effect. 
 
 The half- wild cattle which have been kept for four or five 
 centuries or more in British parks, as in those of Lord 
 Tankerville and the Duke of Hamilton, where the total 
 number varies from sixty to eighty, are relatively far less 
 fertile than the enormous herds of half-wild cattle in South 
 America. But even in the latter case it is believed that the 
 occasional introduction of animals from distant localities is 
 necessary to prevent degeneration in size and fertility.* 
 The decrease in bulk from ancient times of the British cattle 
 alluded to must, says Darwin, have been prodigious, as ac- 
 cording to Eiitimeyer they are the descendants of the gigantic 
 Bos primigenius. The Chillingham cattle are white, but 
 this is partly due to selection, as dark-coloured calves are 
 
 * Darwin ' On Variation,' chap, xvii., who cites Azara. 
 VOL. II. Y 
 
322 NATUBAL SELECTION. [On. XXXVII. 
 
 occasionally destroyed. In the Pampas in Texas, or in 
 Africa, where cattle have run wild in large herds, they have 
 acquired a nearly uniform dark-brownish red.* A breed 
 called Niatas, seen by Darwin on the banks of the Plata, 
 has a short and broad forehead and other peculiarities in the 
 shape of the skull and in the projection and curvature of 
 the lower jaw. In this variety scarcely a single bone agrees 
 exactly in shape with that of the common ox. This breed, 
 which has existed for at least a century, is a good illustration 
 of the manner in which a marked variety may be formed in 
 a nearly wild state, and of the tendency of such a new race, 
 when brought into contact with other breeds, to keep distinct. 
 Such a tendency may point to the manner in which, in the 
 course of many generations, if man did not interfere, a greater 
 divergence from a common original and a more decided 
 aversion to sexual union might be superinduced. If the lapse 
 of time necessary for such transformations be very great, the 
 extinction of intermediate races will take place, by which a 
 new bar to the commingling of the nearest allied types will 
 be raised. 
 
 In speculating on this subject, Mr. Darwin reminds us 
 that a slight change in the conditions of life is found to be 
 very generally advantageous to cultivated animals and plants, 
 although we know that great changes are injurious. So, in 
 the case of man, the invalid whose constitution will be 
 benefited by going from England to the South of France or 
 Madeira, may perish if transferred to Fernando Po. We 
 may easily imagine, that, although the crossing of most of 
 the varieties of cultivated plants and animals imparts strength 
 and fertility to them, yet under nature, and in the course of 
 ages, the variation may be carried so far as to modify the 
 reproductive organs, and render the formation of a fertile 
 hybrid germ impossible. f 
 
 The refusal of many tamed animals to breed in captivity, 
 has been alluded to, and it demonstrates the susceptibility of 
 the reproductive system to be affected by a change in the 
 
 * Azara and others, cited by Darwin f Darwin ' On Variation,' chap. 
 
 ' On Variation,' p. 86. xviii. 
 
CH. XXXVII.] LIXX.EUS ON PROTEAN GENERA. 323 
 
 natural conditions of life. That changes greater in degree or 
 even equal, but continuing uniformly in force for many thou- 
 sands of generations, should bring about the mutual sterility 
 of two allied races or species, is quite conceivable. 
 
 If this point of divergence had been reached by the breeder 
 or horticulturist, the derivability of a new species by gradual 
 deviation from an old type would almost have ceased to be a 
 debateable question in natural history. 
 
 Allusion has been made to the extinction of intermediate 
 varieties. This would happen the more readily on the prin- 
 ciple well pointed out by Darwin, that in order that a given 
 area should support the greatest number of individuals, these 
 ought to belong to a great many widely dissimilar types ; and 
 what is true of genera, must sometimes be true of the races 
 of a species. There may be room for those which represent 
 the extreme terms of a series, and no equally advantageous 
 place for those of intermediate characters. 
 
 Wild hybrid plants, and opinions of Linnaeus onprotean genera. 
 If wild species were not averse to intermarry, or if their 
 hybrid offspring were not almost always sterile, it is obvious 
 that in a few generations there would be a blending together 
 of all existing types, and we should behold everywhere that 
 state of confusion which we now only meet with in certain 
 exceptional cases. 
 
 To the occasional occurrence of protean or polymorphous 
 genera, as they have sometimes been called, where a great 
 number of closely allied species occur, Linnaeus makes 
 frequent allusion in his writings. He was evidently unable 
 to reconcile the phenomena with his dogma of the immu- 
 tability of primordially created species. In an address to 
 the University of Upsala in 1751,* he gave a list of nearly 
 thirty ' prolific ' genera of plants, in which the species 
 were of doubtful or suspicious value ; enumerating, among 
 others, the willows and saxifrages in Europe, the oaks and 
 asters in North America, the cactuses in South America, the 
 heaths and everlastings at the Cape ; in each of which there 
 were so many intermediate gradations between what are 
 
 * Linnaeus, 'Pluntse Hybridre,' 32nd Dissertation of the Amcenitates Academics, 
 vol. iii. pp. 28-62. 
 
 Y 2 
 
324 NATURAL SELECTION, [On. XXXVII. 
 
 commonly called allied species, as to make their origin a 
 curious subject of enquiry. He considered how far hybri- 
 disation could explain the enigma, and having his new dis- 
 covery of the sexuality of plants uppermost in his mind, he 
 was disposed to exaggerate the extent to which that cause 
 might have been efficacious in originating new forms. Hy- 
 brids, he says, are not always sterile, and not only species, but 
 even genera, may have arisen from this source.*" But in a 
 great many instances, when he speaks of one species being 
 derived from an older one, and when he calls allied species, 
 which inhabit distant countries, c sisters,' as being of common 
 origin, and when he remarks of several forms that they had 
 their first origin from one and the same source, he is evidently 
 speculating on the origin of species by variation. In this 
 spirit he avowedly groups many forms of Ophrys, Valerianella, 
 Myosotis, MedicagOy and other genera under single collective 
 specific names, because, he says, after a comparison of a great 
 number of them, all the forms will be seen to have had their 
 origin from one source. He even throws out the idea 
 that the day may come when botanists may hold that all 
 the species of the same genus may have sprung from the same 
 mother, f 
 
 The occurrence of some hybrids in a state of nature is 
 admitted by all botanists, although they are rare. Centaurea 
 hybrida is produced, according to Herbert, by the frequent 
 intermixture of two well-known species of Centaurea ; but this 
 hybrid race never seeds. Ranunculus lacerus, also sterile, has 
 been produced accidentally at Grenoble, and near Paris, by 
 the union of two ranunculi; but this occurred in gardens. J 
 Mr. Darwin has lately (in the summer of 1867) satisfied him- 
 self by experiment that the common oxlip is a natural hybrid 
 between the primrose and cowslip, and these two last he 
 considers to be distinct species. Mr. Herbert, in one of his 
 
 * 'Novas species, immo et genera ex and Love"n, have kindly pointed out to 
 
 copula diversarum specierum in Kegno me these and many other passages in 
 
 Vegetabili oriri,' etc. Amcen. Academ. which Linnaeus shows that he had freely 
 
 orig. ed. 1744, ed.Holm. 1749, vol. i. p. 70. speculated on the variability and trans- 
 
 f ' Tot species dici congeneres quot mutation of species, 
 
 eadem matre sint progenitse.' -Amceni- j Hon. and Eev. W. Herbert, Hort. 
 
 tatesAcademicse, vol. vi. p. 12. Twoemi- Trans., vol. iv. p. 41. 
 nent Swedish naturalists, Professors Fries 
 
CH. XXXVII.] DE CANDOLLFS OPINIONS. 325 
 
 ingenious papers on mule plants, endeavours to account for 
 their rare occurrence in a state of nature, from the circum- 
 stance that all the combinations that were likely to occur 
 have already been made many centuries ago; but in our 
 gardens, he says, whenever species, having a certain degree 
 of affinity to each other, are transported from different coun- 
 tries, and brought for the first time into contact, they give 
 rise to hybrid species.* 
 
 De Candolle's opinions. Auguste De Candolle, in his Essay 
 on Botanical Geography, published in 1820, observes, that 
 the varieties of plants range themselves under two general 
 heads : those produced by external circumstances, and those 
 formed by l^bridity. After adducing various arguments to 
 show that neither of these causes can explain the permanent 
 diversity of plants indigenous in different regions, he says, in 
 regard to the crossing of races, ' I can perfectly comprehend, 
 without altogether' sharing the opinion, that, where many 
 species of the same genera occur near together, hybrid species 
 may be formed, and I am aware that the great number of 
 species of certain genera which are found in particular regions 
 may be explained in this manner; but I am unable to conceive 
 how anyone can regard the same explanation as applicable to 
 species which live naturally at great distances. If the three 
 larches, for example, now known in the world, lived in the 
 same localities, I might then believe that one of them was the 
 produce of the crossing of the two others ; but I never could 
 admit that the Siberian species has been produced by the 
 crossing of those of Europe and America. I see, then, that 
 there exist, in organised beings, permanent differences which 
 cannot be referred to any one of the actual causes of varia- 
 tion, and these differences are what constitute species.' f In 
 this passage De Candolle assumes that the actual causes of 
 
 Jr o 
 
 variation have their strict and definite limits ; an hypothesis 
 which the advocates of transmutation say, and not without 
 reason, is quite as arbitrary as the opposite or rival assump- 
 tion of indefinite modifiability. 
 
 Hybridity will not account for special instincts. As to the 
 
 * Hon. and Rer. W. Herbert, Hort. Trans., vol. iv. p. 41. 
 t Essai Elementaire, &c. 3ieme partie. 
 
32 G NATURAL SELECTION. [Cn. XXXVII. 
 
 derivation of species in general from the mixture of a limited 
 number of original stocks, differing widely from each other, 
 all our experience is against such an hypothesis ; for between 
 plants or animals of very distinct genera we can obtain 
 no cross-breeds. Nor is it easy to comprehend how species 
 of intermediate character between two divergent types could 
 give rise to a mongrel offspring having qualities and instincts 
 fitting them to hold their ground in the struggle for life. 
 
 If we take some genus of insects, such as the bee, we find 
 that each of the numerous species has some difference in its 
 habits, its mode of collecting honey, or constructing its 
 dwelling, or providing for its young, and other particulars. 
 In the case of the common hive bee, the workers are described, 
 by Kirby and Spence, as being endowed with no less than 
 thirty distinct instincts.* So also we find that, amongst a 
 most numerous class of spiders, there are nearly as many 
 different modes of spinning their webs as there are species. 
 When we recollect how complicated are the relations of 
 these instincts with co-existing species, both of the animal 
 and vegetable kingdoms, it is scarcely possible to imagine 
 that a bastard race could spring from the union of these 
 species, and retain just so much of the qualities of each 
 parent stock as to preserve its ground in spite of the dangers 
 which surround it. 
 
 The theory of the origin of species by variation and natural 
 selection, would be untenable unless we could assign very 
 different degrees of antiquity to the generic and specific 
 types now existing. Some of them must date from remote 
 geological periods, others must be comparatively modern. 
 Of this last class are those forms of which the living re- 
 presentatives run so much the one into the other that 
 scarcely any two naturalists can agree as to where the lines 
 "of demarcation between the species ought to be drawn. 
 The British roses present a familiar illustration of this 
 ambiguous state of things, Mr. Bentham making only five 
 species of them, and Dr. Babington seventeen. Mr. Darwin 
 sees in this abundance of closely allied species an active 
 
 * Intr. to Entom. vol. ii. p. 504, ed. 1817. 
 
CH. XXXVII.] ALTERNATE GENERATION. 327 
 
 manufacture of new races, and a want of time since their 
 origin to bring about the extinction of the varieties which 
 still link together the divergent members of the series, and 
 he remarks that the species of these polymorphous genera 
 are unusually variable. When the reader has reflected 
 on what will be said in Chapter XLII. on the extinction 
 of species, he will understand why, as a general rule, there 
 are so many missing links, and why ' protean ' genera are 
 the exception. No clue to this enigma is afforded by the 
 hypothesis of special creation. On the other hand, if it had 
 been found that fertile hybrids could spring from animals 
 and plants which are remote in their organisation, the oc- 
 currence of protean genera might certainly be explained ; but 
 in that case they ought to have been universal, and the 
 present condition of the animal and vegetable world would 
 then be a greater mystery than ever. 
 
 Alternate generation. The discovery in certain classes of 
 invertebrate animals of what has been called i alternate 
 generation,' has suggested to some zoologists a possible 
 mode by which nature may usher abruptly into the world 
 not only new organisms but even types of being of a higher 
 grade than any which pre-existed in the same class. Certain 
 sertularian polyps give birth to other polyps like themselves, 
 and these again produce other individuals of the same form 
 and structure, and this may continue for many generations 
 till at last one of the series gives birth to a more highly 
 organised creature called a Medusa. Formerly naturalists 
 regarded this Medusa as belonging to a distinct genus or 
 even family, of decidedly higher or more complex organi- 
 sation than the Sertularise. If then it is said, under a 
 change of conditions the Sertularia and the Medusa should 
 each of them go on for an indefinite number of generations 
 producing, according to the more ordinary rules of inherit- 
 ance, offspring like themselves, we should have an example of 
 the coming into existence of a new and higher form without 
 the disappearance of the lower one from which it had been 
 evolved ; but, unfortunately for such speculations, nothing 
 of the kind has ever been witnessed. The Sertularia, although 
 it is hatched from an egg, never produces one, but simply 
 
328 NATURAL SELECTION. [On. XXXVII. 
 
 gives birth to other polyps by what is termed internal 
 gemmation, and when at length the male and female Medusse, 
 after sexual union, produce eggs from which the Sertu- 
 larise are born, the whole cycle of changes returns into 
 itself, just as do the metamorphoses of an insect. The same 
 may be said of certain aphides which, coming from an 
 egg, give birth by gemmation to a sexual offspring, and these 
 again to others like themselves, till at length some of their 
 descendants produce perfect and winged males and females, 
 from whose union eggs proceed, and then the cycle of trans- 
 formation recommences. 
 
 Even if there had been any indication of the Sertularia 
 and Medusa becoming each of them independent of the 
 other, this phenomenon would not afford an illustration of 
 what is usually meant by special creation, as the new form 
 would still be evolved out of the older one by descent. In 
 truth there are only as yet two rival hypotheses, between 
 which we have our choice in regard to the origin of species 
 namely, first, that of special creation and, secondly, that of 
 creation by variation and natural selection. In the next 
 four chapters I shall treat of the light thrown by the geo- 
 graphical distribution of animals and plants on the claims 
 of these two rival hypotheses to our acceptance. 
 
329 
 
 CHAPTEE XXXVIII. 
 
 ON THE GEOGRAPHICAL DISTRIBUTION OF SPECIES. 
 
 GEOGRAPHICAL DISTRIBUTION OF ANIMALS BUFFON ON SPECIFIC DISTINCT- 
 NESS OF QUADRUPEDS OF THE OLD AND NEW WORLDS DOCTRINE OF 'NATURAL 
 BARRIERS ' AUSTRALIAN MARSUPIALS GEOGRAPHICAL RELATION OF EXTINCT 
 
 FOSSIL FORMS TO THEIR NEAREST ALLIED LIVING GENERA AND SPECIES 
 
 GEOGRAPHICAL PROVINCES OF BIRDS ACCORDING TO DR. SCLATER THEIR 
 
 APPLICABILITY TO ANIMALS AND PLANTS GENERALLY NEOTROPICAL REGION 
 
 NEARCTIC PAL^E ARCTIC ETHIOPIAN INDIAN AUSTRALIAN WALLACE ON 
 
 THE LIMITS OF THE INDIAN AND AUSTRALIAN REGIONS IN THE MALAY ARCHI- 
 PELAGO. 
 
 GEOGRAPHICAL DISTRIBUTION OF ANIMALS. Although in 
 speculating on 'philosophical possibilities,' said Buffon, 
 writing in 1 755, ' the same temperature might have been ex- 
 pected, all other circumstances being equal, to produce the 
 same beings in different parts of the globe, both in the 
 animal and vegetable kingdoms, yet it is an undoubted fact, 
 that when America was discovered, its indigenous quadrupeds 
 were all dissimilar to those previously known in the Old 
 World. The elephant, the rhinoceros, the hippopotamus, 
 the camelopard, the camel, the dromedary, the buffalo, the 
 horse, the ass, the lion, the tiger, ,the apes, the baboons, and 
 a number of other mammalia, were nowhere to be met with 
 on the new continent ; while in the old, the American species, 
 of the same great class, were nowhere to be seen the tapir, 
 the lama, the pecari, the jaguar, the couguar, the agouti, the 
 paca, the coati, and the sloth.' 
 
 These phenomena, although few in number relatively to 
 the whole animate creation, were so striking and so positive 
 in their nature, that the great French naturalist caught sight 
 at once of a general law in the geographical distribution of 
 organic beings, namely, the limitation of groups of distinct 
 species to regions separated from the rest of the globe by 
 certain natural barriers. It was, therefore, in a truly philo- 
 
330 GEOGEAPHICAL DISTRIBUTION OF SPECIES. [Cn. XXXVIII. 
 
 sophical spirit that, relying on the clearness of the evidence 
 obtained respecting the larger quadrupeds, he ventured to 
 call in question the identifications announced by some con- 
 temporary naturalists of species of animals said to be common 
 to the southern extremities of America and Africa."* 
 
 In order to appreciate the importance and novelty of the 
 doctrine, that separate areas of land and water were the abodes 
 of distinct species of animals and plants, we must look back 
 to the times of Buffon and see in what crude conjectures 
 even so great a naturalist as his illustrious contemporary 
 Linnaeus indulged, when speculating on the manner in which 
 the earth may first have become peopled with its present in- 
 habitants. The habitable world was imagined by the Swedish 
 philosopher to have been for a certain time limited to one 
 small tract, the only portion of the earth's surface that was 
 as yet laid bare by the subsidence of the primaeval ocean. 
 In this fertile spot the originals of ah 1 the species of plants 
 which exist on this globe were congregated together with 
 the first ancestors of all animals and of the human race. 
 ' In qua commode habitaverint animalia omnia, et vegetabilia 
 Isete germinaverint.' In order to accommodate the various 
 habits of so many creatures, and to provide a diversity of 
 climate suited to their several natures, the tract in which the 
 creation took place was supposed to have been situated in 
 some warm region of the earth, but to have contained a lofty 
 mountain range, on the heights and in the declivities of 
 which were to be found all temperatures and every climate, 
 from that of the torrid to that of the frozen zone.f There 
 are still perhaps some geologists who adhere to a notion once 
 very popular, that there are signs of a universal ocean at a 
 remote period after the planet had become the abode of 
 living creatures. But few will now deny that the proportion 
 of sea and land approached very nearly to that now estab- 
 lished long before the present species of plants and animals 
 had come into being. 
 
 The reader must bear in mind that the language of Buffon, 
 
 * Buffon, vol. v. 1755. On the Vir- also Prichard, Phys. Hist, of Mankind, 
 ginian Opossum. vol. i. p. 17, where the hypotheses of 
 
 f 'De terra habitabili increment ; ' different naturalists are enumerated. 
 
CH. XXXVIII.] THE DOCTKINE OF SPECIFIC CENTBES.' 331 
 
 iii 1755, respecting ' natural barriers' which has since been 
 so popular, would be wholly without meaning had not the 
 geographical distribution of organic beings led naturalists 
 to adopt very generally the doctrine of specific centres, or, in 
 other words, to believe that each species, whether of plant or 
 animal, originated in a single birthplace. Reject this view, 
 and the fact that not a single native quadruped is common 
 to Australia, the Cape of Good Hope, and South America, 
 can in no ways be explained by adverting to the wide extent 
 of intervening ocean, or to the sterile deserts, or the great 
 heat or cold of the climates, through which each specie's 
 must have passed, before it could migrate from one of those 
 distant regions to another. It might fairly be asked of 
 one who talked of impassable barriers, why the same kan- 
 garoos, rhinoceroses, or lamas, should not have been created 
 simultaneously in Australia, Africa, and South America? 
 The horse, the ox, and the dog, although foreign to these 
 countries until introduced by man, are now able to support 
 themselves there in a wild state ; and we can scarcely doubt 
 that many of the quadrupeds at present peculiar to Australia, 
 Africa, and South America, might have continued in like 
 manner to inhabit all the three continents, had they been in- 
 digenous in each, or could they once have got a footing there 
 as new colonists. 
 
 We have seen in the passage already cited that Buffon 
 called attention to the fact that the apes and baboons of the 
 Old World were nowhere to be found in America. Now that 
 so many new forms of quadrumana have been brought to 
 light in both continents, the want of agreement in the ana- 
 tomical and many other characters of the two groups has 
 been rendered even still more prominent. 
 
 The Old- World apes .and monkeys have been called Catar- 
 rhini because they have a narrow division between the nos- 
 trils ; those of the New World, Platyrrhini because their 
 nostrils are widely separated. In the Catarrhine division 
 the number of teeth, not only in the Orangs and Gibbons 
 which approach nearest to the human race in form and 
 structure, but in all the other quadrumana with the exception 
 of one or two aberrant groups such as the Lemurs, are 32, as 
 
332 GEOGRAPHICAL DISTRIBUTION OF SPECIES. [Cn. XXXVIII. 
 
 in man, whereas in all the Platyrrhine monkeys they are 
 36, for they have four additional false molars. This marked 
 distinctness in their dentition is accompanied by many other 
 differences ; such as the prehensile tails belonging exclusively 
 to so many of the American monkeys, and the cheek-pouches 
 peculiar to the Old- World quadrumana. 
 
 Australian marsupials. The adherence to certain peculiar 
 types of structure observable in the animals inhabiting dis- 
 tinct geographical provinces was illustrated in a still more 
 striking manner, some time after the publication of Buffon's 
 great work, by the discovery in Australia of a group of mam- 
 malia so unlike those of the Old World as to be referable 
 even to a distinct sub-class called the Marsupial, of which 
 there was only one genus previously known on the globe, 
 namely, the Opossum (Didelphis) of America. Some of these 
 pouched animals, like the kangaroo, were herbivorous, others, 
 like the Tasmanian wolf (Thylacinus) carnivorous, and on the 
 whole they presented a parallel series in which were found 
 representatives of nearly all the grand divisions of the pla- 
 cental mammalia of the rest of the world. Mr. Waterhouse 
 has described about 140 species proper to the mainland of 
 Australia, and about 9 others inhabiting New Guinea and 
 some neighbouring islands of the Malay archipelago. 
 Among these, only one species, the flying opossum (Petaurus 
 ariel), is common to one of the islands and the continent. 
 
 Geographical relation of extinct fossil forms to the nearest 
 allied living genera and species. When we speculate on the 
 meaning of this restriction of a peculiar division of the verte- 
 brata to a single province of the land, and try, by aid of it, to 
 gain some insight as to the plan which nature has followed in 
 peopling the earth with new species, we find ourselves in 
 some degree precluded from attributing the peculiarity of the 
 fauna to the nature of the climate, soil, and vegetation of 
 Australia. It has at least been ascertained experimentally 
 that when placental mammalia of various orders, whether 
 herbivorous or carnivorous such as the ox, the horse, the dog, 
 and the cat run wild in Australia, they are not only a match 
 for the native animals, but often obtain a mastery over them 
 and multiply greatly at their expense. How, then, does it 
 
CH. XXXVIIL] FOSSIL FORMS RELATED TO LIVING GENERA. 333 
 
 happen that the marsupials ever became dominant and 
 gained so complete an ascendancy over the placentals in the 
 struggle for life? The answer seems to be, that the more 
 highly organised placentals were never able td gain access to 
 Australia since it emerged from beneath the sea. It is cer- 
 tain that the marsupial fauna of that continent is of great 
 antiquity, for when we examine the bone-caves and super- 
 ficial alluvium of that part of the world, we find in them, as 
 in formations of corresponding age in Europe, the remains of 
 extinct quadrupeds ; but, instead of being referable to the 
 placental class, as in the Old World, the Australian fossils 
 consist of lost species of kangaroo, wombat, thylacine, and 
 other marsupials. One of these, the Diprotodon of Owen, 
 allied to the kangaroo, is of the size of a large rhinoceros ; 
 another, Nototlierium of Owen, not much inferior in bulk. 
 They are associated with extinct species of Dasyurus, besides 
 many of smaller dimensions, such as Phalangers and Potoroos. 
 In like manner, when we turn to the geological records of 
 South America, we find among the fossil remains of an age im- 
 mediately antecedent to the present, entombed in cavern and 
 alluvial deposits, the skeletons of Megatherium, Megalonyx, 
 Glyptodon, Mylodon, Toxodon, and Macrauchenia, extinct 
 forms generically allied to the existing sloth, armadillo, cavy, 
 capybara, and lama. In the caves also of Brazil we meet 
 with extinct monkeys associated with the above, and they are 
 referable to the genera Cebus and Callithrix, both belonging 
 to the Platyrrhine or New- World type of quadrumana before 
 mentioned. Thirdly, if we turn to the Europseo- Asiatic and 
 African province a region which comprises Europe, Asia, 
 and the north of Africa geology teaches us, in like manner, 
 that where the rein-deer, musk-ox, elephant, rhinoceros, 
 hippopotamus, horse, and many other Old- World types now 
 prevail, there also extinct species of the same genera abounded 
 formerly at a very modern geological period. In the pre- 
 sent state of science we cannot speak of the fossil quad- 
 rumana of the same great province, because the Pliocene 
 mammalia of tropical regions have as yet been so imperfectly 
 investigated, and it is only within the tropics that the ape 
 and monkey tribe is at present met with. But it is worthy 
 
334 GEOGRAPHICAL DISTRIBUTION OF SPECIES. [On. XXXVIII. 
 
 of notice that the extinct fossil monkeys which have been 
 discovered in Europe and India, all of them of Miocene age, 
 are referable to Old-World forms or to the Catarrhine division, 
 such as the Semnopithecus and the Gibbons. 
 
 Professor Owen and Mr. Darwin have dwelt emphatically 
 on this manifest relationship between the living and the dead 
 between peculiar genera and families of mammalia now in- 
 habiting certain parts of the world and the fossil representa- 
 tives of the same families found in corresponding regions.* 
 
 No hypothesis, therefore, respecting the origin of species will 
 be satisfactory unless it renders some account of the two 
 classes of phenomena already alluded to in this chapter. 
 First, species, and often genera and still larger groups, have 
 such a range in space as implies that they have spread in all 
 directions from a limited area called a ' centre of creation,' 
 until their progress was stopped by some natural barriers, 
 or conditions in the organic and inorganic world, hostile to 
 their farther extension. Secondly, the restriction of peculiar 
 generic forms to certain parts of the globe is not confined to 
 the present period, but may be traced back to an antecedent 
 geological epoch, when most of the species of mammalia were 
 different from those now living. The significance of this last- 
 mentioned fact can hardly be overrated. If we find Latin 
 inscriptions of ancient date most common in the country 
 where Italian is now spoken, Greek inscriptions most abundant 
 where they now talk modern Greek, and Egyptian hierogly- 
 phics inscribed on ancient monuments where for centuries 
 after the Christian era the kindred Coptic tongue was still in 
 use, we recognise at once that there is a geographical con- 
 nection between the three dead and the three living or 
 modern languages, which even if the entire intervening 
 history of those countries were lost, could not be questioned. 
 In this case it would afford a powerful argument in favour of 
 the derivative origin of the three modern languages, each of 
 them having a nearer relationship to the extinct tongues 
 than to any other lost forms of speech known to us by tradition 
 or history as having been used elsewhere on the globe. So the 
 
 * Owen, British Mammals and Birds; and Darwin, Journal of South America. 
 
CH. XXXVIII.] GEOGRAPHICAL PROVINCES OF ANIMALS. 335 
 
 intimate connection between the geographical distribution 
 of the fossil and recent forms of mammalia points to the 
 theory (without absolutely demonstrating its truth) that the 
 existing species of animals and plants, like the above-men- 
 tioned modern forms of speech, are of derivative origin and 
 not primordial or independent creations. 
 
 Geographical provinces of animals. It has been ascertained 
 that the sea as well as the land may be divided into what 
 have been called distinct provinces, each inhabited by certain 
 species of animals and plants, there being a considerable 
 coincidence in the range of species in the two grand 
 divisions of the organic world. The six principal regions 
 sketched out in 1857 by Dr. Sclater for birds (referring 
 rather to the genera and families in the class Aves than to 
 the species),* are applicable, with some slight exceptions, 
 to quadrupeds, reptiles, insects, and landshells, and to a 
 great extent even to plants. The regions alluded to are as 
 follows: 1. the Neotropical, comprising South America, 
 Mexico, and the West Indies. 2. The Nearctic, including 
 the rest of America. 3. The Palsearctic, composed of Europe, 
 Northern Asia as far as Japan, and Africa north of the 
 Sahara. 4. The Ethiopian, which contains the rest of Africa 
 and Madagascar. 5. The Indian, containing Southern Asia 
 and the western half of the Malay archipelago. 6. The 
 Australian, which comprises the eastern half of the Malay 
 islands, Australia, and most of the Pacific islands. 
 
 Neotropical region. To begin with the Neotropical, compre- 
 hending the West Indies and South America. The bird 
 fauna of this division is, according to Dr. Sclater, the richest 
 and most peculiar on the globe, and the mammalia are, as 
 Buffon remarked, singularly unlike those of the Old World. I 
 have already spoken of the Platyrrhine monkeys of South 
 America, as well as the sloths and armadilloes of that country, 
 and I might add the vampires or true blood-sucking bats 
 (Phyllostomidw), also the capybara, the largest of the rodents, 
 the carnivorous coati-mondi (Nasua), with a great many other 
 forms. 
 
 If there be any truth in the theory which refers the origin 
 
 ;; ' Paper read to Linnsfcan Society, Juue, 1857. 
 
336 GEOGEAPHICAL DISTRIBUTION OF SPECIES. [Cn. XXXVIII. 
 
 of species to variation or gradual transmutation, we should 
 expect that South America would contain a terrestrial fauna 
 very distinct from that of other lands ; for we are taught by 
 geology that the present continents and oceanic basins are 
 of very high antiquity,* and the southern part of the Ame- 
 rican continent is separated by a wide expanse of sea from 
 Africa, Asia, and the land of the Antarctic regions. We 
 cannot suppose South America to have had a free land commu- 
 nication with any other of the great continents in the Pliocene 
 or scarcely perhaps in the Miocene epoch ; so that even the 
 genera of quadrupeds in Europe must have changed several 
 times, while this Neotropical region has continued almost 
 as isolated as it is now. 
 
 In Peru and Chili, says Humboldt, the region of the grasses 
 is inhabited at an elevation of from 12,300 to 15,400 feet by 
 crowds of lama, guanaco, and alpaca. These quadrupeds, 
 which here represent the genus camel of the ancient conti- 
 nent, have not extended themselves either to Brazil or Mexico, 
 because, during their journey, they must necessarily have 
 descended into regions that were too hot for them.f In this 
 passage, published in 1814, it will be seen that already the 
 doctrine of specific centres was tacitly assumed. 
 
 I have already stated that extinct genera of the lama, 
 sloth,- armadillo, and many other families of South American 
 quadrupeds, have been found in the same region in a fossil 
 state. But it is remarkable that, in some points, the fossil 
 fauna is not so unlike that of the rest of the world as is the 
 recent. A species of horse, for example, has been found 
 fossil in the Pampas, and of elephant (Mastodon Andium), in 
 the mountains of Peru. So also the horse, mastodon, and 
 Siberian mammoth occur fossil throughout a considerable 
 area in North America, although there were no represen- 
 tatives of any of these genera extant in the New World when 
 it was first colonised by Europeans. 
 
 The former wide range of these quadrupeds implies a 
 migration of Old- World forms into the New World, perhaps 
 by way of the Andes, in Pliocene times ; but how this in- 
 
 * See above, Vol. I. p. 253. 
 
 f Description of the Equatorial Kegions : 1814. 
 
CH. XXXVIII.] ANIMALS OF THE NEOTEOPICAL REGION. 337 
 
 vasion was brought about, and by what causes the Old -World 
 species were again exterminated, we cannot conjecture. It 
 may, however, be affirmed that we are by no means entitled, 
 in the present state of our knowledge, to wonder at the 
 extinction of any species. A small insect, which lays its 
 eggs in the navels of horses, cattle, and dogs, when first born, 
 makes it impossible, says Darwin, for any of these animals 
 to run wild in Paraguay ;* and we are extremely ignorant as 
 to the various animals and plants, on the coexistence of 
 which the well-being of any one species may depend. 
 
 Besides, as geologists, we must remember that the horse 
 tribe and the elephants have been waning groups since the 
 Miocene and Pliocene periods in the northern hemisphere. 
 In northern India alone, the fossil remains of the Sewalik 
 hills have shown us that there were in the Upper Miocene 
 Period no less than seven distinct species of proboscidians of 
 the genera Elephas, Mastodon, and Stegodon (as defined by 
 Falconer), and besides these several species of mastodon 
 flourished contemporaneously in Europe. There are now only 
 two living representatives of the whole group, viz. Elephas 
 Indicus and E. Africanus. In like manner no less than twelve 
 equine species referred by Leidy to seven genera, have been 
 already detected in the Pliocene and Post-Pliocene forma- 
 tions of the United States, no one of which survived in 
 America at the time when it was first visited by Europeans. f 
 It has been objected that the insect fauna of Chili, although 
 to a great extent peculiar to South Temperate America, 
 contains also many generic forms of butterflies and beetles, 
 such as Colias, Carabus and others, which are common to the 
 northern hemisphere, and are not found in the intermediate 
 tropical region. These insects, however, may well be sup- 
 posed to have passed from north to south along the higher 
 region of the Andes, during the cold of the Glacial Period ; 
 and almost all of them, seem to have been so modified in 
 their character, that the allied forms of the north and south 
 are not specifically identical. As to the marsupial opossums of 
 
 * Darwin, ' Origin of Species,' 4th braska Fossil Remains, Proc. of Acad. 
 edition, p. 83. Nat. Sci. Philadelp. 1858, p. 89. 
 
 f See Leidy and Hayden on Ne- 
 
 VOL. II. 
 
338 GEOGRAPHICAL DISTRIBUTION OF SPECIES. [On. XXXVIII. 
 
 America having Australian affinities, it has been justly 
 remarked by Mr. Wallace that as the genus Didelphis existed 
 in Europe in the Eocene and Lower Miocene periods, the 
 American species are much more likely to have been derived 
 from that source, assuming the origin of species by variation, 
 than from Australia, where the genus in question has not 
 hitherto been met with, whether in a fossil or living state. 
 
 In this great province, the Neotropical, as indeed in every 
 other to which we shall afterwards allude, the larger part of 
 the species are separable from each other by lines of demar- 
 cation, whether in the animal or vegetable kingdoms, suf- 
 ficiently clear to enable naturalists to agree for the most part 
 in their systems of classification; but exceptions could be given 
 in every great division, whether of the vertebrate or inverte- 
 brate class,, where species occur which pass one into the other 
 by so many intermediate gradations that scarcely any two 
 naturalists take exactly the same views as to their relation- 
 ship. Thus for example, Mr. Bates observed in the valley of 
 the Amazons swarms of a gregarious species of butterfly of 
 the elegant genus Heliconius, which is peculiar to tropical 
 America. It abounds in the shades of the forests presenting 
 clusters of allied species and varieties, as well as some better 
 marked forms. A conspicuous member of the group is H. 
 Melpomene of Linnseus, which is found throughout Guiana, 
 Venezuela, and parts of New Granada. It is very common 
 at Obydos on the north side of the Amazons, and reappears 
 on the south side of the river, in the dry forests behind 
 Santarem. But it is absent from other parts of the valley, 
 where a nearly allied species, H. Thelxiope, of the same size 
 and shape, but differing in colour, takes its place. Both 
 species have the same habits, and they have always been con- 
 sidered by entomologists as specifically distinct ; but Mr. 
 Bates came to the conclusion that one was simply a modifi- 
 cation of the other ; for he found that in those forest tracts 
 which were intermediate in character between the dryer air of 
 Obydos and the moister air of the rest of the great valley the 
 individuals of these Heliconii were transitional forms between 
 the two reputed species alluded to. He observed them to 
 pass by very slight variations from one extreme to the other, 
 
CH. XXXVIII.] MAMMALIA OF THE NEOTROPICAL REGION. 339 
 
 and yet the inference that they were hybrids produced by the 
 intercrossing of H. Melpomene and H. Thelxiope was not 
 admissible ; for the two butterflies were never seen to pair 
 with each other, and the intermediate varieties are unknown 
 in several places where the two forms come in contact. If the 
 whole district which they inhabit is contemplated, the inter- 
 mediate forms are incomparably more rare than the two ex- 
 treme terms of the series, and these last must, says Mr. Bates, 
 be treated as good and true species, because they exhibit cha- 
 racters usually regarded as sufficient for such a distinction, 
 and, amongst others, an aversion to pair together. A similar 
 course of reasoning induced the same naturalist to believe 
 in the derivation of H. Vesta from H. Melpomene, H. Vesta 
 having a very wide range, and extending into the central 
 valleys of the Andes. 
 
 The highest class of the mammalia, or the monkeys of the 
 same region, might afford us another equally apposite illus- 
 tration. There are two distinct species of Cebus, or Capuchin 
 monkey, the Caiarara (C. albifrons, Spix), and that called 
 Prego (G. cirrhifer, St. Hilaire), both found on the Amazons, 
 which differ in form and disposition. They are not local 
 varieties, for they sometimes coexist in the same district. 
 But there are so many sub-species and varieties of this same 
 monkey in equatorial America, which spread over thousands 
 of miles of wild country, and connect together the two forms 
 above mentioned, that, after comparing the whole, Mr. Bates 
 affirms that a zoologist cannot separate, by any well-defined 
 line, the two extremes of the series.* 
 
 The naming of these varieties has often been a subject of 
 great perplexity in the Zoological Gardens in London, and 
 equally so in the museums at Paris, as anyone may satisfy 
 himself by consulting the printed catalogue, drawn up by 
 Isidore Geoffroy St. Hilaire. Nor are the Capuchins the only 
 platyrrhine monkeys whose classification is embarrassing, as 
 appears by the same official document. To those who adopt 
 Mr. Darwin's views, these transitional forms are precisely 
 what we ought to encounter, for they simply imply, as before 
 hinted, p. 323, that some genera and species are comparatively 
 
 * Bates, Naturalist on the Amazons, vol. ii. p. 101. 
 z 2 
 
310 GEOGRAPHICAL DISTRIBUTION OF SPECIES. [Cn. XXXVIII. 
 
 modern, so that there has not been time for the causes of 
 extinction to make gaps in the series of new varieties. 
 
 Nearctic region. We have next to pass to the Nearctic 
 region, extending from the centre of the table-land of Mexico 
 to the North Pole. If we compare the southern limits of 
 this great province with the nearest lands on the east and 
 west, the north of Africa on the one side and China on the 
 other, we find a complete dissimilarity between the fauna of 
 the American and that of the African and Asiatic continents ; 
 but, the farther we go north and enter those latitudes where 
 the three continents approach each other, the more the dis- 
 cordance in genera and species diminishes. It has often, in- 
 deed, been said that the whole circumpolar region forms one 
 province ; but some of the American species formerly iden- 
 tified with the European the badger, for example have 
 been found to differ on closer examination, and the musk-ox 
 (Ovibos moschatus) is peculiar to America, although the same 
 animal formerly ranged, as we know from its fossil remains, 
 over Germany, France, and England. 
 
 The predominant influence of climate over all the other 
 causes which limit the range of species in the mammalia is 
 perhaps nowhere so conspicuously displayed as in the region 
 now under consideration. It will be observed that 011 this 
 continent between the Rocky Mountains and the Atlantic 
 there are no great geographical barriers running east and 
 west, such as high snow-clad mountains, barren deserts, or 
 wide arms of the sea, capable of checking the free migration 
 of species from north to south. Yet the arctic fauna, so ad- 
 mirably described by Sir John Richardson, has scarcely any 
 species in common with the fauna of the state of New York, 
 which is 600 miles farther south, and comprises about forty 
 distinct mammifers. If again we travel farther south about 
 600 miles, and enter another zone, running east and west, in 
 South Carolina, Georgia, Alabama, and the contiguous states, 
 we again meet with a new assemblage of land quadrupeds, 
 and this again differs from the fauna of Texas farther to the 
 south, where frosts are unknown. But notwithstanding the 
 distinctness of those zones of indigenous mammalia, there 
 are some species, such as the buffalo (Bison Americanus), the 
 
CH. XXXVIII.] MAMMALIA OP THE PAL JE ARCTIC REGION. 341 
 
 racoon (Procyon lotor), and the Virginian opossum (Didelphis 
 Virginiana), which have a wider habitation, ranging almost 
 from Canada to the Gulf of Mexico ; but they form exceptions 
 to the general rule. The opossum of Texas (Didelphis cancri- 
 vora) is different from that of Virginia, and other species of 
 the same genus are found westward of the Rocky Mountains, 
 in California, for example, where almost all the mammalia 
 differ specifically from those in the United States. 
 
 Palcearctic region. We next come to the third or Palsearctic 
 region, comprising Europe and Northern Asia as far as Japan, 
 and also including Africa north of the desert of the Sahara. 
 Selecting our examples here, as before, chiefly from the 
 mammalia, we may first mention the extraordinary range from 
 east to west of the European species of quadrupeds ; for no 
 less than 44 of these, out of 58, are common to Europe and 
 Amoorland, or that part of North-eastern Asia which lies 
 between latitude 45 and 55 north. In the same group 
 there are some species which have not so wide a range 
 east and west, but which extend for great distances in 
 a north and south direction. Thus the tailless hare, or Pica, 
 passes far into the Arctic latitudes, and the tiger, Felis Tigris, 
 into the tropical, even as far south as Java. 
 
 The propriety of considering Morocco. Algeria, and Tunis 
 as part of the same province as Europe and Northern Asia, 
 has been questioned, but only with reference to the mammals ; 
 for the birds, reptiles, insects, and plants are all decidedly 
 of Palsearctic forms. As to the mammalia, Mr. Wallace has 
 given a table showing that no less than thirty-three of the 
 Algerian species are absolutely identical with European or 
 West- Asiatic quadrupeds ; fourteen more are representatives 
 of European genera, and ten belong to genera of Western 
 Asia and Siberia. But, on the other hand, seven or eight 
 species have been supposed to give an Ethiopian or extra- 
 European character to the North- African highlands. They 
 are all Desert-haunting species an antelope, a monkey 
 (Macacus Inuus), the same as that which inhabits the rock 
 of Gibraltar, a lion, leopard, cerval, and hunting leopard. 
 These same large feline species range through the whole of 
 Africa from the Mediterranean to the Cape, and may, says 
 
342 GEOGRAPHICAL DISTRIBUTION OF SPECIES. [Cn. XXXVIII. 
 
 Mr. Wallace, very probably have crossed the desert in the 
 tracks of caravans. If we confine our attention to the 
 genera instead of species, we find that out of thirty-one only 
 three are common to the Palsearctic and Ethiopian regions. 
 
 From what we have said in the first volume (p. 562) of 
 the submarine ridge between Gibraltar and the nearest part 
 of Africa or Tangiers (a ridge twenty-two miles long and 
 from five to seven miles broad, and nowhere covered by a 
 depth of water exceeding 220 fathoms), we learn that the 
 union of Southern Europe with Africa does not imply a 
 great change in the relative level of land and sea. The 
 geologist at least is familiar with the fact that the rising 
 and sinking of land and of the bed of the Mediterranean 
 within the Newer Pliocene Period has, in Sicily and else- 
 where, far exceeded the amount which would be required 
 to unite the coasts on the opposite side of the Straits of 
 Gibraltar. A change of level of about 70 fathoms would 
 unite Malta and Gozo with Sicily, and one of 200 fathoms 
 would join Malta to Tripoli by an isthmus 170 miles long. 
 A similar change would connect Italy with Sicily, and the 
 latter with Africa by the Adventure Bank. We can only 
 explain, by this and other analogous land communications of 
 modern geological date, the remarkable resemblance of the 
 fauna and flora of the islands of the Mediterranean and the 
 nearest mainland, notwithstanding the general depth of that 
 sea. Some of the mountainous islands, it is true, of the 
 Egean are inhabited by peculiar species of landshells, as was 
 ascertained by the late Edward Forbes and Captain Spratt ; 
 but these mountains may perhaps have been insulated from 
 a remote period, as freshwater strata of Miocene age occur 
 in parts of them, and the surrounding sea is of vast depth. 
 The remains of the African elephant and of the Elephas 
 antiquus, and of an extinct hippopotamus in Sicily, and, 
 what is more wonderful, of several species of elephant, and 
 an hippopotamus in caverns in the small island of Malta, 
 bear testimony to great geographical changes in compara- 
 tively modern or Pliocene times. 
 
 As to the distinctness above alluded to of the North- 
 African fauna from that south of the Sahara, we know that 
 
CH. XXXVIII.] MAMMALIA OF THE ETHIOPIAN REGION. 343 
 
 the Great Desert was submerged beneath the sea in the 
 Pliocene Period ; so that assuming that species have only 
 one birthplace, we can account for their distinctness in 
 these two regions, which were separated first by a barrier of 
 water and afterwards by one of sand. 
 
 The geographical distribution of reptiles agrees as a 
 general rule with that of the mammalia and birds ; but a 
 discrepancy has been pointed out in the Palsearctic region. 
 Although the batrachians of Japan are all Palsearctic, the 
 snakes agree in genera and species with those of the more 
 southern parts of Asia or the Indian region, which we 
 shall have presently to consider. Mr. Wallace suggests 
 the following explanation of this apparent anomaly : he 
 reminds us that Dr. Giinther has shown that snakes are a 
 preeminently tropical group, decreasing rapidly in the tem- 
 perate regions, and absolutely ceasing at 62 1ST., whereas 
 the batrachians are almost as largely developed in northern 
 as in tropical latitudes, being able to support, partly by aid 
 of hybernation, a very cold climate. We may therefore 
 suppose Japan to have once formed a part of Northern Asia, 
 with which it is even now almost connected by two chains 
 of islands ; in which case it might have received its birds, 
 mammals, and batrachians from the Palsearctic region, 
 whereas it could have derived but few or no snakes from the 
 same quarter, since the great cold extends to a much lower 
 latitude in Eastern Asia than in Western Europe. If at a 
 subsequent period Japan became connected with Southern 
 Asia through the Loo-choo and Majicosima islands, it might 
 then have been colonised by snakes of Indian origin, which 
 would easily establish themselves in a region unoccupied by 
 any representatives of the same class. Batrachians, on the 
 contrary, as well as the birds and mammals of Southern Asia, 
 would find a firmly established Palsearctic population ready 
 to resist the invasion of all intruders.* 
 
 Ethiopian region. The next or fourth zoological province 
 is the Ethiopian, including Africa south of the Great Desert, 
 and the island of Madagascar. That this part of Africa 
 
 * Wallace on Zoological aud Botanical Geography, Nat. Hist. Kev. 1864, p. 114. 
 
344 GEOGRAPHICAL DISTRIBUTION OF SPECIES. [Cn. XXXVIII. 
 
 should be characterised by a peculiar indigenous fauna is a 
 fact in perfect accordance with Buffon's theory of natural 
 barriers. 
 
 We have already stated that the sea even in post-tertiary 
 times covered the space now occupied by the Sahara, so that 
 Africa was for vast periods surrounded by water on every side 
 but the north-east, where it was connected by an isthmus 
 with Asia. Such a connection might explain why there are 
 some few species, such as the lion, dromedary, and jackal, 
 common to Africa and Asia, and also why many Asiatic 
 genera are represented by allied African species. The ele- 
 phant, for example, of Africa, though so nearly resembling that 
 of India, is distinct, being smaller, having a rounder head and 
 larger ears than the Indian one, and having only three instead 
 of four toes 011 each hind foot. There are three African 
 species of rhinoceros, all differing from the three Indian ones. 
 The genus hippopotamus is now represented by two species 
 exclusively African, although it occurred in India in the Mio- 
 cene Period, and in Europe in the Pliocene and Post-Pliocene. 
 Also the giraffe, the gorilla, the chimpanzee, the blue-faced 
 baboon, the four-fingered monkey (Colobus), and many carni- 
 vora, such as Proteles, allied to the hyaena. In proportion 
 as we advance towards the southern part of the Ethiopian 
 region we find in the temperate zone other forms, many of 
 them agreeing generically with those inhabiting the zone of 
 corresponding climate north of the equator in Asia. Among 
 these are the quagga and the zebra ; answering to the horse, 
 the ass, and the jiggetai of temperate Asia. Amongst 
 pachydermatous animals the hyrax is peculiar, amongst the 
 ruminantia the Cape buffalo and many antelopes, such as the 
 springbok, the oryx, the gnu, the leucophoe, the pygarga, 
 and several others. 
 
 Separated from Africa by the Mozambique channel, which 
 is 300 miles wide, Madagascar forms, with two or three small 
 islands in its immediate vicinity, a zoological sab-province, 
 of which all the species except one, and nearly all the genera, 
 are peculiar. The one exception alluded to consists of a small 
 insectivorous quadruped (Centetes), found also in the Mauri- 
 tius, to which place, however, it is supposed to have been 
 
CH. XXXVIII.] MAMMALIA OF ETHIOPIAN EEGIOX. 345 
 
 taken in ships. The most characteristic feature of this 
 remarkable fauna consists in the number of quadrumana of 
 the Lemur family, no less than six genera of those monkeys 
 being exclusively met with in this island, and a seventh 
 genus of the same, called Galago, which alone has any foreign 
 representative, being found, as we might from analogy 
 have anticipated, on the nearest mainland. Madagascar is 
 nearly as large as Great Britain, and being in the same lati- 
 tude as the adjoining part of the continent of Africa, enjoys 
 a similar climate. Had the species of quadrupeds in Mada- 
 gascar agreed with those of Africa, as do those of England 
 with the rest of Europe, the naturalist would have inferred 
 that there had been a land communication since the period 
 of the coming in of the existing quadrupeds, whereas we may 
 now conclude that the broad Mozambique channel has con- 
 stituted an insuperable barrier to the fusion of the conti- 
 nental fauna with that of the great island during the whole 
 period that has elapsed since the living species of mammalia 
 came into being. 
 
 The period when Madagascar was united to some part of 
 Africa was probably as remote as the Upper Miocene era, 
 at which time we know that the outline of the land in Europe 
 varied materially from that which it now exhibits ; so that we 
 may readily suppose the arm of the sea constituting the 
 Mozambique channel to have been dry land at that period. 
 Some of the peculiar Miocene genera may have survived on 
 the island after they became extinct on the continent, and a 
 still greater number of species. Other families, such as the 
 Lemurs, may have multiplied more in the island than on the 
 continent ; but in spite of such changes the two faunas 
 continental and insular (assuming the origin of species by 
 variation and natural selection) would continue to bear the 
 mark of having sprung from a common source at a compa- 
 ratively modern era. They would continue to have more 
 affinity with each other than with any more distant region, 
 such as the Indian or Australian. On the other hand, the 
 hypothesis of special creation helps us in no way to account 
 for such generic and family ties as bind together these two 
 sets of animals in each of which all the species are distinct. 
 
346 GEOG-KAPHICAL DISTRIBUTION OF SPECIES. [On. XXXVIII. 
 
 Indian region. We have next to consider the Indian region, 
 comprising Southern Asia and the western half of the Malay 
 archipelago. Its boundary on the side of Arabia has not yet 
 been well defined, as that country seems at present to be 
 regarded by zoologists as debateable ground between the 
 Ethiopian, Indian, and Palsearctic regions. Although the 
 Indian species are very distinct from those of Africa, a great 
 many of the genera of quadrupeds are common to both con- 
 tinents. There are, however, some forms which are peculiar 
 to the Indian region ; such as the sloth-bear (Prochilus), the 
 musk-deer (Moscus), the nylghau, the gibbon or long-armed 
 ape, and some others. 
 
 The elephant and tapir of Sumatra and Borneo are the 
 same as the Indian species, and the rhinoceros of Sumatra and 
 that of Java are each of them respectively common to Bengal 
 and Malacca. One of the gibbons or long-armed apes 
 (Hylobates leuciscus) is common to the Malay peninsula and the 
 islands of Java and Borneo, though wanting in Sumatra. 
 The wild ox of Java also occurs on the Asiatic continent. 
 None of these large animals, says Mr. Wallace, could possibly 
 have passed over the arms of the sea which now separate 
 these countries ; so that they point clearly to the existence of 
 a land communication between the islands and the mainland 
 since the origin of such mammalia. 
 
 Between 80 and 90 mammals inhabit Java, and nearly as 
 many occur in Sumatra ; more than half of these species are 
 common to the two islands. Borneo, which is much less ex- 
 plored, has yielded already upwards of 60 species, and more 
 than half of these are not met with either in Java or Sumatra. 
 As each island contains not only many species but some genera 
 peculiar to itself, the date of their former union can only be 
 spoken of as modern when we understand the term in a geo- 
 logical sense. We may feel sure, for example, that it occurred 
 during some part of the Pliocene epoch ; and this speculation 
 is rendered the more probable by the fact that a difference of 
 level of 50 fathoms, or only 300 feet, would unite Borneo, 
 Java, and Sumatra with the mainland or with Malacca and 
 Siain,* and a rise of 100 fathoms would include the Philippine 
 
 * Wallace, Physical Geography of Malay Archipelago, Geogr. Soc. Journ. 1804. 
 
CH. XXXWIL] MAMMALIA OF AUSTKALIAN KEGION. 
 
 347 
 
 Islands and Bali or the whole of the Indian region (see map, 
 fig. 132). To this question of a modern geographical change 
 we shall again refer. 
 
 In regard to the birds of the mainland, the genus Euploca- 
 mus of the pheasant family affords a good illustration of a 
 variable form. Thus E. melanotus, or black-backed kalige of 
 
 Fig. 132. 
 
 and Papuan races, showing their near coinci- 
 dence with the range of species of the inferior 
 animals (see Chap. XLIIL). 
 
 Map showing the boundaries of two great zoological provinces, the Indian and 
 the Australian, as defined by Alfred B. Wallace, Esq. The lands which are shaded 
 belong to the Australian, the unshaded to the Indian region. 
 
 a b. Line exceeding 100 fathoms in depth 
 separating the Indian and Australian zoologi- 
 cal region. 
 
 c d. Boundary line between the Malayan 
 
 Sikkim, is found to pass by numerous varieties in the inter- 
 mediate Aracan country into the E. lineatus of Tenasserim and 
 Pegu. The varieties are considered by Dr. Sclater not to be 
 hybrid forms. 
 
 Australian region and Mr. Wallace on its limits with the 
 Indian region in the Malay archipelago. Lastly, we come to 
 the sixth or Australian region, which, as we have before men- 
 
34 S BOUNDAKY OF THE INDIAN [Cn. XXXVIII. 
 
 tioned, is inhabited by mammalia belonging almost exclusively 
 to the marsupial sub-class. The only associated and indi- 
 genous placental species are a few rodents and bats. Al- 
 though the mainland of Australia is very isolated, yet when the 
 whole geological province is considered, there seems at first 
 sight to be no natural barrier sufficiently strong in a north-east 
 direction to account for the marked line of separation in the 
 islands of the Malay archipelago between the species belonging 
 to the Australian and those proper to the Indian region. 
 The geographical distribution of the two faunas, which are 
 remarkably distinct, is shown in the annexed map, all the lands 
 which are shaded belonging to the Australian and those which 
 are unshaded to the Indian region. Mr. Wallace has also 
 pointed out that the line a b, which divides two different 
 assemblages of mammalia and birds, coincides very nearly with 
 the line c 6, which divides two of the best characterised races 
 of mankind, the Malayan and the Pacific, in which last are 
 included the Papuans, Australians, and Polynesians.* 
 
 The Straits of Lombok, through which the line a l> passes 
 between the island of that name and Bali, are only fifteen 
 miles across, less wide than the Straits of Dover, and yet the 
 contrast of the animals of various classes on both sides of this 
 narrow channel is as great as that between the Old and the 
 New Worlds. In other words, the discordance, not only in 
 species but in genera, equals that which is usually caused by 
 a wide ocean rather than by straits which allow of one shore 
 being easily seen from the other. It has already been stated 
 (p. 343) that all those islands of the Malay archipelago which 
 are only separated from the mainland of Asia by a depth of 
 water of less than 100 fathoms contain a fauna which is strictly 
 Indian. Mr. Wallace, in commenting on this fact, has pointed 
 out the obvious relation of the present distribution of animals 
 and -plants with changes in the position of land and sea 
 which must be assumed to have taken place in comparatively 
 modern times. 
 
 The reader has already been told (Chapters XII., XIV., and 
 XXXI.) of the elevation and depression of the crust of the earth 
 
 * See below, Chap. XLIII. 
 
CH. XXXVIII.] AND AUSTRALIAN REGIONS. 349 
 
 and the conversion of land into sea and sea into land, with 
 which geology has made us acquainted, and of the accompany- 
 ing fluctuations in the state of the organic world. Taking 
 these for granted, we may expect to find proofs that some 
 islands were once united with each other or with the neigh- 
 bouring continents at comparatively recent periods. Where 
 this has happened, the same species of animals and plants 
 will be found to be common to the lands now disjoined, and 
 the seas which divide them will usually be shallow. But if 
 the natural productions are dissimilar, we may safely speculate 
 011 the separation having taken place at a more remote epoch, 
 as in the case before mentioned of Madagascar and Africa, 
 where we have seen that the intervening sea is very deep. 
 
 The line a b in the map, fig. 132, indicates a line of sound- 
 ing exceeding 100 fathoms, the sea to the westward of this 
 line having everywhere a depth of less than 100 fathoms ; and 
 here we find the limits of the two faunas, the Indian and the 
 Australian, very sharply defined. When speaking of the 
 contrast of the animals inhabiting the two regions Mr. 
 Wallace says : i In Australia there are no apes or monkeys, no 
 cats or tigers ; no wolves, bears, or hysenas ; no deer, or sheep, 
 or oxen ; no elephant, horse, squirrel, or rabbit ; none, in short, 
 of those familiar types of quadrupeds which are met with on 
 the Indian area. Instead of these Australia has its marsupials, 
 kangaroos, opossums, and wombats, and the representatives of 
 a still lower division of the mammalia, the duck-billed Platy- 
 pus (or Ornithorynchus) , and the Echidna. Its birds,' he 
 continues, ' are almost as peculiar : it has no woodpeckers and 
 no pheasants, families which exist in every other part of the 
 world. But instead of them it has the mound-making brush- 
 turkeys, the honeysuckers, the cockatoos, and the brush- 
 tongued Lories, which are found nowhere else upon the globe.'* 
 
 If we cross the straits from Lombok to Bali, which we may 
 do in two hours, we find on the western side a complete con- 
 trast in animal life. We meet, for example, with barbets, 
 fruit-thrushes, and woodpeckers; instead of honeysuckers 
 and brush-turkeys. In like manner, if we travel from Java 
 
 * Wallace, Physical Geography of Malay Archipelago, Journal of Geogra- 
 phical Society, 1864. 
 
350 BOUNDARY OF THE INDIAN [Cn. XXXVIII. 
 
 or from Borneo, and pass over to Celebes, the Moluccas, and 
 New Guinea, the difference is almost equally striking. In Java 
 or Borneo the forests abound in monkeys of many kinds, and 
 wild cats, deer, civets, otters, and squirrels are constantly met 
 with. In Celebes or the Moluccas, none of these occur, but 
 the prehensile-tailed opossum is the terrestrial animal most 
 seen. Some pigs, however, and deer of Indian types, probably 
 introduced by man, are met with. 
 
 Mr. Wallace moreover reminds us that the diversity in the 
 natural productions of the two great regions does not corre- 
 spond to any of the physical or climatal divisions of the 
 surface. On both sides of the line of demarcation we find in 
 the same latitude islands of volcanic origin similar in soil, 
 elevation, moisture, dryness, and fertility, and equally covered 
 with forests. How then are we to explain the distinctness 
 of the two faunas ? The greater depth of the sea which sepa- 
 rates the lands east of the line a b (fig. 132) from those to 
 the west of it would lead us to speculate on a longer period 
 of separation. Still it may be asked, how is it possible to 
 conceive that a channel in one place only fifteen miles wide 
 should have been so effective in arresting the migration of 
 species from one region into the other ? Before we give an 
 account of Mr. Wallace's speculations on this head, we must 
 state, that marked as is the contrast on the opposite sides of 
 the line a fc, some colonisation from one province to the other 
 has already begun, although less perhaps than along any one 
 of the points of contact of the five great zoological provinces 
 before described. In Lombok there are several mammalia 
 of the placental class. The largest of them is the ape called 
 Macacus cynomolgus. As to the wild pig it may have been 
 introduced by man, and the same may be said of the Moluccan 
 deer, which occurs in the island of Timor. The Paradoxurus 
 musanga of the weasel tribe, also found in many of these 
 islands east of the line a b, is an animal often domesticated. 
 But a shrew-mouse and a feline animal, Fells megalotus, 
 peculiar to Timor, are less easily explained; unless, indeed, 
 our acquaintance with the mammalia of Java is still defective, 
 a supposition by no means improbable. The squirrels extend 
 from Lombok eastward as far as Sumbawa, but no farther. 
 
CH. XXXVIII.] AND AUSTRALIAN EEGIONS. 351 
 
 Iii the case of Borneo and Celebes there seems to have 
 been a partial fusion of the mammalia at some remote period, 
 as there is a species of baboon, a wild cat, and a squirrel in 
 Celebes, all belonging to Indian genera; but that so few of the 
 mammals of Borneo should have reached Celebes, and that 
 there should be hardly a land-bird in common and very few 
 insects, is, perhaps, says Mr. Wallace, even more extraordi- 
 nary than the distinctness of the fauna of Bali and Lonibok ; 
 for the two latter islands being wholly of volcanic origin, may 
 be comparatively modern, whereas Borneo and Celebes must 
 from their great size and altitude be very ancient. Between 
 the latter also, although the sea is much wider than in the 
 Straits of Lombok, there is a great extent of opposing coasts 
 which would be very favourable to mutual immigration. 
 
 It is a singular fact that there are distinct species of 
 wild pig in almost every large island, as in Sumatra, Borneo, 
 Java, New Guinea, and Timor, and one or more other 
 species are said to inhabit Gilolo. Some of these may 
 have been introduced by man at so remote a period as to 
 have varied greatly from the parent stock ; for if the pre- 
 vailing opinion be correct, that the Japanese pigs, of which 
 specimens were lately exhibited in our Zoological Gardens, 
 be mere varieties of the domesticated Bus Indica, we may 
 imagine a little more divergence to be sufficient to constitute 
 a true species. We shall see in the next chapter that pigs 
 have been known, when swept by a flood into the sea, to swim 
 for great distances, so that some of them may have passed 
 in this manner from island to island. 
 
 That so few quadrupeds, birds, and insects have obtained 
 a footing on the opposite sides of such channels as those 01 
 Lombok or the Macassar Straits, seems the more strange, 
 when we reflect on well-known instances of birds even of 
 weak flight having sometimes been carried by the wind 
 during heavy gales over wide spaces of sea. But the power 
 of preoccupancy is great in enabling the old indigenous in- 
 habitants to prevent stray individuals of foreign species 
 from effecting a permanent settlement. As to the Straits of 
 Lombok, they are very narrow, but there is so rapid a marine 
 current always running through them, that it might easily 
 
352 BOUNDARY OF THE INDIAN [Cn. XXXVIII. 
 
 prevent quadrupeds and reptiles from swimming across from 
 shore to shore. 
 
 To assist us in accounting for the marked separation 
 between the Indian and Australian faunas, as well as for 
 many partial exceptions to the distinctness of the two 
 groups of animals in some of the islands of the Malay 
 archipelago, Mr. Wallace has suggested an imaginary 
 parallel, of which I can only give a brief outline. Suppose 
 the bed of the Atlantic to be gradually converted into land, 
 partly by the deposition of large bodies of sediment poured 
 down by rivers, and partly by slow upheaval and volcanic 
 action. Let the two continents of Africa and America be 
 thus more and more extended, so that the ocean, which now 
 separates them, should at last be reduced to an arm of the 
 sea a few hundred miles wide. Let us, at the same time, 
 imagine several islands to be upheaved in mid-channel, and 
 that, while the subterranean forces varied in intensity and 
 shifted their points of greatest action, these islands became 
 sometimes connected with the main land on one side of the 
 strait, and sometimes with the land on the other side. Two 
 or more of the islands also might occasionally be joined to- 
 gether and then broken up again, till at last, after many ages 
 of such intermittent action, with many a long intervening 
 period of comparative tranquillity, we might have an irre- 
 gular archipelago of islands filling up the ocean channel of 
 the Atlantic, in whose appearance and arrangement we could 
 discover nothing to tell us which had been connected with 
 Africa and which with America. But the animals and plants 
 inhabiting these islands would certainly reveal this portion of 
 their former history. On those islands which had ever formed 
 a part of the South American continent we should be certain 
 to find such common birds, as chatterers, toucans, macaws, 
 and humming-birds, and some peculiar quadrupeds, such as 
 spider-monkeys, pumas, tapirs, ant-eaters, and sloths ; while, 
 on the islands which had been separated from Africa, we 
 should be equally sure to meet with horn-bills, orioles, and 
 honeysuckers, and some quadrupeds contrasting strongly 
 with those of South America, such as baboons, lions, ele- 
 phants, buffaloes, and giraffes. Those intermediate islands 
 
CH. XXXVIII.] AND AUSTRALIAN REGIONS. 353 
 
 which at different times had had a temporary connection 
 with either continent, would contain a certain amount of 
 mixture in their living inhabitants. Such seems to Mr. 
 Wallace to have been the case with the islands of Celebes 
 and the Philippines. Other islands, again, though in such 
 close proximity as Bali and Lombok, might each exhibit an 
 almost unmixed sample of the productions of the continents 
 of which they had directly or indirectly once formed a part. 
 
 In the Malay archipelago we have indications of a vast 
 Australian continent which once reached westward to the 
 island of Celebes, and was characterised by a very peculiar 
 fauna and flora ; the western part of this continent was 
 afterwards broken up gradually and irregularly into islands. 
 At the same time Asia, which at first was separated from the 
 Australian continent by a wide ocean, appears to have been 
 extending its limits in a north-east direction in an unbroken 
 mass, so as to include Sumatra, Java, and Borneo, and pro- 
 bably reaching as far as the present 100 fathom line of 
 soundings, or as far as the boundary line a b, map, fig. 132. 
 Afterwards the south-eastern portion of this land was sepa- 
 rated into islands as we now see it, some of them coming 
 into almost actual contact with the scattered fragments of 
 the great Southern or Australian land. 
 
 There are some peculiarities in the distribution of animals 
 and plants in oceanic islands which have a more direct and 
 obvious bearing on the question of the origin of species by 
 variation than the grouping of species on continental tracts. 
 I shall therefore consider that subject in a separate chapter ;* 
 but as I shall be unable to reason on the somewhat ex- 
 ceptional facts which these islands present in relation to 
 theories of the origin of species, without constantly adverting 
 to the relative powers of migration which different species 
 enjoy, I shall treat of this latter subject first in order, and 
 then allude to the insular faunas and floras. 
 
 * Chapter XLI. 
 
 VOL. II. A A 
 
354 
 
 CHAPTEE XXXIX. 
 
 ON THE MIGKATION AND DIFFUSION OF TEREESTEIAL ANIMALS. 
 
 MIGRATION OF QUADRUPEDS MIGRATORY INSTINCTS DRIFTING OF ANIMALS 
 
 ON ICE-FLOES MIGRATION OF BIRDS MIGRATION OF REPTILES INVOLUN- 
 TARY AGENCY OF MAN IN THE DISPERSION OF ANIMALS. 
 
 MIGRATION OF QUADRUPEDS. Before we consider the geo- 
 graphical distribution of aquatic animals, it may be useful to 
 enquire what facilities the terrestrial species enjoy of spread- 
 ing themselves over the surface of the earth. The tendency 
 of each species to multiply is so great, that unless checked 
 it would soon extend its range over as wide an area as is ac- 
 cessible to it. Whether it feed on plants or prey on other 
 animals, it will not cease to enlarge the boundaries of its 
 habitation until its progress is arrested by some rival species 
 better fitted to the soil, climate, and organic conditions of 
 the country ; or by some lofty and unbroken chain of moun- 
 tains which it cannot scale, or by a desert, or the sea, or by 
 cold or heat, or some other barrier. 
 
 Mr. Wallace and Mr. Bates have shown that large rivers 
 such as the Amazons and Rio Negro are capable of forming 
 effective barriers to the farther spread of many species of 
 monkeys. This happens even where the same kind of forest 
 occurs on the opposite banks. Mr. Darwin also mentions 
 that the biscacha, a rodent somewhat resembling a large 
 rabbit, which abounds in the Pampas, although it has crossed 
 the broader river Parana, has never been able to extend its 
 range across the Uruguay. Geology teaches us that the 
 present continents have been formed by the union of large 
 pre-existing islands ; and what were formerly straits of the 
 sea have often become, under a new arrangement of the land, 
 broad valleys and the channels of great rivers such as the 
 Amazons 3 the Orinoco, and the La Plata. It is therefore 
 
CH. XXXIX.] DIFFUSION OF QUADRUPEDS. 355 
 
 probable that the real obstacle to the farther spread of many 
 species is not their inability to swim over large rivers, but 
 the pre-occupancy of the land on the farther side by an assem- 
 blage of animals fitted for all the stations which the region 
 affords. If an intruder attempts to colonise he is overpowered 
 by a rival species already established in great numbers.* 
 But for such resistance scarcely any quadrupeds would be 
 stopped by rivers and narrow friths ; for the greater part of 
 them swim well, and few are without this power when urged 
 by danger and pressing want. Thus, amongst beasts of 
 prey, the tiger is seen swimming about among the islands 
 and creeks in the delta of the Ganges, and the jaguar tra- 
 verses with ease the largest streams in South America. f 
 The bear, also, and the bison, cross the current of the Missis- 
 sippi. The popular error, that the common swine cannot 
 escape by swimming when thrown into the water, has been 
 contradicted by several curious and well-authenticated in- 
 stances during the floods in Scotland of 1829. One pig, only 
 six months old, after havingbeen carried down from Garmouth 
 to the bar at the mouth of the Spey, a distance of a quarter 
 of a mile, swam four miles eastward to Port Gordon, and 
 landed safe. Three others, of the same age and litter, swam, 
 at the same time, five miles to the west, and landed at 
 Blackhill. 
 
 In an adult and wild state, these animals would doubtless 
 have been more strong and active, and might, when hard 
 pressed, have performed a much longer voyage, especially if 
 aided by powerful tides and currents. Hence islands many 
 miles distant from a continent may obtain inhabitants by 
 casualties which, like the storms of 1829 in Moray shire, may 
 only occur once in many centuries, or thousands of years, 
 under all the same circumstances. 
 
 The late Edward Forbes told me that when he was on 
 board a surveying vessel commanded by Lieutenant Graves, 
 ~R. N. in the Grecian archipelago, the sailors amused them- 
 selves with setting a terrier at a domestic pig which they 
 had recently purchased. The animal being worried, threw 
 
 * Andrew Murray. Geographical Distribution of Mammalia, 1866, p. 18. 
 f Buffon, vol. v. p. 204. 
 
 A A 2 
 
356 MIGRATION AND DIFFUSION [CH. XXXIX. 
 
 himself overboard and made for the nearest land in sight, 
 which was many miles distant. As the pig was more fit for 
 the table than for feats of agility, and as the reputation of 
 his tribe for swimming stood very low, the sailors were 
 slow in getting out the boat to give chase, so that the 
 animal having a fair start, landed soon after sunset, just as 
 they came up to him, and further pursuit in the dark was 
 impossible. 
 
 The power of crossing rivers is essential to the elephant in 
 a wild state, for the quantity of food which a herd of these 
 animals consumes renders it necessary that they should be 
 constantly moving from place to place. The elephant crosses 
 the stream in two ways. If the bed of the river be hard, and 
 the water not of too great a depth, he fords it. But when he 
 crosses great rivers, such as the Ganges and the Mger, the 
 elephant swims deep, so deep that the end of his trunk only 
 is out of the water ; for the complete immersion of his body 
 is a matter of indifference to him, provided he can bring the 
 tip of his trunk to the surface, so as to breathe the external 
 air. 
 
 Animals of the deer kind frequently take to the water, 
 especially in the rutting season, when the stags are seen 
 swimming for several leagues at a time, from island to island, 
 in search of the does, especially in the Canadian lakes ; and 
 in some countries where there are islands near the sea-shore, 
 they fearlessly enter the sea and swim to them. In hunting 
 excursions, in North America, the elk of that country is 
 frequently pursued for great distances through the water. 
 
 The large herbivorous animals, which are gregarious, can 
 never remain long in a confined region, as they consume so 
 much vegetable food. The immense herds of bisons (Bos 
 Americanus) which often, in the great valleys of the Mississippi 
 and its tributaries, blacken the surface of the prairie lands, 
 are continually shifting their quarters, followed by wolves, 
 which prowl about in their rear. f lt is no exaggeration,' 
 says Mr. James, c to assert, that in one place, on the banks 
 of the Platte, at least ten thousand bisons burst on our sight 
 in an instant. In the morning we again sought the living 
 
CH. XXXIX.] OF QUADRUPEDS. 357 
 
 picture ; but upon all the plain, which last evening was so 
 teeming with noble animals, not one remained.'* 
 
 Migratory instincts. Besides the disposition common to the 
 individuals of every species slowly to extend their range in 
 search of food, in proportion as their numbers augment, a 
 migratory instinct often developes itself in an extraordinary 
 manner, when, after an unusually prolific season, or upon a 
 sudden scarcity of provisions, great multitudes are threatened 
 with famine. It may be useful to enumerate some examples of 
 these migrations, because they may put us upon our guard 
 against attributing a high antiquity to a particular species 
 merely because it is diffused over a great space : they show 
 clearly how soon, in a state of nature, any species might spread 
 itself in every direction, from a single point, and how the 
 territory of one animal may be invaded by another, leading 
 occasionally to the extermination of the weaker species. 
 
 In very severe winters, great numbers of the black bears of 
 America migrate from Canada into the United States ; but in 
 milder seasons, when they have been well fed, they remain 
 and hybernate in the north, f The rein-deer, which in Scan- 
 dinavia, scarcely ever ranges to the south of the sixty-fifth 
 parallel, descends, in consequence of the greater coldness of 
 the climate, to the fiftieth degree in Chinese Tartary, and 
 often roves into a country of more southern latitude than any 
 part of England. 
 
 In Lapland, and other high latitudes, the common squirrels, 
 whenever they are compelled, by want of provisions, to quit 
 their usual abodes, migrate in amazing numbers, and travel 
 directly forwards, allowing neither rocks nor forests, nor the 
 broadest waters to turn them from their course. In like 
 manner the small Norway rat sometimes pursues its migrations 
 in a straight line across rivers and lakes ; and Pennant informs 
 us, that when the rats, in Kamtschatka, become too numerous, 
 they gather together in the spring, and proceed in great bodies 
 westward, swimming over rivers, lakes, and arms of the sea. 
 Many are drowned or destroyed by water-fowl or fish. As 
 
 * Expedition from Pittsburg to the f Richardson's Fauna Boreali-Ame- 
 
 Rocky Mountains, vol. ii. p. 153. ricana, p. 16. 
 
358 MIGRATION AND DIFFUSION [On. XXXIX. 
 
 soon as they have crossed the river Penginsk, at the head of 
 the gulf of the same name, they turn southward, and reach 
 the rivers Judoma and Okotsk by the middle of July ; a district 
 more than 800 miles distant from their point of departure. 
 
 The lemings, also, a small kind of rat, are described as 
 natives of the mountains of Kolen, in Lapland; and once 
 or twice in a quarter of a century they appear in vast numbers, 
 advancing along the ground and c devouring every green 
 thing.' Innumerable bands march from the Kolen, through 
 Northland and Finmark, to the Western Ocean, which they 
 immediately enter ; and after swimming about for some time, 
 
 Fig. 133. 
 
 The Leming or Lapland Marmot (Mus Lemmus, Linn.) 
 
 perish. Other bands take their route through Swedish 
 Lapland, to the Bothnian Gulf, where they are drowned in 
 the same manner. They are followed in their journeys by 
 bears, wolves, and foxes, which prey upon them incessantly. 
 They generally move in lines, which are about three feet from 
 each other, and exactly parallel, going directly forward 
 through rivers and lakes ; and when they meet with stacks of 
 hay or corn, gnawing their way through them instead of 
 passing round.* These excursions usually precede a rigorous 
 winter, of which the lemings seem in some way forewarned. 
 
 Vast troops of the wild ass, or onager of the ancients, which 
 inhabit the mountainous deserts of Great Tartary, feed, during 
 the summer, in the tracts east and north of Lake Aral. In 
 the autumn they collect in herds of hundreds, and even 
 thousands, and direct their course towards the north of India, 
 and often to Persia, to enjoy a warm retreat during winter. f 
 Bands of two or three hundred quaggas (a species of wild ass) 
 are sometimes seen to migrate from the tropical plains of 
 
 * Phil. Trans., vol. ii. p. 872. f Wood's Zoography, vol. i. p. 11. 
 
CH. XXXIX.] OF QUADRUPEDS. 359 
 
 Southern Africa to the vicinity of the Malaleveen Eiver. 
 During their migrations they are followed by lions, who 
 slaughter them night by night.* 
 
 The migratory swarms of the springbok, or Cape antelope, 
 afford another illustration of the rapidity with which a species 
 under certain circumstances may be diffused over a continent. 
 When the stagnant pools of the immense deserts south of the 
 Orange Eiver dry up, which often happens after intervals of 
 three or four years, myriads of these animals desert the parched 
 soil, and pour down like a deluge on the cultivated regions 
 near the Cape. The havoc committed by them resembles that 
 of the African locusts ; and so crowded are the herds, that 
 6 the lion has been seen to walk in. the midst of the compressed 
 phalanx with only as much room between him and his victims 
 as the fears of those immediately around could procure by 
 pressing outwards.' f 
 
 Dr. Horsfield mentions a singular fact in regard to the 
 geographical distribution of the Mydaus meliceps, an animal 
 intermediate between the polecat and badger. It inhabits 
 Java, and is ' confined exclusively to those mountains 
 which have an elevation of more than 7,000 feet above the 
 level of the ocean ; and there it occurs with the same regu- 
 larity as many plants. The long-extended surface of Java, 
 
 Fig. 134. 
 
 Mydaus raeliceps, or badger-headed Mydaus. Length, including the tail, 16 inches. 
 
 abounding with isolated volcanos with conical points which 
 exceed this elevation, affords many places favourable for its 
 resort. On ascending these mountains, the traveller scarcety 
 fails to meet with this animal, which, from its peculiarities, 
 
 * On the authority of Mr. Campbell. f Cuvier's Animal Kingdom by G-rif- 
 
 Lil.rary of Entert. Know., Menageries, fiths, vol. ii. p. 109. Library of Entert. 
 vol. i. p. 152. Know., Menageries, vol. i. p. 3G6. 
 
360 DRIFTING OF ANIMALS [On. XXXIX. 
 
 is universally known to the inhabitants of these elevated tracts, 
 while to those of the plains it is as strange as an animal from 
 a foreign country. In my visits to the mountainous districts, 
 I uniformly met with it ; and, as far as the information of the 
 natives can be relied on, it is found on all the mountains.' * 
 
 Now, if asked to conjecture how the Mydaus arrived at the 
 elevated regions of each of these isolated mountains, we might 
 say that, before the island was peopled by man, by whom their 
 numbers are now thinned, they may occasionally have multi- 
 plied so as to be forced to collect together and migrate : in 
 which case, notwithstanding the slowness of their motions, 
 some few would succeed in reaching another mountain, some 
 twenty, or even, perhaps, fifty miles distant ; for although the 
 climate of the hot intervening plains would be unfavourable 
 to them, they might support it for a time, and would find there 
 abundance of insects on which they feed. Volcanic eruptions, 
 which, at different times, have covered the summits of some of 
 those lofty cones with sterile sand and ashes, may have 
 occasionally contributed to force on these migrations. 
 
 Drifting of animals on ice-floes. The power of the terrestrial 
 mammalia to cross the sea is very limited, and it was before 
 stated that the same species is scarcely ever common to 
 districts widely separated by the ocean. If there be some 
 exceptions to this rule, they generally admit of explanation ; 
 for there are natural means whereby some animals may be 
 floated across the water, and the sea may in the course of ages 
 wear a wide passage through a neck of land, leaving indi- 
 viduals as a species on each side of the new channel. Polar 
 bears are known to have been frequently drifted on the ice 
 from Greenland to Iceland : they can also swim to considerable 
 distances, for Captain Parry, on the return of his ships 
 through Barrow's Straits, met with a bear swimming in the 
 water about midway between the shores, which were about 
 forty miles apart, and where no ice was in sight.^ ' Near 
 the east coast of Greenland,' observes Scoresby, c they have 
 been seen on the ice in such quantities, that they were com- 
 pared to flocks of sheep on a common ; and they are often 
 
 * Horsfield, Zoological Researches in f Append, to Parry's Second Voyage, 
 
 Java, No. ii., from which the figure is years 1819-20. 
 taken. 
 
CH. XXXIX.] ON ICE-FLOES. 361 
 
 found on field-ice, above two hundred miles from the shore.' * 
 Wolves, in the arctic regions, often venture upon the ice near 
 the shore, for the purpose of preying upon young seals, which 
 they surprise when asleep. When these ice-floes get detached, 
 the wolves are often carried out to sea ; and though some may 
 be drifted to islands or continents, the greater part of them 
 perish, and have been often heard in this situation howling 
 dreadfully, as they die by famine.f 
 
 Diiriiig the short summer which visits Melville Island, 
 various plants push forth their leaves and flowers the moment 
 the snow is off the ground, and form a carpet spangled with 
 the most lively colours. These secluded spots are reached 
 annually by herds of musk-oxen and rein-deer, which, migra- 
 ting from the North- American continent, traverse the ice for 
 hundreds of miles to graze undisturbed on these luxuriant 
 pastures. J The rein-deer often pass along in the same manner, 
 by the chain of the Aleutian Islands, from Behring's Straits 
 to Kamtschatka, subsisting on the moss found in these islands 
 during their passage. But the musk-ox, notwithstanding 
 its migratory habits, and its long journeys over the ice, does 
 not exist either in Asia or Greenland. || 
 
 On floating islands of drift-wood. Within the tropics there 
 are no ice-floes ; but, as if to compensate for that mode of 
 transportation, there are floating islets of matted trees, which 
 are often borne along through considerable spaces. These are 
 sometimes seen sailing at the distance of fifty or one hundred 
 miles from the mouth of the Ganges, with living trees standing 
 erect upon them. The Amazons, the Orinoco, and the Congo 
 also produce these verdant rafts, which are formed in the 
 manner already described when speaking of the great raft of 
 the Atchafalaya, an arm of the Mississippi, where a natural 
 bridge of timber, ten miles long, and more than two hundred 
 yards wide, existed for more than forty years, supporting a 
 luxuriant vegetation, and rising and sinking with the water 
 which flowed beneath it. 
 
 * Account of the Arctic Eegions, of Discovery, p. 189. 
 vol. i. p. 518. G-odman's American Nat. Hist., 
 
 f Turton in a note to Goldsmith's vol. i. p. 22. 
 Nat. Hist., vol. iii. p. 43. || Dr. Eichardson, Brit. Assoc. Ee- 
 
 J Supplement to Parry's First Voyage port, vol. v. p. 161. 
 
3G2 DEIFTING OF ANIMALS [Cn. XXXIX. 
 
 On these green islets of the Mississippi, young trees take 
 root, and the water-lily or nenuphar displays its yellow 
 flowers : serpents, birds, and the cayman alligator come to 
 repose there, and all are sometimes carried to the sea, and 
 engulphed in its waters. 
 
 Spix and Martius relate that, during their travels in Brazil, 
 they were exposed to great danger while ascending the 
 Amazons in a canoe, from the vast quantity of drift-wood con- 
 stantly propelled against them by the current ; so much so, 
 that their safety depended on the crew being always on the 
 alert to turn aside the trunks of trees with long poles. The 
 tops alone of some trees appeared above water, others had 
 their roots attached to them with so much soil that they 
 might be compared to floating islets. On these, say the travel- 
 lers, we saw some very singular assemblages of animals, 
 pursuing peacefully their uncertain way in strange companion- 
 ship. On one raft were several grave-looking storks, perched 
 by the side of a party of monkeys, who made comical gestures, 
 and burst into loud cries, 011 seeing the canoe. On another 
 was seen a number of ducks and divers, sitting by a group 
 of squirrels. Next came down, upon the stem of a large 
 rotten cedar-tree, an enormous crocodile, by the side of a tiger- 
 cat, both animals regarding each other with hostility and 
 mistrust, but the saurian being evidently most at his ease, as 
 conscious of his superior strength.* 
 
 Similar green rafts, principally composed of canes and 
 brushwood, are called c camelotes ' on the Parana in South 
 America; and they are occasionally carried down by in- 
 undations, bearing on them the tiger, cayman, squirrels, and 
 other quadrupeds, which are said to be always terror-stricken 
 011 their floating habitation. ~No less than four tigers (pumas) 
 were landed in this manner in one night at Monte Video, lat. 
 35 S., to the great alarm of the inhabitants, who found them 
 prowling about the streets in the morning. f 
 
 In a memoir published in the United Service Journal (No. 
 XXIV. p. 697) a naval officer relates that, as he returned from 
 
 * Spix and Martius, Keise, &c., vol. p. 187, and Eobertson's Letters on Pa- 
 iii. pp. 1011, 1013. raguay, p. 220. 
 
 f Sir W. Parish's Buenos Ayres, 
 
CH. XXXIX.] ON FLOATING ISLANDS. 363 
 
 China by the eastern passage he fell in, among the Moluccas, 
 with several small floating islands of this kind, covered with 
 mangrove-trees interwoven with underwood. The trees and 
 shrubs retained their verdure, receiving nourishment from a 
 stratum of soil which formed a white beach round the margin 
 of each raft, where it was exposed to the washing of the waves 
 and the rays of the sun. The occurrence of soil in such situa- 
 tions may easily be explained ; for all the natural bridges of 
 timber which occasionally connect the islands of the Ganges, 
 Mississippi, and other rivers, with their banks, are exposed 
 to floods of water, densely charged with sediment. 
 
 The late Admiral W. H. Smyth informed me, that, when 
 cruising in the Cornwallis amidst the Philippine Islands, he 
 saw more than once, after those dreadful hurricanes called 
 typhoons, floating masses of wood, with trees growing upon 
 them ; the ships have sometimes been in imminent peril, 
 as these islands were often mistaken for terra firma, when, in 
 fact, they were in rapid motion. 
 
 It is highly interesting to trace, in imagination, the effects 
 of the passage of these rafts from the mouth of a large river 
 to some archipelago, raised from the deep by the operations 
 of the volcano and the earthquake. If a storm arise, and 
 the frail vessel be wrecked, still many a bird and insect may 
 succeed in gaining, by flight, some island of the newly-formed 
 group, while the seeds and berries of herbs and shrubs, which 
 fall into the waves, may be thrown upon the strand. But if 
 the surface of the deep be calm, aud the rafts are carried 
 along by a current, or wafted by some slight breath of air 
 fanning the foliage of the green trees, it may arrive, after a 
 passage of several weeks, at the bay of an island, into which 
 its plants and animals may be poured out as from an ark, and 
 thus a colony of several hundred new species may at once be 
 naturalised. 
 
 Although the transportation of such rafts may be of ex- 
 tremely rare and accidental occurrence, and may happen only 
 once in thousands or tens of thousands of years, they may yet 
 account in tropical countries for the extension of some species 
 of mammalia, birds, insects, landshells, and plants to lands 
 which without such aid they could never have reached. 
 
364 MIGRATION OF BIRDS. [On. XXXIX. 
 
 Migration of birds. It was before stated that birds, not- 
 withstanding their great locomotive powers, form no excep- 
 tion to the general rule, that groups of distinct species are 
 circumscribed within definite limits. 
 
 In parallel zones of the northern and southern hemispheres, 
 a great general correspondence of form is observable, both in 
 the aquatic and terrestrial birds ; but there is rarely any spe- 
 cific identity : and this phenomenon is remarkable, when we 
 consider the readiness with which some birds, not gifted with 
 great powers of flight, shift their quarters to different regions, 
 and the facility with which others, possessing great strength 
 of wing, perform their aerial voyages. Many species migrate 
 periodically from high latitudes, to avoid the cold of winter, 
 and the accompaniments of cold, scarcity of insects and 
 vegetable food. For this purpose, they often traverse the 
 ocean for thousands of miles, and recross it at other periods, 
 with equal security. 
 
 Periodical migrations, no less regular, are mentioned by 
 Humboldt, of many American water-fowl, from one part of the 
 tropics to another, in a zone where there is the same tempe- 
 rature throughout the year. Immense flights of ducks leave 
 the valley of the Orinoco, when the increasing depth of its 
 waters and the flooding of its shores prevent them from 
 catching fish, insects, and aquatic worms. They then betake 
 themselves to the Eio Negro and the Amazons, having passed 
 from the eighth and third degrees of north latitude to the first 
 and fourth of south latitude, directing their course south- 
 south-east. In September, when the Orinoco decreases and 
 reenters its channel, these birds return northwards.* 
 
 The insectivorous swallows which visit our island would 
 perish during winter, if they did not annually repair to 
 warmer climes. It is supposed that in these aerial excursions 
 the average rapidity of their flight is not less than fifty miles 
 an hour ; so that, when aided by the wind, they soon reach 
 warmer latitudes. Spallanzani calculated that the swallow 
 can fly at the rate of ninety-two miles an hour, the rapidity 
 of the swift being much greater.f Bachman says that the 
 
 * Voyage aux Regions Equinoxiales, f Fleming, Phil. Zool., vol. ii. p. 43. 
 
 torn. vii. p. 429. 
 
CH. XXXIX.] MIGKATIOX OF REPTILES. 365 
 
 hawk, wild pigeon (Columba inigratoria) , and several species 
 of wild ducks, in North America, fly at the rate of forty miles 
 an hour, or nearly a thousand miles in twenty-four hours. * 
 
 It is well known that many European birds are carried every 
 winter during violent gales of wind from Europe to the 
 Azores. Some of them are supposed to be blown from Great 
 Britain to those islands. f In performing such flights no great 
 exertion of muscular power may be required if they have 
 simply to extend their wings and allow themselves to be car- 
 ried through the air in the direction of the wind. If they 
 advance at the rate even of twenty miles an hour, they would 
 reach the islands in forty-eight hours, a period not exceeding 
 that during which many birds can sustain life without food 
 (see below, p. 414). 
 
 When we reflect how easily different species, in a great 
 lapse of ages, may be each overtaken by gales and hurricanes, 
 and, abandoning themselves to the tempest, be scattered at 
 random through various regions of the earth's surface, where 
 the temperature of the atmosphere, the vegetation, and the 
 animal productions might be suited to their wants, we shall 
 be prepared to find some species capriciously distributed, and 
 to be sometimes unable to determine the native countries of 
 each. Admiral Smyth, when engaged in his survey of the 
 Mediterranean, encountered a gale in the Gulf of Lyons, at 
 the distance of between twenty and thirty leagues from the 
 coast of France, which bore along many land-birds of various 
 species, some of which alighted on the ship, while others were 
 thrown with violence against the sails. In this manner 
 islands may become tenanted by species of birds inhabiting 
 the nearest mainland. 
 
 Migration of reptiles. Turtles migrate in large droves from 
 one part of the ocean to another during the ovipositing sea- 
 son; and they find their way annually to the island of 
 Ascension, from which the nearest land is about 800 miles 
 distant. Dr. Fleming mentions, that an individual of the 
 hawk's bill turtle (Chelonia imbricata), so common in the 
 American seas, has been taken at Papa Stour, one of the 
 
 * Silliman's Amer. Journ. No. 61, p. f Mr. F. Du Cane Godman, Ibis, vol. 
 
 83. ii. 1866, New Series. 
 
366 AGENCY OF MAN [Cn. XXXIX. 
 
 West Zetland Islands;* and, according to Sibbald, 'the 
 same animal came into Orkney.' Another was taken, in 
 1774, in the Severn, according to Turton. Two instances, 
 also, of the occurrence of the leathern tortoise (C. coriacea), on 
 the coast of Cornwall, in 1756, are mentioned by Borlase. 
 These animals of more southern seas can be considered only 
 as stragglers attracted to our shores during uncommonly warm 
 seasons by an abundant supply of food, or carried by the 
 Gulf-stream, or driven by storms to high latitudes. 
 
 Some of the smaller reptiles lay their eggs on aquatic 
 plants ; and these may often be borne rapidly by rivers, and 
 thus conveyed to distant regions. 
 
 But that even the larger ophidians may be transported 
 across the seas, is evident from the following most interesting 
 account of the arrival of one at the island of St. Vincent. It 
 is worthy of being recorded, says Mr. Guilding, 6 that a noble 
 specimen of the Boa constrictor was lately conveyed to us 
 by the currents, twisted round the trunk of a large sound 
 cedar-tree, which had probably been washed out of the bank 
 by the floods of some great South-American river, while its 
 huge folds hung on the branches, as it waited for its prey. 
 The monster was fortunately destroyed after killing a few 
 sheep, and his skeleton now hangs before me in my study, put- 
 ting me in mind how much reason I might have had to fear 
 in my future rambles through the forests of St. Yincent, had 
 this formidable reptile been a pregnant female, and escaped 
 to a safe retreat.' f 
 
 Involuntary agency of man in the dispersion of animals. In a 
 future chapter I shall speak of the transportation by man to 
 distant regions of quadrupeds and birds which are useful to 
 him, and of the effect of such colonisation in limiting the 
 range and sometimes extirpating indigenous species of plants 
 and animals. I shall merely consider in this place the invo- 
 luntary or unintentional aid which we frequently lend to the 
 dissemination of species, many of them not only unservicable 
 but noxious and injurious to us. 
 
 Thus we have introduced the rat, which was not indigenous 
 
 * Brit." Animals, p. 149, who cites Sibbald. 
 f Zool. Journ. vol. iii. p. 406. Dec. 1827. 
 
CH. XXXIX. 1 IN DISPERSION OF ANIMALS. 367 
 
 in the New World, into all parts of America. They have 
 been conveyed over in ships, and now infest a great multitude 
 of islands and parts of that continent. In like manner the 
 Norway rat (Mus decumanus) has been imported into Eng- 
 land, where it plunders our property in ships and houses. 
 
 Among birds, the house-sparrow may be cited as a species 
 known to have extended its range with the tillage of the 
 soil. During the last century it has spread gradually over 
 Asiatic Russia towards the north and east, always fol- 
 lowing the progress of cultivation. It made its first ap- 
 pearance on the Irtisch in Tobolsk, soon after the Russians 
 had ploughed the land. It came in 1735 up the Obi to 
 Beresow, and four years after to Naryn, about fifteen degrees 
 of longitude farther east. In 1710, it had been seen in the 
 higher parts of the coast of the Lena, in the government of 
 Irkutzk. In all these places it is now common, but is not 
 yet found in the uncultivated regions of Kamtschatka.* 
 
 The great viper (Fer de lance), a species no less venomous 
 than the rattlesnake, which now ravages Martinique and St. 
 Lucia, was accidentally introduced by man, and exists in no 
 other part of the West Indies. 
 
 Many parasitic insects which attack our persons, and some 
 of which are supposed to be peculiar to our species, have 
 been carried into all parts of the earth, and have as high a 
 claim as man to a universal geographical distribution. 
 
 A great variety of insects have been transported in ships 
 from one country to another, especially in warmer latitudes. 
 The European house-fly has been introduced in this way into 
 all the South Sea Islands. Notwithstanding the coldness of 
 our climate in England, we have been unable to prevent the 
 cockroach (Blatta orientalis) from entering and diffusing 
 itself in our ovens and kneading-troughs, and availing itself 
 of the artificial warmth which we afford. It is well known 
 also that beetles, and many other kinds of ligniperdous 
 insects, have been introduced into Great Britain in timber ; 
 especially several North-American species. c The commercial 
 relations,' says Malte-Brun,f 'between France and India, 
 
 * Gloger, Aband. der Vogel, p. 103 ; Pallas, Zoog. Rosso-Asiat., torn. ii. p. 197. 
 f Syst. of Geog., vol. viii. p. 169. 
 
368 DIFFUSION OF TERRESTEIAL ANIMALS. [Cn. XXXIX. 
 
 have transported from the latter country the aphis, which 
 destroys the apple-tree, and two sorts of Neuroptera, the 
 Lucifuga and Flavicola, mostly confined to Provence and the 
 neighbourhood of Bordeaux, where they devour the timber 
 in the houses and naval arsenals. 
 
 Among mollusks we may mention the Teredo navalis, which 
 is a native of equatorial seas, but which, by adhering to the 
 bottom of ships, was transported to Holland, where it has 
 been most destructive to vessels and piles. The same species 
 has also become naturalised in England, and other countries 
 enjoying an extensive commerce. Bulimus undatus, a land 
 species of considerable size, native of Jamaica and other 
 West Indian islands, has been imported, adhering to tropical 
 timber, into Liverpool ; and, as Mr. Broderip informed me, 
 is now naturalised in the woods near that town. 
 
 In all these and innumerable other instances we may re- 
 gard the involuntary agency of man as strictly analogous to 
 that of the inferior animals. Like them, we unconsciously 
 contribute to extend or limit the geographical range and 
 numbers of certain species, in obedience to general rules in 
 the economy of nature, which are for the most part beyond 
 our control. 
 
3G9 
 
 CHAPTER XL. 
 
 ON THE GEOGRAPHICAL DISTRIBUTION AND MIGRATION OF 
 
 SPECIES continued. 
 
 GEOGRAPHICAL DISTRIBUTION AND MIGRATION OF FISH OF TESTACEA 
 
 OF INSECTS MOTHS SEEN FLYING 300 MILES FROM LAND BOTANICAL 
 
 GEOGRAPHY DISPERSION OF PLANTS AGENCY OF RIVERS AND CURRENTS 
 
 MARINE PLANTS SARGASSTJM OR GULF-WEED AGENCY OF ANIMALS IN THE 
 DISTRIBUTION OF PLANTS AGENCY OF MAN, BOTH VOLUNTARY AND INVOLUN- 
 TARY, IN THE DISPERSION OF PLANTS. 
 
 GEOGRAPHICAL DISTRIBUTION AND MIGRATION OF FISH. 
 
 Although we are less acquainted with the habitations of 
 marine animals than with those of terrestrial species, yet it 
 is well ascertained that their distribution is governed by the 
 same general laws. 
 
 On comparing the freshwater fish of Europe and North 
 America, Sir John Richardson remarks, that the only species 
 which is unequivocally common to the two continents is the 
 pike (Esox lucius) ; and it is curious that this fish is unknown 
 to the westward of the Rocky Mountains, the very coast which 
 approaches nearest to the old continent.* According to the 
 same author the genera of freshwater fish in China agree 
 closely with those of the peninsula of India, but the species 
 are not the same. c As in the distribution,' he adds, c of 
 marine fish, the interposition of a continent stretching from 
 the tropics far into the temperate or colder parts of the ocean, 
 separates different ichthyological groups ; so with respect to 
 the freshwater species, the intrusion of arms of the sea 
 running far to the northwards, or the interposition of a lofty 
 mountain-chain, effects the same thing. The freshwater 
 fish of the Cape of Good Hope and the South-American 
 ones, are different from those of India and China. 'f 
 
 Cuvier and Valenciennes, in their ' Histoire des Poissons,' 
 
 * Brit, Assoc. Keports, vol. v. p. 203. 
 f Report to the Brit. Assoc., 1845, p. 192. 
 VOL. II. B B 
 
370 GEOGRAPHICAL DISTRIBUTION AND [Cn. XL. 
 
 observe that very few species of marine fish cross the Atlantic. 
 But a great many species are common to the opposite sides of 
 the Indian Ocean, inhabiting alike the Red Sea, the eastern 
 coast of Africa, Madagascar, the Mauritius, the southern seas 
 of China, the Malay archipelago, the northern coasts of Aus- 
 tralia, and the whole of Polynesia ! * This very wide diffu- 
 sion, says Sir J. Richardson, may have been promoted by 
 chains of islands running east and west, which are wanting 
 in the deep Atlantic. An archipelago extending far in lon- 
 gitude, favours the migration of fish by multiplying the 
 places of deposit for spawn along the shores of islands, and 
 on intervening coral banks ; and in such places, also, fish 
 find their appropriate food. 
 
 Although the marine shells on the opposite side of the 
 Isthmus of Panama are scarcely any one of them the same, 
 yet nearly a third of the marine fishes, or 48 out of 158 
 species, have recently been ascertained by Dr. Giinther to be 
 common to the Pacific Ocean and Caribbean Sea. It has 
 been said in explanation of the species of Testacea being 
 distinct, that the coast on the east side of the isthmus is 
 low, and the sea shallow, whereas the west or Pacific coast 
 is abrupt with perpendicular cliffs. The fish would be 
 much more independent of the physical geography of the 
 coast, and their eggs might be transported from one side 
 of the isthmus to the other by birds. f 
 
 The flying fish are found (some stragglers excepted) only 
 between the tropics : in receding from the line, they never 
 approach a higher latitude than the fortieth parallel. The 
 course of the Gulf-stream, however, and the warmth of its 
 water, enable some tropical fish to extend their habitations 
 far into the temperate zone; thus the chsetodons, which 
 abound in the seas of hot climates, are found among the 
 Bermudas on the thirty-second parallel, where they are pre- 
 served in basins inclosed from the sea, as an important ar- 
 ticle of food for the garrison and inhabitants. Other fish, 
 following the direction of the same great current, range 
 from the coast of Brazil to the banks of Newfoundland. J 
 
 * Richardson, Brit. Assoc. Reports, 1867, p. 181. 
 
 1845, p. 190. t Sir J. Richardson, Brit. Assoc. 
 
 t Gardener's Chronicle, Feb. 23, Reports, 1845, p. 190. 
 
CH. XL.] MIGRATION OF SPECIES. 371 
 
 All are aware that there are certain fish of passage which 
 have their periodical migrations, like some tribes of birds. 
 The salmon, towards the season of spawning, ascends the 
 rivers for hundreds of miles, leaping up the cataracts which 
 it meets in its course, and then retreats again into the depths 
 of the ocean. The herring and the haddock, after frequenting 
 certain shores, in vast shoals, for a series of years, desert 
 them again, and resort to other stations, followed by the 
 species which prey on them. Eels are said to descend into 
 the sea for the purpose of producing their young, which are 
 seen returning into the fresh water by myriads, extremely 
 small in size, but possessing the power of surmounting every 
 obstacle which occurs in the course of a river, by applying 
 their slimy and glutinous bodies to the surface of rocks, or 
 the gates of a lock, even when dry, and so climbing over it.* 
 Before the year 1800 there were no eels in Lake Wener, the 
 largest inland lake in Sweden, which discharges its waters 
 by the celebrated cataracts of Trolhattan. But according to 
 Professor Nilsson, when a canal was opened uniting the river 
 Gotha with the lake by a series of nine locks, eels were ob- 
 served in abundance in the lake. It appears, therefore, that 
 though they were unable to ascend the falls, they made their 
 way. by the locks, by which in a very short space a difference 
 of level of 114 feet is overcome. 
 
 Gmelin says, that the Anseres (wild geese, ducks, and 
 others) subsist, in their migrations, on the spawn of fish ; 
 and that oftentimes, when they void the spawn, two or three 
 days afterwards, the eggs retain their vitality unimpaired. f 
 When there are many disconnected freshwater lakes in a 
 mountainous region, at various elevations, each remote from 
 the other, it has often been deemed inconceivable how they 
 could all become stocked with fish from one common source ; 
 but it has been suggested, that the minute eggs of these 
 animals may sometimes be entangled in the feathers of 
 waterfowl. These, when they alight to wash and plume 
 themselves in the water, may often unconsciously contribute 
 to propagate swarms of fish, which, in due season, will supply 
 them with food. Some of the water-beetles, also, as the 
 
 * Phil. Trans. 1747, p. 395. t Amcen. Acad., Essay 75. 
 
 B B 2 
 
372 GEOGRAPHICAL DISTRIBUTION AND [Cn.XL. 
 
 Dyticidse, are amphibious, and in the evening quit their lakes 
 and pools ; and, flying in the air, transport the minute ova 
 of fishes to distant waters. In this manner some naturalists 
 account for the fry of fish appearing occasionally in small 
 pools caused by heavy rains. 
 
 GEOGRAPHICAL DISTRIBUTION AND MIGRATIONS OF 
 TESTACEA. 
 
 The Testacea are a class of animals of peculiar importance 
 to the geologist ; because their remains are found in strata 
 of all ages, and generally in a higher state of preservation 
 than those of other organic beings. 
 
 Some forms are exclusively confined to warm, others to cold , 
 latitudes. Marine currents flowing permanently in certain 
 directions, and the influx at certain points of great bodies of 
 fresh water, limit the extension of many species. Those 
 which love deep water are arrested by shoals ; others, fitted 
 for shallow seas, cannot migrate across unfathomable abysses. 
 The nature also of the ground has an important influence on 
 the testaceous fauna, both on the land and beneath the waters. 
 Certain species prefer a sandy, others a gravelly, and some a 
 muddy sea-bottom. On the land, limestone is of all rocks 
 the most favourable to the number and propagation of species 
 of the genera Helix, Clausilia, Bulimus, and others. Pro- 
 fessor E. Forbes has shown, as the result of his labours in 
 dredging in the jiEgean Sea, that there are eight well-marked 
 regions of depth, each characterised by its peculiar testaceous 
 fauna. The first of these, called the littoral zone, extends 
 to a depth of two fathoms only ; but this narrow belt is 
 inhabited by more than 100 species. The second region, 
 of which ten fathoms is the inferior limit, is almost equally 
 populous ; and a copious list of species is given as charac- 
 teristic of each region down to the seventh, which lies be- 
 tween the depths of 80 and 105 fathoms, all the inhabited 
 space below this being included in the eighth province, where 
 110 less than 65 species of shell-fish or mollusca have been 
 taken. The majority of the shells in this lowest zone are 
 white or transparent. Only two species are common to 
 
CH. XL. MIGRATION OF TESTACEA. 373 
 
 all the eight regions, namely, Area lactea and Cerithium 
 lima.* 
 
 Great range of some provinces and species. In Europe coii- 
 chologists distinguish between the arctic fauna, the southern 
 boundary of which corresponds with the isothermal line of 
 32 F., and the Celtic, which, commencing with that limit as 
 its northern frontier, extends southwards to the mouth of the 
 English Channel and Cape Finisterre, in France. From that 
 point begins the Lusitanian fauna, which, according to the 
 observations of Mr. M'Andrew in 1852, ranges to the Canary 
 Islands. The Mediterranean province is distinct from all 
 those above enumerated, although it has some species in 
 common with each. 
 
 The Indo-Pacific region is by far the most extensive of all. 
 It reaches from the Eed Sea and the eastern coast of Africa, 
 to the Indian archipelago and adjoining parts of the Pacific 
 Ocean. To the geologist it furnishes a fact of no small 
 interest, by teaching us that one group of living species of 
 mollusca may prevail throughout an area exceeding in mag- 
 nitude the utmost limits we can as yet assign to any assem- 
 blage of contemporaneous fossil species. Mr. Cuming ob- 
 tained more than 100 species of shells from the eastern coast 
 of Africa identical with those collected by himself at the 
 Philippines and in the eastern coral islands of the Pacific 
 Ocean, a distance of 12,000 miles, equal, says Darwin, to that 
 from pole to pole. 
 
 Certain species of the genus lanthina have a very wide 
 range, being common to seas north and south of the equator. 
 They are all provided with a beautifully contrived float, which 
 renders them buoyant, facilitating their dispersion, and 
 enabling them to become active agents in disseminating other 
 species. Captain King took a specimen of lanthina fragilis 
 alive, a little north of the equator, so loaded with barnacles 
 (Pentelasmis) and their ova that the upper part of its shell was 
 invisible. 
 
 Helix putris (Succinea putris, Lam.) has a wide range in 
 Europe, occurs also in Siberia, and is said to inhabit New- 
 
 * Report to the Brit. Assoc. 1843, p. 130. 
 
 t Quart. Journ. Geol. Soc.. 1846, vol. ii. p. 268. 
 
374 GEOGRAPHICAL DISTRIBUTION AND [On. XL. 
 
 fbundland and parts of North America. It was found by 
 Captain Hutton in Afghanistan."* As this animal inhabits 
 constantly the borders of pools and streams where there is 
 much moisture, it is not impossible that different water- 
 fowl have been the agents of spreading some of its minute 
 eggs, which may have been entangled in their feathers. The 
 freshwater snail, Lymneus palustris, so abundant in English 
 ponds, ranges uninterruptedly from Europe to Cashmere, and 
 thence to the eastern part of Asia. Helix aspersa, one of 
 the commonest of our larger land-shells, is found in St. 
 Helena and other distant countries. Some conchologists have 
 conjectured that it was accidentally imported into St. Helena 
 in some ship ; for it is an eatable species. 
 
 As an illustration of the power of such mollusca to retain 
 life during a long voyage without air or nourishment, I may 
 mention that four individuals of a large species of land shell 
 (Bulimus), from Valparaiso, were brought to England by 
 Lieutenant Graves, who accompanied Captain King in his 
 expedition to the Straits of Magellan. They had been packed 
 up in a box, and enveloped in cotton : two for a space of 
 thirteen, one for seventeen, and a fourth for upwards of 
 twenty months : but when they were exposed by Mr. 
 Broderip to the warmth of a fire in London, and provided with 
 tepid water, I saw them revive and feed greedily on lettuce 
 leaves. 
 
 Perhaps no species has a better claim to be called cosmo- 
 polite than one of our British bivalves, Saxicava rugosa. It 
 is spread over all the north-polar seas, and ranges in one 
 direction through Europe to Senegal, occurring on both sides 
 of the Atlantic ; while in another it finds its way into the 
 North Pacific, and thence to the Indian Ocean. Nor do its 
 migrations cease till it reaches the Australian seas. 
 
 A British brachiopod, named Terebratula caput serpentis, is 
 common, according to Professor E. Forbes, to both sides of 
 the North Atlantic, and to the South-African and Chinese 
 seas. 
 
 Mode of diffusion of Testacea. Notwithstanding the pro- 
 
 * J. Gwyn Jeffreys, British Conchology, p. 152. 
 
CH. XL.] MIGRATION OF TESTACEA. 375 
 
 verbially slow motion of snails and mollusks in general, and 
 although many aquatic species adhere constantly to the same 
 rock for their whole lives, they are by no means destitute of 
 provision for disseminating themselves rapidly over a wide 
 area. ' Some Mollusca,' says Professor E. Forbes, c migrate 
 in their larva state, for all of them undergo a metamorphosis 
 either in the egg or out of the egg. The Gasteropoda com- 
 mence life under the form of a small spiral shell, and an 
 animal furnished with ciliated wings, or lobes, like a pteropod, 
 by means of which it can swim freely, and in this form can 
 migrate with ease through the sea.'* 
 
 We are accustomed to associate in our minds the idea of 
 the greatest locomotive powers with the most mature and 
 
 
 The young fry of a cockle (Cardium pygmamm), from Loven's Kougl. Vetenskaps 
 Akadem. Handling, 1848. 
 
 A. The young just hatched, magnified 100 its filamentous appendage b. 
 diameters. c. The rudimentary intestine. 
 
 B. The same farther advanced. d. The rudimentary shell. 
 a. The ciliated organ of locomotion with 
 
 perfect state of each species of invertebrate animal, especially 
 when they undergo a series of transformations ; but in all 
 the Mollusca the reverse is true. The young of the cockle, 
 for example (Cardium), possess, when young or in the larva 
 state, an apparatus which enables them both to swim and to 
 be carried along easily by a marine current. (See fig. 135.) 
 
 These small bodies here represented, which bear a con- 
 siderable resemblance to the fry of univalve, or gasteropodous 
 shells, above mentioned, are so minute at first as to be just 
 visible to the naked eye. They begin to move about from the 
 moment they are hatched, by means of the long cilia, a, a, 
 placed on the edges of the locomotive disk or velum. This 
 
 * Edin. New Phil. Journ. April, 1844. 
 
376 GEOGRAPHICAL DISTRIBUTION AND [On. XL. 
 
 disk shrinks up as they increase in size, and gradually dis- 
 appears, no trace of it being visible in the perfect animal. 
 
 Some species of shell-bearing Mollusca lay their eggs in a 
 sponge-like nidus, wherein the young remain enveloped for a 
 time after their birth ; and this buoyant substance floats far 
 and wide as readily as sea-weed. The young of other vivi- 
 parous tribes are often borne along entangled in sea-weed. 
 Sometimes they are so light, that, like grains of sand, they 
 can be easily moved by currents. Balani and Serpulse are 
 sometimes found adhering to floating cocoa-nuts, and even to 
 fragments of pumice far out at sea. It is probable, indeed, 
 that the porous and sponge-like texture of pumice causes it 
 to be a vehicle for the transport of eggs of mollusks and 
 insects and of the seeds of plants far more effective in many 
 regions than has been hitherto suspected. Mr. Bates saw 
 pieces, of it floating on the river Amazon 1,200 miles from its 
 source, the nearest volcanos of the Andes. He also observed 
 other fragments 900 miles lower down the river, which in the 
 rainy season are floated at the rate of from three to five miles 
 an hour.* They must often reach the sea, and be carried by 
 currents for hundreds of miles farther from their point of 
 departure. 
 
 In rivers and lakes, on the other hand, aquatic univalves 
 usually attach their eggs to leaves and sticks which have 
 fallen into the water, and which are liable to be swept away, 
 during floods, from tributaries to the main streams, and from 
 thence to all parts of the same basin. Particular species 
 may thus migrate during one season from the head waters 
 of the Mississippi, or any other great river, to countries bor- 
 dering the sea, at the distance of many thousand miles. An 
 illustration of the mode of attachment of these eggs will be 
 seen in the annexed cut (fig. 136). 
 
 A lobster (Astacus marinus) was taken alive covered with 
 living mussels (Mytilus edulis) ; f and a large female crab 
 (Cancer pagurus), covered with oysters, and bearing also 
 Anomia ephippium, and Actinise, was also taken in 1832, off 
 the English coast. The oysters, seven in number, included 
 
 * Naturalist of the Amazons, vol. ii. p. 170. 
 
 t The specimen is preserved in the Museum of the Zool. Soc. of London. 
 
CH. XL.] 
 
 MIGRATION OF INSECTS. 
 
 377 
 
 individuals of six years' growth, and the two largest were four 
 inches long and three inches and a half broad. * 
 
 From this example we learn the manner in which oysters 
 may be diffused over every part of the sea where the crab 
 
 Fig. 136. 
 
 /Iff. 2 
 
 Eggs of freshwater Mollusks. 
 
 Fig. 1. Eggs of Ampullaria ovata (a fluviatile a dead leaf lying under water, 
 
 species) fixed to a small sprig which had fallen Fig. 3. Eggs of the common Limneus (Z. 
 
 into the water. vulgaris) , adhering to a dead stick under water. 
 
 Fig. 2. Eggs of Planorbis albus, attached to 
 
 wanders ; and if they are at length carried to a spot where 
 there is nothing but fine mud, the foundation of a new oyster- 
 bank may be laid on the death of the crab. In this instance 
 the oysters survived the crab many days, and were killed at 
 last only by long exposure to the air. 
 
 GEOGRAPHICAL DISTRIBUTION AND MIGRATIONS OF INSECTS. 
 
 The entomological provinces coincide very closely with 
 those of the higher animals as already described. Few species 
 have a very wide range, but there are exceptions to this 
 rule, and among them may be mentioned our painted lady 
 butterfly (Vanessa cardui), which re-appears at the Cape 
 of Good Hope and in New Holland and Japan with scarcely 
 
 * Mr. Broderip observed that this 
 crab, which was apparently in per- 
 fect health, could not have cast her shell 
 fcr six years, whereas some naturalists 
 
 have stated that the species moults 
 annually, without limiting the moulting 
 period to the early stages of the growth 
 of the animal. 
 
S78 GEOGRAPHICAL DISTRIBUTION AND [On. XL. 
 
 a varying streak."* The same species is said to be one of 
 the few insects which are universally dispersed over the 
 earth, being found in Europe, Asia, Africa, America, and 
 Australia. Its wide range seems to imply a capacity enjoyed 
 by few species, of enduring a great diversity of tempera- 
 ture, and is the more interesting because of the migratory 
 instinct which it sometimes displays. 
 
 A vast swarm of this species, forming a column from ten 
 to fifteen feet broad, was, in 1826, observed in the Canton de 
 Vaud : they traversed the country with great rapidity from 
 north to south, all flying onwards in regular order, close 
 together, and not turning from their course on the approach 
 of other objects. Professor Bonelli, of Turin, observed, in 
 March of the same year, a similar swarm of the same species, 
 also directing their flight from north to south, in Piedmont, 
 in such immense numbers that at night the flowers were 
 literally covered with them. They, had been traced from 
 Coni, Eaconi, Susa, &c. A similar flight at the end of the 
 last century is recorded by M. Louch, in the Memoirs of the 
 Academy of Turin. The fact is the more worthy of notice, 
 because the caterpillars of this butterfly are not gregarious, 
 but solitary from the moment that they are hatched ; and 
 this instinct remains dormant, while generation after gene- 
 ration passes away, till it suddenly displays itself in full 
 energy when their numbers happen to be in excess. 
 
 The European hive-bee (Apis mettifica), although not a 
 native of the New World, is now established both in North 
 and South America. It was introduced into the United 
 States by some of the early settlers, and has since overspread 
 the vast forests of the interior, building hives in the decayed 
 trunks of trees. The Indians,' says Irving, ' consider them 
 as the harbinger of the white man, as the buffalo is of the 
 red man, and say that in proportion as the bee advances the 
 Indian and the buffalo retire. It is said,' continues the 
 same writer, c that the wild bee is seldom to be met with at 
 any great distance from the frontier, and that they have 
 always been the heralds of civilisation, preceding it as it 
 advanced from the Atlantic borders. Some of the ancient 
 
 * Kirby and Spence, vol. iv. p. 487; and other authors. 
 
CH. XL.] MIGRATION OF INSECTS. 379 
 
 settlers of the west even pretend to give the very year when 
 the honey-bee first crossed the Mississippi.* The same species 
 is now also naturalised in Van Diemen's Land and New 
 Zealand. 
 
 As almost all insects are winged, they can readily spread 
 themselves wherever their progress is not opposed by un- 
 congenial climates, or by seas, mountains, and other physical 
 impediments ; and these barriers they can sometimes sur- 
 mount by abandoning themselves to violent winds, which, as 
 I shall afterwards state when speaking of the dispersion of 
 seeds (p. 386), may in a few hours carry them to very consider- 
 able distances. On the Andes some sphinxes and flies have 
 been observed by Humboldt, at the height of 19,180 feet above 
 the sea, and which appeared to him to have been involuntarily 
 carried into these regions by ascending currents of air.f 
 
 Inundations of rivers, observes Kirby, if they happen at 
 any season except in the depth of winter, always carry down a 
 number of insects, floating on the surface of bits of stick, 
 weeds, &c. ; so that when the waters subside, the entomolo- 
 gist may generally reap a plentiful harvest. In the dissemi- 
 nation, moreover, of these minute beings, as in that of plants, 
 the larger animals play their part. Insects are, in number- 
 less instances, borne along in the coats of animals, or the 
 feathers of birds ; and the eggs of some species are capable, 
 like seeds, of resisting the digestive powers of the stomach, 
 and after they are swallowed with herbage, may be ejected 
 again unharmed in the dung. 
 
 White mentions a remarkable shower of aphides which 
 seem to have emigrated, with an east wind, from the great 
 hop plantations of Kent and Sussex, and blackened the 
 shrubs and vegetables where they alighted at Selborne, 
 spreading at the same time in great clouds all along the 
 vale from Farnham to Alton. These aphides are sometimes 
 accompanied by vast numbers of the common lady-bird 
 (Coccinella septempunctata) , which feed upon them.J 
 
 It is remarkable, says Kirby, that many of the insects 
 which are occasionally observed to emigrate, as, for instance, 
 
 * Washington Irving's Tour in the gions Malte-Brun, vol. v. p. 379. 
 Prairies, ch. ix. J Kirby and Spence, vol. ii. p. 9. 
 
 f Description of the Equatorial Ee- 1817. 
 
380 GEOGEAPHICAL DISTRIBUTION AND [Cn. XL. 
 
 the Libellulse, Coccinellee, Carabi, Cicadee, &c., are not 
 usually social insects ; but seem to congregate, like swallows, 
 merely for the purpose of emigration.* Here, therefore, we 
 have an example of an instinct developing itself on certain 
 rare emergencies, causing unsocial species to become gre- 
 garious and to venture sometimes even to cross the ocean. 
 
 The armies of locusts (Gryllus migratorius) , which darken 
 the air in Africa and traverse the globe from Turkey to our 
 southern counties in England, are well known to all, and their 
 vast geographical range will again be alluded to (Chap. XLII.) . 
 When the western gales sweep over the Pampas they bear 
 along with them myriads of insects of various kinds. As a 
 proof of the manner in which species may be thus diffused, I 
 may mention that when the Creole frigate was lying in the 
 outer roads off Buenos Ayres, in 1819, at the distance of 
 six miles from the land, her decks and rigging were suddenly 
 covered with thousands of flies and grains of sand. The 
 sides of the vessel had just received a fresh coat of paint, 
 to which the insects adhered in such numbers as to spot 
 and disfigure the vessel, and to render it necessary partially 
 to renew the paint.f The late Admiral W. H. Smyth was 
 obliged to repaint his vessel, the Adventure, in the Mediterra- 
 nean, from the same cause. He was on his way from Malta 
 to Tripoli, when a southern wind blowing from the coast of 
 Africa, then one hundred miles distant, drove such myriads 
 of flies upon the fresh paint, that not the smallest point was 
 left unoccupied by insects. 
 
 Moths seen flying 300 miles from land. Captain Henry 
 Toynbee has put on record some striking examples of the 
 great distance from land at which the larger Lepidoptera are 
 occasionally seen on the wing. A female of the large 
 Sphynx Convolvuli flew on board his ship, the Hotspur, East 
 Indiaman, inlat. 12 09' N. and long. 21 17' W., a point 300 
 miles from the nearest coast of Africa, and about 210 miles 
 from the Cape de Verde Islands, from which last it is 
 supposed to have come, as the prevailing winds at the time 
 were north-westerly. Two individuals of the common Death's 
 
 * Kirby and Spence, vol. ii. p. 9. t lam indebted to Lieutenant Graves, 
 
 1817. B.N. for this information. 
 
Cii.XL.] MIGRATION OF PLANTS. 381 
 
 Head Moth (Acherontia atropos) also flew on board the Hotspur 
 during the same homeward voyage, in lat. 40 29' N. long. 
 15 W., or 260 miles from the nearest land (the coast of 
 Portugal) after an easterly gale. They had already traversed 
 more than two-thirds of the distance from Europe to Madeira, 
 and the case affords a good illustration of the manner in 
 which islands far out at sea may be peopled with insects 
 from the nearest continents.* 
 
 To the southward of the river Plate, off Cape St. Antonio, 
 and at the distance of fifty miles from land, several large 
 dragon-flies alighted 011 the Adventure frigate, during 
 Captain King's expedition to the Straits of Magellan. If 
 the wind abates when insects are thus crossing the sea, 
 the most delicate species are not necessarily drowned ; for 
 many can repose without sinking on the water. The slender 
 long-legged Tipulse have been seen standing on the surface 
 of the sea, when driven out far from our coast, which took 
 wing immediately on being approached. f Exotic beetles are 
 sometimes thrown 011 our shore, which revive after having 
 been long drenched in salt water; and the periodical ap- 
 pearance of some conspicuous butterflies amongst us, after 
 being unseen some for five, others for fifty years, has been 
 ascribed, not without probability, to the agency of the winds. 
 
 BOTANICAL GEOGRAPHY. 
 
 Scarcely 1,400 species of plants appear to have been 
 known and described by the Greeks, Eomans, and Arabians. 
 At present, more than 3,000 species are enumerated as 
 natives of our own island. J In other parts of the world 
 there have been now collected more than 100,000 reputed 
 species, specimens of which are preserved in European her- 
 bariums. It was not to be supposed, therefore, that the 
 ancients should have acquired any correct notions respecting 
 what has been called the geography of plants, although 
 
 * Both the above-mentioned insects of my friend, the late Mr. John Curtis, 
 
 were shown at a meeting of the Zoo- the able entomologist, 
 logical Society by Mr. Flower, May 22, J Barton's Lectures on the Geography 
 
 1866. of Plants, p. 2. 1827. 
 
 t I state this fact on the authority 
 
382 GEOGEAPHICAL DISTRIBUTION AND [Cn. XL. 
 
 the influence of climate on the character of the vegetation 
 could hardly have escaped their observation. 
 
 Antecedently to investigation, there was no reason for 
 presuming that the vegetable productions, growing wild in 
 the eastern hemisphere, should be unlike those of the western, 
 in the same latitude ; nor that the plants of the Cape of 
 Good Hope should be unlike those of the south of Europe ; 
 situations where the climate is little dissimilar. The contrary 
 supposition would have seemed more probable, and we might 
 have anticipated an almost perfect identity in the plants 
 which inhabit corresponding parallels of latitude at equal 
 heights above the sea. The discovery, therefore, that each 
 separate region of the globe, both of the land and water, is 
 occupied, in the vegetable as well as in the animal world, by 
 distinct groups of species, and that most of the exceptions to 
 this general rule are referable to disseminating causes now 
 in operation, is eminently calculated to prepare us to receive 
 with favour any hypothesis respecting the first introduction 
 of species which may be reconcilable with such phenomena. 
 
 Botanical regions. Humboldt was among the first to pro- 
 mulgate philosophical views on the distinctness of the vegetable 
 productions of different regions of the globe. Every hemi- 
 sphere, he said, is inhabited by different species of plants, 
 and it is not by the diversity of clima,tes that we can attempt 
 to explain why equinoctial Africa has no Laurinese, and 
 the New World no Heaths ; * or why the Calceolarias are 
 found only in the southern hemisphere. 
 
 6 We can conceive/ he adds, ' that a small number of the 
 families of plants, for instance, the Musacese and the Palms, 
 cannot belong to very cold regions, on account of their in- 
 ternal structure and the importance of certain organs ; but 
 we cannot explain why no one of the Melastomas (a family 
 allied to the Myrtles) vegetates north of the parallel of 
 thirty degrees ; or why no rose-tree belongs to the southern 
 hemisphere. Analogy of climates is often found in the two 
 continents without identity of productions. 'f 
 
 * The common heath (Erica vulgaris, Massachusetts north of Boston ; but this 
 L.) has, since Humboldt wrote, been case is quite exceptional, 
 found growing wild in one spot in f Pers. Nar., vol. v. p. 180. 
 
CH. XL.] MIGRATION OF PLANTS. 383 
 
 The luminous essay of Auguste De Candolle on ' Botanical 
 Geography ' (1820) presents us with the fruits of his own 
 researches and those of Htimboldt, Brown, and other eminent 
 botanists, so arranged, that the principal phenomena of the 
 distribution of plants are exhibited in connection with the 
 causes to which they are supposed to be referable.* c lt 
 might not, perhaps, be difficult/ observes this writer, 'to find 
 two points, in the United Sta/fces and in Europe, or in equi- 
 noctial America and Africa, which present all the same 
 circumstances : as, for example, the same temperature, the 
 same height above the sea, a similar soil, an equal dose of 
 humidity ; yet nearly all, perhaps all, the plants in these two 
 similar localities shall be distinct. A certain degree of 
 analogy, indeed, of aspect, and even of structure, might very 
 possibly be discoverable between the plants of the two 
 localities in question ; but the species would in general be 
 different. Circumstances, therefore, different from those 
 which now determine the stations, have had an influence on 
 the habitations of plants.' 
 
 It may be as well to define in this place the technical sense 
 in which the words printed in italics are here used : station 
 indicates the peculiar nature of the locality where each species 
 is accustomed to grow, and has reference to climate, soil, 
 humidity, light, elevation above the sea, and other analogous 
 circumstances; whereas, by habitation is meant a general 
 indication of the country where a plant grows wild. Thus 
 the station of a plant may be a salt-marsh, a hill-side, the 
 bed of the sea, or a stagnant pool. Its habitation may be 
 Europe, North America, or New Holland, between the tropics. 
 The study of stations has been styled the topography, that 
 of habitations the geography, of botany. The terms thus 
 defined, express each a distinct class of ideas, which have 
 been often confounded together, and which are equally appli- 
 cable in zoology. 
 
 In farther illustration of the principle above alluded to, 
 that difference of longitude, independently of any influence 
 of temperature, is accompanied by a great, and sometimes a 
 
 * Essai Elementaire cle Geographie Botanique. Extrait du 18me vol. du Diet, 
 des Sci. Nat. 1820. 
 
384 GEOGRAPHICAL DISTRIBUTION AND [On. XL. 
 
 complete, diversity in the species of plants, De Candolle 
 observed, that, out of 2,891 species of phsenogamous plants 
 described by Pursh as known in 1*820 in the United States, 
 there were only 385 common to northern or temperate Europe. 
 
 On comparing New Holland with Europe, Mr. Brown as- 
 certained that, out of 4,100 species, then discovered in 
 Australia, there were only 166 common to Europe, and of 
 this small number there were some few which may have 
 been transported thither by man. Almost all of the 166 
 species were cryptogamic, and the rest consist, in nearly 
 every case, of phsenogamous plants which also inhabit in- 
 tervening regions. 
 
 But it is still more remarkable that there should be an 
 almost equal diversity of species, in distant parts of the 
 ancient continent between which there is an uninterrupted 
 land communication. Thus there is one assemblage of species 
 in China, another in the countries bordering the Black Sea 
 and the Caspian, a third in those surrounding the Mediter- 
 ranean, a fourth on the great platforms of Siberia and Tartary, 
 and so forth. 
 
 The distinctness of the groups of indigenous plants, in 
 the same parallel of latitude, is greatest, as in the case of 
 animals before mentioned, where continents are disjoined 
 by a wide expanse of ocean. In the northern hemisphere, 
 near the pole, where the extremities of Europe, Asia, and 
 America unite or approach near to one another, a consider- 
 able number of the same species of plants are found, common 
 to the three continents. But it has been remarked, that 
 these plants, which are thus so widely diffused in the arctic 
 regions, are also found in the chain of the Aleutian islands, 
 which stretch almost across from America to Asia, and which 
 may probably have served as the channel of communication 
 for the partial blending of the floras of the adjoining regions. 
 De Candolle enumerated twenty great botanical provinces, 
 inhabited by indigenous and aboriginal plants ; and his son 
 Alphonse, a distinguished living botanist, has made a further 
 subdivision into twenty-seven provinces, between which the 
 lines of demarcation are by no means ill-defined.* 
 
 * Alph. De Candolle, Monogr. des Campanulas. Paris, 1830. 
 
CH. XL.] MIGRATION OF PLANTS. 385 
 
 There are, however, not a few species which are common 
 to two or more than two of these provinces, and often repre- 
 sentative forms which some naturalists would class as mere 
 geographical varieties. The six ornithological divisions of 
 the globe before alluded to (p. 335), four of them in the Old 
 World and two in the New, are not on the whole inapplicable 
 to plants, if we wish to take a more large and comprehensive 
 view of the leading features in their geographical distribution, 
 especially as regards genera and families. 
 
 This holds true, particularly of the Neoarctic and Neo- 
 tropical regions, each of which contains a distinct assem- 
 blage of peculiar vegetable forms. Those of the table-land 
 of Brazil, which has an elevation of from 2,000 to 4,000 feet, 
 are described by Sir Charles Bunbury, after he had explored 
 the district, as belonging for the most part to generic types, 
 little known except to botanists, for they have not been 
 cultivated in Europe. But when he descended from the 
 Brazilian uplands towards the south, or to the grassy plains 
 of Uruguay and La Plata, he found plants still belonging to 
 the predominant South- American types, though represented 
 by different and local species. Such affinity between the 
 specific forms proper to the more elevated and to the lower 
 stations agrees well with the idea of certain original types 
 having been gradually adapted by variation and natural 
 selection to all the diversified conditions of the surface of the 
 land. 
 
 The Pampas and banks of the Plata are also remarkable 
 for the extraordinary manner in which some foreign European 
 plants, especially the thistles and trefoils, have overpowered 
 the indigenous vegetation.* The intruders have been intro- 
 duced by man sometimes unintentionally, and, having na- 
 turalised themselves, have become more conspicuous than any 
 of the native products of the soil. They illustrate a principle 
 before laid down, that the organic beings of each great region 
 which man finds in possession of wide areas are not those 
 which are most fitted of all contemporary species to flourish 
 there to the exclusion of all others. They appear to be 
 
 * Sir C. Bunbury, ' Characters of S. American Vegetation,' Fraser's Magazine, 
 July, 1867. 
 
 VOL. II. C C 
 
386 GEOGRAPHICAL DISTRIBUTION AND [Cn. XL. 
 
 simply the modified descendants of such an older fauna and 
 flora as happened to preexist under a somewhat different 
 phase of the earth's physical geography, or they are the 
 offspring of colonists which by natural means were able to 
 reach those lands. But the same organisms are powerless 
 to maintain their ground in the struggle for life if brought 
 into competition with species from distant regions which 
 would never without the aid of man have come into contact 
 with them. 
 
 Marine plants. The vegetation of the sea, like that of the 
 land, is divisible into different provinces each inhabited by 
 distinct species, but these provinces are fewer in number 
 because the temperature of the ocean is more uniform than 
 that of the atmosphere, and because the area of land bears a 
 small proportion to that of water, so that the migration of 
 marine plants is not so often stopped by barriers of land as is 
 that of the terrestrial species of the ocean. It is a remark- 
 able fact that Dr. Hooker has been able to identify no less 
 than a fifth part of the antarctic Algae, excluding the New 
 Zealand and Tasmanian groups, with British species. Yet 
 there is a much smaller proportion of cosmopolite species 
 among the Algse than among the terrestrial cellular crypto- 
 gams, such as lichens, mosses, and Hepaticse. 
 
 Dispersion of plants. The fact last alluded to, of the ubi- 
 quitous character of cryptogamous plants, deserves special 
 attention. Linnseus observed that, as the germs of plants of 
 this class, such as mosses, fungi, and lichens, consist of an 
 impalpable powder, the particles of which are scarcely visible 
 to the naked eye, there is no difficulty in accounting for their 
 being dispersed throughout the atmosphere, and carried to 
 every point of the globe, where there is a station fitted for 
 them. Lichens in particular ascend to great elevations, 
 sometimes growing on bare rocks two thousand feet above 
 the line of perpetual snow, where the mean temperature is 
 nearly at the freezing point. This elevated position must 
 contribute greatly to facilitate the dispersion of those buoy- 
 ant particles of which their fructification consists."* 
 
 * Linn., Tour in Lapland, vol. ii. p. 282. 
 
CH. XL.] MIGRATION OF PLANTS. 387 
 
 Some have inferred, from the springing up of mushrooms 
 whenever particular soils and decomposed organic matter are 
 mixed together, that the production of fungi is accidental, 
 and not analogous to that of perfect plants. But Fries, 
 whose authority on these questions is entitled to the highest 
 respect, has shown the fallacy of this argument in favour of 
 the old doctrine of equivocal generation. ' The sporules of 
 fungi,' says this naturalist, c are so infinite, that in a single 
 individual of Eeticularia maxima, I have counted above ten 
 millions, and so subtile as to be scarcely visible, often resem- 
 bling thin smoke ; so light that they may be raised perhaps 
 by evaporation into the atmosphere, and. dispersed in so 
 many ways by the attraction of the sun, by insects, wind, 
 elasticity, adhesion, &c., that it is difficult to conceive a 
 place from which they may be excluded.' * 
 
 The club-moss called Lycopodium cernuum affords a strik- 
 ing example of a cryptogamous plant universally distributed 
 over all equinoctial countries. It scarcely ever passes be- 
 yond the northern tropic, except in one instance, where it 
 appears around the hot-springs in the Azores, although it is 
 neither an inhabitant of the Canaries nor of Madeira. Doubt- 
 less its microscopic sporules are everywhere present, ready 
 to germinate on any spot where they can enjoy throughout 
 the year the proper quantity of warmth, moisture, light, and 
 other conditions essential to the species. 
 
 Almost every lichen brought home from the southern 
 hemisphere by the antarctic expedition under Sir James 
 Eoss, amounting to no less than 200 species, was ascer- 
 tained to be also an inhabitant of the northern hemisphere, 
 and almost all of them European. 
 
 When we contrast the cosmopolite character of this class 
 of plants with the comparatively limited range of most of the 
 phsenogamous species, we cannot fail to perceive how inti- 
 mately the geographical distribution of each is related to 
 their powers of dispersion. But, in order to see a con- 
 nection between these phenomena, we must first assume that 
 each species has one birthplace, and that it has radiated 
 
 * Fries, cited by Lindley, Introd. to Nat. Syst. of Botany. 
 C c 2 
 
388 GEOGKAPHICAL DISTRIBUTION AND [Cn. XL. 
 
 in all directions in which it is possible for it to spread from 
 the original point or centre where it was first formed. 
 
 The most active of the inanimate agents provided by na- 
 ture for scattering the seeds of plants over the globe, are 
 the movements of the atmosphere and of the ocean, and the 
 constant flow of water from the mountains to the sea. To 
 begin with the winds : a great number of seeds are furnished 
 with downy and feathery appendages, enabling them, when 
 ripe, to float in the air, and to be wafted easily to great dis- 
 tances by the most gentle breeze. Other plants are fitted 
 for dispersion by means of an attached wing, as in the case 
 of the fir-tree, so that they are caught up by the wind as 
 they fall from the cone, and are carried to a distance. 
 Amongst the comparatively small number of plants known 
 to Linnseus, no less than 138 genera are enumerated as 
 having winged seeds. 
 
 As winds often prevail for days, weeks, or even months to- 
 gether, in the same direction, these means of transportation 
 may sometimes be without limits ; and even the heavier grains 
 may be borne through considerable spaces, in a very short 
 time, during ordinary tempests ; for strong gales, which can 
 sweep along grains of sand, often move at the rate of about 
 forty miles an hour, and if the storm be very violent, at the 
 rate of fifty-six miles.* The hurricanes of tropical regions, 
 which root up trees and throw down buildings, sweep along 
 at the rate of ninety miles an hour ; so that, for however 
 short a time they prevail, they may carry even the heavier 
 fruits and seeds over friths and seas of considerable width, 
 and doubtless are often the means of introducing into islands 
 the vegetation of adjoining continents. Whirlwinds are also 
 instrumental in bearing along heavy vegetable substances 
 to considerable distances. Slight ones may frequently be ob- 
 served in our fields, in summer, carrying up haycocks into 
 the air, and then letting fall small tufts of hay far and wide 
 over the country ; but they are sometimes so powerful as to 
 dry up lakes and ponds, and to break off the boughs of trees, 
 and carry them up in a whirling column of air. 
 
 * Annuaire du Bureau des Longitudes. 
 
CH. XL.] MIGRATION OF SPECIES. 389 
 
 Dr. Franklin tells us, in one of his letters, that he saw, in 
 Maryland, a whirlwind which began by taking up the dust 
 which lay in the road, in the form of a sugar-loaf with the 
 pointed end downwards, and soon after grew to the height 
 of forty or fifty feet, being twenty or thirty in diameter. It 
 advanced in a direction contrary to the wind ; and although 
 the rotatory motion of the column was surprisingly rapid, 
 its onward progress was sufficiently slow to allow a man to 
 keep pace with it on foot. Franklin followed it on horse- 
 back, accompanied by his son, for three quarters of a mile, 
 and saw it enter a wood, where it twisted and turned round 
 large trees with surprising, force. These were carried up in 
 a spiral line, and were seen flying in the air, together with 
 boughs and innumerable leaves, which, from their height, ap- 
 peared reduced to the apparent size of flies. As this cause 
 operates at different intervals of time throughout a great 
 portion of the earth's surface, it may be the means of bear- 
 ing not only plants but insects, land testacea and their eggs, 
 with many other species of animals, to points which they 
 could never otherwise have reached, and from which they 
 may then begin to propagate themselves again as from a 
 new centre. 
 
 Agency of rivers and currents. In considering, in the 
 next place, the instrumentality of the aqueous agents of dis- 
 persion, I cannot do better than cite the words of one of 
 our ablest botanical writers. ' The mountain stream or 
 torrent,' observes Keith, ' washes down to the valley the seeds 
 which may accidentally fall into it, or which it may happen 
 to sweep from its banks when it suddenly overflows them. 
 The broad and majestic river, winding along the extensive 
 plain, and traversing the continents of the world, conveys to 
 the distance of many hundreds of miles the seeds that may 
 have vegetated at its source. Thus the southern shores of 
 the Baltic are visited by seeds which grew in the interior of 
 Germany, and the western shores of the Atlantic by seeds 
 that have been generated in the interior of America.'* Fruits, 
 moreover, indigenous to America and the West Indies, such 
 
 * System of Physiological Botany, yol. ii. p. 405. 
 
390 GEOGRAPHICAL DISTRIBUTION AND [On. XL. 
 
 as that of the Mimosa scandens, the cashew-nut, and others, 
 have been known to be drifted across the Atlantic by the Gulf- 
 stream, on the western coasts of Europe, in such a state that 
 they might have vegetated had the climate and soil been 
 favourable. Among these the Guilandina Bonduc, a legu- 
 minous plant, is particularly mentioned, as having been raised 
 from a seed found on the west coast of Ireland.* 
 
 Sir Hans Sloane states, that several kinds of beans cast 
 ashore on the Orkney Isles, and Ireland, but none of which 
 appear to have naturalised themselves, are derived from trees 
 which grow in the West Indies, and many of them in Jamaica, 
 lie conjectures that they might have been conve} 7 ed by rivers 
 into the sea, and then by the Gulf-stream, to greater distances. 
 
 The absence of liquid matter in the composition of seeds 
 renders them comparatively insensible to heat and cold, so 
 that they may be carried without detriment through climates 
 where the plants themselves would instantly perish. Such 
 is their power of resisting the effects of heat, that Spal- 
 lanzani mentions some seeds that germinated after having 
 been boiled in water, f Sir John Herschel informs me that 
 he has sown at the Cape of Good Hope the seeds of the 
 Acacia lophanta after they had remained for twelve hours in 
 water of 140 Fahrenheit, and they germinated far more 
 rapidly than unboiled seeds. He also states that an emi- 
 nent botanist, Baron Ludwig, could not get the seeds of a 
 species of cedar to grow at the Cape till they were thoroughly 
 boiled. 
 
 When, therefore, a strong gale, after blowing violently off 
 the land for a time, dies away, and the seeds alight upon the 
 surface of the waters, or wherever the ocean, by eating away 
 the sea-cliffs, throws down into its waves plants which would 
 never -otherwise reach the shores, the tides and currents 
 become active instruments in assisting the dissemination of 
 various classes of the vegetable kingdom. The pandanus and 
 many other plants have been distributed in this way over the 
 islands of the Pacific. 
 
 In a collection of 600 plants from the neighbourhood 
 
 * Brown, Append, to Tuckey, Nc. v. f System of Physiological Botany, 
 
 p. 481. vol. ii. p. 403. 
 
CH. XL.] MIGKATION OF SPECIES. 301 
 
 of the river Zaire, in Africa, the late Dr. Eobert Brown 
 found that thirteen species were also met with on the oppo- 
 site shores of Guiana and Brazil. He remarked that most 
 of these plants were found only on the lower parts of the 
 river Zaire, and were chiefly such as produced seeds capable 
 of retaining their vitality a long time in the currents of the 
 ocean. Dr. J. Hooker informs me that after an examination 
 of a great many insular floras, he has found that no one of 
 the large natural orders is so rich in species common to other 
 countries, as the Leguminosse. The seeds in this order, 
 which comprises the largest proportion of widely diffused 
 littoral species, are better adapted than those of any other 
 plants for water-carriage. 
 
 Mr. Darwin has made a series of experiments to ascertain 
 the number of days for which the seeds and fruits of various 
 plants could be immersed in salt water without injury, and 
 he found that out of 87 kinds, 64 germinated after they had 
 been 28 days in salt-water, and some survived an immersion 
 of 37 days. According to the average rate at which oceanic 
 currents run, he came to the conclusion that a large number 
 of seeds might be carried uninjured for nearly 1,000 miles 
 across the sea.* 
 
 Currents and winds in the arctic regions drift along ice- 
 bergs covered with an alluvial soil, on which pine-saplings 
 and a variety of herbaceous plants are seen growing, all of 
 which may continue to vegetate on some distant shore where 
 the ice-island may be stranded. 
 
 Dispersion of marine plants. With respect to marine ve- 
 getation, the seeds, being in their native element, may remain 
 immersed in water without injury for indefinite periods, so 
 that there is no difficulty in conceiving the diffusion of species 
 wherever uncongenial climates, contrary currents, and other 
 causes do not interfere. All are familiar with the sight of 
 the floating sea-weed ; 
 
 Flung from the rock on ocean's foam to sail, 
 
 Where'er the surge may sweep, the tempest's breath prevail. 
 
 I have before called attention (p. 386) to the interesting 
 fact that one-fifth of all the algse found in the antarctic 
 regions in 1841-3, by Dr. J. Hooker, were of species common 
 
 * Origin of Species, chap. xi. 
 
392 GEOGKAPHICAL DISTRIBUTION AND [Cn. XL. 
 
 to the British seas. He has suggested that cold currents 
 which prevail from Cape Horn to the equator, and are there 
 met by other cold waters, may by their direct influence, as 
 well as by their temperature, facilitate the passage of ant- 
 arctic species to the Arctic Ocean. 
 
 Remarkable accumulations of that species of sea-weed 
 generally known as gulf-weed, or sargassum, occur north of 
 the equator in the Northern Atlantic. Columbus and other 
 navigators, who first encountered these banks of algse, com- 
 pared them to vast inundated meadows, and stated that they 
 retarded the progress of their vessels. This mass of floating 
 vegetation, exceeding the British Isles in area, lies between 
 latitudes 20 and 35 to the south-west of Europe. 
 
 Sir Hans Sloane stated in 1696 that this weed grows on the 
 rocks about Jamaica, and is known to be ' carried by the 
 winds and current towards the coast of Florida and thence 
 into the North-American ocean, where it lies very thick on 
 the surface of the sea.' * 
 
 Humboldt first suggested that it occupies an eddy in that 
 part of the Atlantic where the Gulf-stream is met by the 
 current from the north ; and Maury gives a similar explana- 
 tion of another large bank of kelp and drift- weed in the 
 North Pacific, to the northward of the Sandwich Islands, 
 and of another in the Southern Ocean around Kerguelen's 
 Land between lat. 40 and 54.f 
 
 The late Robert Brown inclined to the opinion that the 
 original source of the gulf- weed might be some parts of the 
 coasts of the Gulf of Florida. When floating on the ocean 
 it propagates itself rapidly by new fronds which are contin- 
 ually pushed out from the old ones ; and the larger portion of 
 it being produced under such peculiar circumstances, the 
 plant may perhaps become so modified as not to be easily 
 identifiable with the original stock from which it is derived. J 
 The late Edward Forbes conceived that this weed first grew 
 on an old coast-line since submerged ; this coast having 
 
 * Phil. Trans. 1696. J K. Brown, Mode of Propagation of 
 
 f See map of Sargassum seas, taken Gulf-weed, Miscell. Works, vol. i. Kay 
 
 from Maury by Andrew Murray, Geog. Society, 1866. 
 
 Dist. of Mammals, 1866. 
 
CH. XL.] MIGRATION OF SPECIES. 393 
 
 formed the western extremity of the continent of Europe and 
 Northern Africa, which then extended far into the Atlantic.* 
 But the great depth of the ocean, ranging from 1,000 to 
 10,000 feet, and often of still greater depth, which prevails over 
 a great part of the area assumed by this hypothesis to have 
 been turned from land into sea, since the Miocene epoch, 
 makes me consider it far more probable that, instead of 
 growing on a bank which has sunk down, the gulf-weed has 
 been drifted from some part of America. 
 
 As proof of the extent to which sea- weed is drifted, I may 
 mention that along the northern edge of the Gulf-stream Dr. 
 Hooker found Fucus nodosus and F. serratus, which he traced 
 all the way from lat. 36 N". to England. The hollow pod- 
 like receptacles in which the seeds of many algae are lodged, 
 and the filaments attached to the seed-vessels of others, seem 
 intended to give buoyancy. It may also be remarked that 
 these hydrophytes are in general proliferous, so that the 
 smallest fragment of a branch can be developed into a per- 
 fect plant. The seeds, moreover, of the greater number of 
 species are enveloped with a mucous matter like that which 
 surrounds the eggs of some fish, and which not only protects 
 them from injury, but serves to attach them to floating bodies 
 or to rocks. 
 
 Agency of animals in the distribution of plants. But we 
 have as yet considered part only of the fertile resources of 
 nature for conveying seeds to a distance from their place of 
 growth. The various tribes of animals are busily engaged 
 in furthering an object whence they derive such important 
 advantages. Sometimes an express provision is found in the 
 structure of seeds to enable them to adhere firmly by prickles, 
 hooks, and hairs to the coats of animals, or feathers of the 
 winged tribe, to which they remain attached for weeks, or 
 even months, and are borne along into every region whither 
 birds or quadrupeds may migrate. Linnaeus enumerates 
 fifty genera of plants, and the number now known to botanists 
 is much greater, which are armed with hooks, by which, when 
 ripe, they adhere to the coats of animals. Most of these 
 vegetables, he remarks, require a soil enriched with dung. 
 
 * E. Forbes, Fauna and Flora, &c., 1846, vol. i. p. 349. 
 
394 GEOGRAPHICAL DISTRIBUTION AND [Cn. XL. 
 
 Few have failed to mark the locks of wool hanging on the 
 thorn-bushes, wherever the sheep pass, and it is probable that 
 the wolf or lion never give chase to herbivorous animals 
 without being unconsciously subservient to this part of the 
 vegetable economy. 
 
 A deer has strayed from the herd when browsing on some 
 rich pasture, when he is suddenly alarmed by the approach 
 of his foe. He instantly takes to flight, dashing through 
 many a thicket, and swimming across many a river and lake. 
 The seeds of the herbs and shrubs which have adhered to his 
 smoking flanks, and even many a thorny spray, which has 
 been torn off, and has fixed itself in his hairy coat, are 
 brushed off again in other thickets and copses. Even on the 
 spot where the victim is devoured many of the seeds which 
 he had swallowed immediately before the chase may be left 
 on the ground uninjured, and ready to spring up in a new 
 soil. 
 
 The passage, indeed, of undigested seeds through the 
 stomachs of animals is one of the most efficient causes of the 
 dissemination of plants, and is, of all others, perhaps the most 
 likely to be overlooked. Few are ignorant that a portion of 
 the oats eaten by a horse preserve their germinating faculty 
 in the dung. The fact of their being still nutritious is not 
 lost on the sagacious rook. To many, says Linnseus, it seems 
 extraordinary, and something of a prodigy, that when a field 
 is well tilled and sown with the best wheat, it frequently 
 produces darnel or the wild oat, especially if it be manured 
 with new dung ; they do not consider that the fertility of 
 the smaller seeds is not destroyed in the stomachs of 
 animals.* 
 
 Some birds of the order Passeres devour the seeds of plants 
 in great quantities, which they eject again in very distant 
 places, without destroying its faculty of vegetation : thus a 
 flight of larks will fill the cleanest field with a great quantity 
 of various kinds of plants, as the melilot trefoil (Medicago 
 lupulina), and others whose seeds are so heavy that the 
 wind is not able to scatter them to any distance. f In like 
 
 * Linnaeus, Amcen. Acad., vol. ii. f Amcen. Acad., vol. iv. Essay 75. 
 
 p. 409. 8. 
 
CH. XL.] MIGRATION OF SPECIES. 395 
 
 manner, the blackbird and misselthrush, when they devour 
 berries in too great quantities, are known to consign them 
 to the earth undigested in their excrement .~* 
 
 Pulpy fruits serve quadrupeds and birds as food, while 
 their seeds, often hard and indigestible, pass uninjured 
 through the intestines, and are deposited far from their 
 original place of growth in a condition peculiarly fit for 
 vegetation, f So well are the farmers, in some parts of 
 England, aware of this fact, that when they desire to raise a 
 quickset hedge in the shortest possible time, they feed 
 turkeys with the haws of the common white-thorn (Cratcegus 
 Oxyacantha), and then sow the stones which are ejected 
 in their excrement, whereby they gain an entire year in the 
 growth of the plant. J Birds, when they pluck cherries, sloes, 
 and haws, fly away with them to some convenient place ; 
 and when they have devoured the fruit, drop the stone into 
 the ground. Captain Cook, in his account of the volcanic 
 island of Tanna, one of the ISTew Hebrides, which he visited 
 in his second voyage, makes the following interesting obser- 
 vation : Mr. Forster, in his botanical excursion this day, 
 shot a pigeon, in the craw of which was a wild nutmeg. ' 
 It is easy, therefore, to perceive, that birds in their migra- 
 tions to great distances, and even across seas, may transport 
 even heavy seeds to new isles and continents. 
 
 The sudden deaths to which great numbers of frugivorous 
 birds are annually exposed must not be omitted as auxiliary 
 to the transportation of seeds to new habitations. When 
 the sea retires from the shore, and leaves fruits and seeds on 
 the beach, or in the mud of estuaries, it might, by the 
 returning tide, wash them away again, or destroy them by 
 long immersion ; but when they are gathered by land birds 
 which frequent the sea-side, or by waders and water-fowl, 
 they are often borne inland ; and if the bird to whose crop 
 they have been consigned is killed, they may be left to grow 
 up from the sea. Let such an accident happen but once 
 
 * Amosn. Acad., vol. vi. 22. to me by Professor Henslow, of Cam- 
 
 f Smith's Introd. to Phys. and Syst. bridge. 
 Botany, p. 304. 1807. Book iii. ch. iv. 
 
 J This information \vas communicated 
 
396 GEOGRAPHICAL DISTRIBUTION AND [Cn. XL. 
 
 in a century, or a thousand years, it will be sufficient to 
 spread many of the plants from one continent to another ; for 
 in estimating the activity of these causes, we must not consider 
 whether they act slowly in relation to the period of our obser- 
 vation, but in reference to the duration of species in general. 
 
 Let us trace the operation of this cause in connection with 
 others. A tempestuous wind bears the seeds of a plant 
 many miles through the air, and then delivers them to the 
 ocean ; the oceanic current drifts them to a distant continent ; 
 by the fall of the tide they become the food of numerous 
 birds, and one of these is seized by a hawk or eagle, which, 
 soaring across hill and dale to a place of retreat, leaves, after 
 devouring its prey, the unpalatable seeds to spring up and 
 flourish in a new soil. 
 
 Mr. Darwin found that fresh-water fish eat the seeds of many 
 land and water plants, and as the same fish are often devoured 
 by birds, such seeds may be readily transported by them to 
 great distances. The same naturalist observed also that the 
 earth adhering to the feet of birds, often contains a variety 
 of seeds of plants ; and he mentions one case where from a 
 ball of earth taken from the leg of a partridge he raised more 
 than 80 individual plants belonging to species both of 
 monocotyledons and dicotyledons.* Insects are probably in- 
 strumental like birds in disseminating plants, for proofs have 
 lately been obtained (see Chapter XLI.) of the germinating 
 power of seeds swallowed by locusts and rejected in their dung. 
 
 The machinery above adverted to, is so capable of dissemi- 
 nating seeds over almost unbounded spaces, that were we 
 more intimately acquainted with the economy of nature, we 
 might probably explain nearly all the instances of plants 
 inhabiting two points very remote from each other and not 
 found in places intermediate ; but some difficulties must 
 remain in accounting for the range of species so long as the 
 botanist confines his speculations to the present state of the 
 earth's physical geography and climate. For the geologist 
 can show that great changes have taken place in the height 
 of the land and in the position of land and sea since the 
 
 Origin of Species, 4th edition, p. 432. 
 
CH. XL.] MIGRATION OF SPECIES. 397 
 
 greater number of the living species of plants came into 
 being. And we shall see in the Forty- second Chapter how 
 much the rarity, or even the entire extinction, of species is 
 promoted by these changes. 
 
 Agency of man in the dispersion of plants. But in addition 
 to all the agents already enumerated as instrumental in 
 diffusing plants over the globe, we have still to consider man 
 one of the most important of all. He transports with him, 
 into every region, the vegetables which he cultivates for his 
 wants, and is the involuntary means of spreading a still 
 greater number which are useless to him, or even noxious. 
 
 * When the introduction of cultivated plants,' says De Candolle, 
 ' is of recent date, there is no difficulty in tracing their origin ; 
 but when it is of high antiquity, we are often ignorant of 
 the true country of the plants -on which we feed. No one 
 contests the American origin of the maize or the potato ; nor 
 the origin, in the Old World, of the coffee-tree, and of wheat. 
 But there are certain objects of culture, of very ancient 
 date, between the tropics, such for example as the banana, 
 of which the origin cannot be verified. Armies, in modern 
 times, have been known to carry, in all directions, grain and 
 cultivated vegetables from one extremity of Europe to the 
 other ; and thus have shown us how, in more ancient times, 
 the conquests of Alexander, the distant expeditions of the 
 Romans, and afterwards the crusades, may have transported 
 many plants from one part of the world to the other. '* 
 
 But, besides the plants used in agriculture, the number 
 which have been naturalised by accident, or which man 
 has spread unintentionally, is considerable. One of our old 
 authors, Josselyn, gives a catalogue of such plants as had, in 
 his time, sprung up in the colony since the English planted 
 and kept cattle in New England. They were two-and-twenty 
 in number. The common nettle was the first which the 
 settlers noticed ; and the plantain was called by the Indians 
 
 * Englishman's foot,' as if it sprung from their footsteps.f 
 
 6 We have introduced every where,' observes De Candolle, 
 
 * some weeds which grow among our various kinds of wheat, 
 
 * De Candolle, Essai Elemen. &c. t Quarterly Review, vol. xxx. p. 8. 
 p. 50. 
 
398 GEOGRAPHICAL DISTRIBUTION AND [On. XL. 
 
 and which have been received, perhaps, originally from Asia 
 along with them. Thus, together with the Barbary wheat, 
 the inhabitants of the south of Europe have sown, for many 
 ages, the plants of Algiers and Tunis. With the wools and 
 cottons of the East, or of Barbary, there are often brought 
 into France the grains of exotic plants, some of which 
 naturalise themselves. Of this I will cite a striking example. 
 There is, at the gate of Montpellier, a meadow set apart for 
 drying foreign wool, after it has been washed. There hardly 
 passes a year without foreign plants being found naturalised 
 in this drying-ground. I have gathered there Centaurea 
 parviflora, Psoralea palcestina, and Hypericum crispum.' This 
 fact is not only illustrative of the aid which man lends 
 inadvertently to the propagation of plants, but it also demon- 
 strates the multiplicity of seeds which are borne about in the 
 woolly and hairy coats of wild animals. 
 
 The same botanist mentions instances of plants naturalised 
 in seaports by the ballast of ships ; and several examples of 
 others which have spread through Europe from botanical 
 gardens, so as to have become more common than many 
 indigenous species. 
 
 It is scarcely a century, says Linnseus, since the Canadian 
 Erigeron, or flea-bane, was brought from America to the 
 botanical garden at Paris ; and already the seeds have been 
 carried by the winds so that it is diffused over France, the 
 British Islands, Italy, Sicily, Holland, and Germany.* Several 
 others are mentioned by the Swedish naturalist, as having 
 been dispersed by similar means. The common thorn-apple 
 (Datura Stramonium), observes Willdenow, now grows as a 
 noxious weed throughout all Europe, with the exception of 
 Sweden, Lapland, and Russia. It came from the East Indies 
 and Abyssinia to us, and was thus universally spread by 
 certain quacks, who used its seeds as an emetic. f The same 
 plant is now abundant throughout the greater part of the 
 United States, along road-sides and about farm-yards. The 
 yellow monkey-flower, Mimulus luteus, a plant from the north- 
 
 * Essay on the Habitable Earth, f Principles of Botany, p. 389. 
 
 Amoen. Acad., vol. ii. p. 409. 
 
CH. XL.] MIGRATION OF SPECIES. 399 
 
 west region of America, has now established itself in various 
 parts of England, and is spreading rapidly. 
 
 In hot and ill-cultivated countries, such naturalisations 
 take place more easily. Thus the Chenopodium ambrosioides, 
 sown by Mr. Burchell on a point of St. Helena, multiplied so 
 fast in four years as to become one of the commonest weeds 
 in the island, and it has maintained its ground ever since 
 1845.* 
 
 The most remarkable proof, says De Candolle, of the extent 
 to which man is unconsciously the instrument of dispersing 
 and naturalising species, is found in the fact, that in New 
 Holland, America, and the Cape of Good Hope, the European 
 species exceed in number all the others which have come from, 
 any distant regions ; so that, in this instance, the influence of 
 man has surpassed that of all the other causes which tend to 
 disperse plants over remote regions. About a fifth of the 
 British flowering plants are supposed to be naturalised 
 species, and a large proportion of them would perish with the 
 discontinuance of agriculture. 
 
 Although we are but slightly acquainted, as yet, with the 
 extent of our instrumentality in naturalising species, yet the 
 facts ascertained afford no small reason to suspect that the 
 number which we introduce unintentionally exceeds all those 
 transported by design. Nor is it unnatural to suppose that 
 the functions, which the inferior beings extirpated by man 
 once discharged in the economy of nature, should devolve 
 upon the human race. If we drive many birds of passage 
 from different countries, we are probably required to fulfil their 
 office of carrying seeds, eggs of fish, insects, mollusks, and 
 other creatures, to distant regions : if we extirpate quadrupeds, 
 we must replace them not merely as consumers of the animal 
 and vegetable substances which they devoured, but as disse- 
 minators of plants, and of the inferior classes of the animal king- 
 dom. I do not mean to insinuate that the very same changes 
 which man brings about, would have taken place by means of 
 the agency of other species, but merely that he supersedes a 
 certain number of agents ; and so far as he disperses plants 
 
 * Principles of Botany, p. 389. 
 
400 GEOGRAPHICAL DISTRIBUTION AND [Cn. XL. 
 
 unintentionally, or against his will, his intervention is strictly 
 analogous to that of the species so extirpated. 
 
 I may observe, moreover, that if, at former periods, the 
 animals inhabiting any given district have been partially 
 altered by the extinction of some species, and the introduction 
 of others, whether by new creations or by immigration, a 
 change must have taken place in regard to the particular 
 plants conveyed about with them to foreign countries. As, 
 for example, when one set of migratory birds is substituted 
 for another, the countries from and to which seeds are trans- 
 ported are immediately changed. Vicissitudes, therefore, 
 analogous to those which man has occasioned, may have 
 previously attended the springing up of new relations between 
 species in the vegetable and animal worlds. 
 
 It may also be remarked, that if man is the most active 
 agent in enlarging, so also is he in circumscribing, the geo- 
 graphical boundaries of particular plants. He promotes the 
 migration of some, he retards that of other species ; so that, 
 while in many respects he appears to be exerting his power 
 to blend and confound the various provinces of indigenous 
 species, he is, in other ways, instrumental in obstructing the 
 fusion into one group of the inhabitants of contiguous 
 provinces. 
 
 Botanists are well aware that garden plants naturalise 
 and diffuse themselves with great facility in comparatively 
 unreclaimed countries, but spread themselves slowly and with 
 difficulty in districts highly cultivated. There are many 
 obvious causes for this difference : by drainage and culture the 
 natural variety of stations is diminished, and those stray 
 individuals by which the passage of a species from one fit 
 station to another is effected, are no sooner detected by the 
 agriculturist than they are uprooted as weeds. The large 
 shrubs and trees, in particular, can scarcely ever escape obser- 
 vation, when they have attained a certain size, and will rarely 
 fail to be cut down if unprofitable. 
 
 The same observations are applicable to the interchange 
 of the insects, birds, and quadrupeds of two regions situated 
 like those above alluded to. No beasts of prey are permitted 
 to make their way across the intervening arable tracts. Many 
 
CH. XL.] MIGRATION OF SPECIES. 401 
 
 birds, and hundreds of insects, which would have found some 
 palatable food amongst the various herbs and trees of the 
 primeval wilderness, are unable to subsist on the olive, the 
 vine, the wheat, and a few trees and grasses favoured by 
 man. In addition, therefore, to his direct intervention, man, 
 in this case, operates indirectly to impede the dissemination 
 of plants, by intercepting the migration of animals, many of 
 which would otherwise have been active in transporting seeds 
 from one province to another. 
 
 We shall see in the sequel that species belonging to genera, 
 previously foreign to the province into which they are intro- 
 duced, often make their way more readily than plants of those 
 genera and species which are indigenous, a fact which has a 
 very important bearing on the theory of the origin of species. 
 It is unfavourable to the doctrine that new species have been 
 specially created in each station as best fitted of all possible 
 organisms to nourish there, while it agrees perfectly with the 
 view that new lands or stations are first .colonised by such 
 plants and animals as can gain access to them without 
 violating the fixed and immutable laws which govern the 
 diffusion of species. Once introduced, they may become 
 adapted by variation and selection to all the peculiar condi- 
 tions of the new region ; but they may still be less fitted for 
 it than some other organisms which may coexist on the globe, 
 and which may be prevented by impassable barriers from 
 reaching the same country so as to assert their superiority 
 in the battle of life. 
 
 VOL. II. D D 
 
402 
 
 CHAPTER XLI. 
 
 INSULAR FLORAS AND FAUNAS CONSIDERED WITH REFERENCE 
 TO THE ORIGIN OF SPECIES. 
 
 VOLCANIC ORIGIN AND MIOCENE AGE OF THE ATLANTIC ISLANDS ISLANDS 
 
 ONCE FORMED HAVE NOT BEEN SINCE SUBMERGED, NOR UNITED WITH OTHER 
 
 ISLANDS ARGUMENTS AGAINST CONTINENTAL EXTENSION MAP SHOWING 
 
 THE GREAT DEPTH OF THE OCEAN BETWEEN THE VOLCANIC ARCHIPELAGOS 
 OF THE WESTERN ATLANTIC AND THE MAINLAND SUBMARINE VOLCANIC 
 ERUPTIONS OF THE PRESENT CENTURY GENERAL INFERENCES TO BE DE- 
 DUCED FROM THE ENDEMIC AND OTHER SPECIES OF ANIMALS AND PLANTS 
 IN THE ATLANTIC ISLANDS FROM MAMMALIA FROM BIRDS FROM INSECTS 
 FROM PLANTS FROM LANDSHELLS SMALL NUMBER OF SPECIES OF 
 
 LAND SHELLS COMMON .TO MADEIRA AND PORTO SANTO PROPORTION OF 
 
 SPECIES COMMON TO MADEIRA AND THE DEZERTAS CONTRAST OF THE TESTA- 
 CEOUS FAUNA OF THE BRITISH ISLES AND THAT OF THE ATLANTIC ISLANDS 
 
 MODE IN WHICH AN OCEANIC ISLAND MIGHT BECOME PEOPLED WITH 
 
 LANDSHELLS VARIABILITY OF SPECIES NOT GREATER IN ISLANDS THAN ON 
 
 CONTINENTS. 
 
 IN the present chapter I shall consider the characteristic 
 features of the fauna and flora of islands remote from con- 
 tinents. It has been truly said, that the distribution of 
 species in such peculiar situations affords perhaps the severest 
 test by which the theory of Variation and Natural Selection 
 can be tried. 
 
 I have already stated that as a general rule, when islands 
 are near a continent, especially if they are only divided from 
 it by a shallow sea, less, for example, than 100 fathoms in 
 depth, their flora and fauna are identical with that of the 
 mainland. But when an island, like Madagascar, is of large 
 size, and is divided from the mainland by a deep channel of 
 the sea several hundred miles wide, the species of quadrupeds 
 differ from those on the continent, although nearly all the 
 genera are the same, while of the other members of the animal 
 and vegetable kingdom there is a greater or less identity 
 according to the class to which they belong. 
 
 If we then go a step farther, and contemplate small islands 
 
CH. XLL] INSULAR FLORAS AND FAUNAS CONSIDERED. 403 
 
 far from land and surrounded by a deep ocean, we find that 
 they are remarkable for the number of peculiar species of 
 animals and plants which they contain, even a single island of 
 the same group being sometimes inhabited by many species 
 exclusively belonging to it. Yet even in such localities an 
 affinity can be traced between the insular forms considered 
 as a whole, and those of the nearest continent a relationship 
 exceeding that which connects them with the fauna and flora 
 of more distant parts of the globe. 
 
 Volcanic origin and Miocene age of the Atlantic islands. I 
 shall refer chiefly to the Madeiras and Canaries as types of 
 oceanic archipelagos, as I have myself visited them and 
 studied their geological structure, without a knowledge of 
 which the speculations and theories of a zoologist or botanist 
 as to the mode in which they may have been peopled with living 
 beings must necessarily be most imperfect. For in the first 
 place we require information as to the period of the past to 
 which the origin of the islands can be traced back, and then we 
 have still to enquire whether they are fragments of a pre- 
 existing continent, or were formed in mid-ocean by volcanic 
 eruptions. 
 
 If we find evidence that in the case of the Atlantic 
 islands the latter conclusion is true, we have still to learn 
 whether each of them has continued above water during 
 the whole course of its growth by successive eruptions, or 
 whether it may have undergone oscillations of level, by alter- 
 nate upheaval and subsidence. To most of these questions 
 we are fortunately able to give a satisfactory answer. It 
 may be affirmed that the earliest eruptions took place in that 
 part of the Middle Tertiary period which I have called Upper 
 Miocene. As soon as the first solid lavas raised their heads 
 above water, they were exposed to the action of the waves, 
 and fragments of volcanic rocks were detached and rounded 
 on the shore, and some of them swept into the adjoining 
 deeper parts of the sea, so as to form pebble beds, or con- 
 glomerates, or sands and sandstones, in which corals and 
 shells of Miocene species were imbedded. By far the larger 
 number of these species are now extinct. Their fossil re- 
 mains have been rendered visible to us by their having been 
 
 DD 2 
 
404. INSULAR FLORAS AND FAUNAS WITH [Cn. XLI. 
 
 uplifted in various islands to great heights, especially in the 
 Grand Canary, Madeira, and Porto Santo, where they some- 
 times reach elevations of from 1,500 to 2,000 feet above the 
 level of the sea. The movement of elevation was, I believe, 
 very gradual, and went on during the whole period which 
 witnessed the piling up on these islands of several thousand 
 feet of basaltic and trachytic lavas, just as I have described 
 the gradual rise of the Marine Pliocene strata, which con- 
 stituted the foundations of Mount Etna during the accumu- 
 lation of the subaerial superstructure of the great cone.* 
 
 Nowhere could I detect, in any of the Atlantic islands 
 which I visited, any signs of subsidence, or even of the tem- 
 porary submergence of old terrestrial surfaces. In Madeira 
 there are hundreds of thin horizontal layers of a red- brick 
 colour, dividing those sheets of ancient lava which are seen 
 in the sea-cliffs or in precipices in the interior. They exactly 
 resemble a layer of burnt vegetable mould near Catania, already 
 described (p. 13), as having been overflowed in the year 1669 
 by a great lava-current, and all of them seem to be ancient 
 soils formed by the decomposition of lava and volcanic sand. 
 They bear testimony to the reiterated obliteration and renewal 
 of old habitable surfaces, unaccompanied by any signs of sub- 
 mergence or the intervention of the sea. The movements of 
 upheaval, on the other hand, seem to have been always partial 
 and confined within the limits of the separate islands in 
 which we find the marine strata uplifted. The 100 fathom 
 line is always near to the shore, f and outside of this line the 
 depth of water increases very rapidly, so that it is highly 
 improbable that any of the principal islands were united 
 and afterwards disjoined. Madeira would, indeed, be con- 
 nected with the Dezertas,J if the sea was to sink 100 fathoms ; 
 but there is no geological reason for presuming that the 
 intervening ridge, over which there is, in one part, more 
 than 400 feet of water, ever formed an unbroken isthmus 
 joining Chao to the south-eastern extremity of Madeira. 
 
 The great antiquity of the Canaries and Madeiras is at- 
 tested by the twofold evidence of the height and magnitude 
 of the islands themselves, and the age of the fossil organic 
 
 * Vol. ii. p. 5. t See Map, p. 405. J See Map. 
 
CH. XLL] REFERENCE TO THE ORIGIN OF SPECIES. 405 
 
 remains (of Miocene date) already alluded to as having been 
 imbedded in the products of early eruptions. 
 
 In Madeira the volcanic accumulations rise to the height 
 of 5,000 feet, and in the Grand Canary to 6,000 feet. The 
 highest crater in Teneriffe rises to an elevation of more than 
 12,000 feet above the sea-level. We know that violent erup- 
 tions are usually separated by long intervals of time ; and 
 from the history of the Canaries and volcanic archipelagos in 
 
 Fig. 137. 
 
 POR: 
 
 of the Madeiran Archipelago. 
 
 o. The Styx reef, 72 feet under water. 
 b. The Falcon reef, 26 feet under water. 
 
 general, we may infer that when one island is in a state of 
 unusual volcanic activity, the other adjoining islands enjoy 
 comparative repose. Moreover, in one and the same island, 
 different sets of vents have been in eruption in succession ; as, 
 for example, in Madeira, where the series of cones which now 
 constitute the highest and central ridge, is not the most 
 
406 INSULAR FLORAS AND FAUNAS WITH [Cn. XLI. 
 
 ancient, for lavas proceeding from those vents, and flowing 
 southwards, have overwhelmed the products of an older series 
 of eruptions.* 
 
 Scarcely any progress has been made as yet in tracing in 
 any of the archipelagos the passage from a Miocene to a 
 recent fauna and flora by aid of fossil remains preserved in 
 volcanic tuff; but Mr. Hartung and I were fortunate enough 
 to discover in 1854 at San Jorge in Madeira, in a deep ravine 
 at the height of 1,000 ft. above the sea, a layer of lignite con- 
 taining impressions of the leaves of forest trees and some 
 ferns. They appear to belong to some part of the Pliocene 
 period, and are certainly of great antiquity, for the nume- 
 rous beds of lava and layers of volcanic ash piled over them 
 are about 1,100 feet thick. Sir C. F. Bunbury, and after 
 him Professor Heer, have shown that these fossil leaves prove 
 Madeira to have been clothed, at the period when they were 
 imbedded (possibly in the mud at the bottom of an old crater) 
 with evergreens and other laurel-like trees, such as Laurus 
 and Oreodaphne mixed with species of European genera, 
 together with ferns, such as Woodwardia in fact, with just 
 such forests and such an undergrowth as we now find charac- 
 teristic of the native vegetation of the island. Some of the 
 species, however, according to Heer, differ from any now living 
 in Madeira, f 
 
 It is a favourite opinion of some naturalists, and one advo- 
 cated by the late Edward Forbes, that the Azores, Madeiras, 
 and Canaries are the last remaining fragments of a contin- 
 uous area of land, which once connected them with the West 
 of Europe and North Africa. In order to explain my reasons 
 for dissenting from this hypothesis, I may refer the reader to 
 the adjoining map, partly based on a chart in Maury's Physi- 
 cal Geography of the Sea, and partly on Admiralty charts, for 
 an analysis of which I am indebted to Mr. T. Saunders. A 
 glance at this map will satisfy the reader that the theory of 
 continental extension involves an amount of change of level 
 so vast, that to assume its occurrence since the close of the 
 Miocene epoch, is quite inconsistent with what we know of the 
 
 * See 'Lyell's Elements,' p. 639. 1854, vol. x. p. 326, and 'Lyell's Ele- 
 
 f See Bunbury, G-eol. Quart. Journ. ments,' 6th edit. p. 642. 
 
CH. XLL] KEFERENCE TO THE ORIGIN OF SPECIES. 
 
 407 
 
 constancy of the position of continents and oceanic basins 
 throughout long geological periods. The Azores, in which 
 the oldest fossiliferous rocks, like those of the Madeiras and 
 Canaries, are of Upper Miocene date, are everywhere sur- 
 rounded * by a zone of ocean more than 10,000 feet deep. 
 There is, indeed, one line of soundings having a depth of more 
 than 15,000 feet between the Azores and Portugal, showing- 
 Fig. 138. 
 
 Map, showing the depth of the ocean between the eastern volcanic archipelag( 
 of the North Atlantic and the Mainland. 
 
 The ocean is tinted according to its depth, thus : 
 
 From the coastline to a depth of 1,000 feet lightly 
 
 From 1,000 feet to 10,000 feet . . darker 
 
 Below 10,000 feet . . . very darkly 
 
 The line of 1,000 feet is lettered A. B., and the line of 10,000 feet C. D. 
 
 that a land communication would imply, first, the sinking of 
 a great continental area down to the sea-level, and then a 
 further depression of the same from the sea-level to a depth 
 
 * See Map. 
 
408 INSULAR FLORAS AND FAUNAS WITH [Cn. XLI. 
 
 of from 10,000 to 15,000 feet and upwards, all since the close 
 of the Miocene period. The Madeiran archipelago, it will be 
 seen, is near the line C D, which expresses a depth of 10,000 
 feet, and the same may be said of the eastern portion of the 
 Canarian archipelago. On the western side of this last, the 
 ocean has a depth of several thousand feet, dividing Fuerta- 
 ventura and Lanzerote from the mainland. The general 
 abruptness of the cliffs of all the Atlantic islands, coupled 
 with the rapid deepening of the sea outside the 100 fathom 
 line, are characters which favour the opinion that each island 
 was formed separately by igneous eruptions in a sea of great 
 depth. No geologist can doubt that the beds of lava and 
 volcanic ash originally sloped down gradually towards the 
 shore, and that the abrupt precipices now so general and often 
 from 1,000 to 2,000 feet in perpendicular height facing the 
 Atlantic, have been caused by the undermining action of the 
 waves. 
 
 Submarine volcanic eruptions of the present century. From 
 what we know of the modern history of volcanic action in the 
 basin of the Atlantic, we can be at no loss to conceive the 
 manner in which such groups as the Azores or Canaries 
 originated. I have already mentioned that the foundations 
 of a future archipelago seem now in the act of being laid 
 midway between St. Helena and Ascension, which are about 
 600 miles distant from each other.* Here in mid-ocean 110 
 less than 1,200 miles from the nearest part of Africa, un- 
 equivocal signs of submarine eruptions are occasionally wit- 
 nessed. On this spot, so far out of sight of land, we may 
 expect on some future day that a cone and crater will be 
 built up as was Sabrina in 1811, in the sea off St. Michael's, 
 one of the Azores, or as was Graham's Island, which in 1831f 
 rose up in a deep part of the Mediterranean, thirty miles 
 from the nearest land, the south coast of Sicily. Although 
 both these islands were gradually swept away by the waves, 
 they have left reefs of solid rock in that part of the sea from 
 which, on some future occasion, a new volcanic cone may 
 arise. 
 
 * See above, p. 64. f See above, p. 60. 
 
CH. XLL] REFERENCE TO THE ORIGIN OF SPECIES. 409 
 
 Even in the present year (November 1867) a submarine 
 volcano lias burst out in the South Pacific at a point 1,200 
 geographical miles from New Zealand and 1,800 from Aus- 
 tralia, between two of the most easterly islands of the Samoa 
 or Navigator's Group, an archipelago where there had been 
 no tradition of an eruption within the memory of man. This 
 outburst was preceded by numerous shocks of earthquakes. 
 Jets of mud and dense columns of volcanic sand and stones, 
 rising 2,000 feet, and the fearful crash of masses of rock 
 hurled upwards and coming in collision with others which 
 were falling, attested the great volume of ejected matter, 
 which accumulated in the bed of the ocean, although there 
 was no permanent protrusion of a new volcano above its level. 
 
 General inferences to be deduced from the endemic and other 
 species of animals and plants in the Atlantic Islands. Whether 
 therefore we consider the composition of the rocks and struc- 
 ture of the Atlantic islands, or their comparatively modern 
 origin, or the vast depth and extent of the sea which separates 
 them from the nearest continent, all these characters conspire 
 to lead to the belief that they have been formed in mid-ocean 
 by volcanic agency; and we shall find, if I mistake not, that the 
 geographical distribution of the species, both of animals and 
 plants, contained in them is far more in accordance with such 
 an hypothesis than with that of continental extension. If, 
 when the first islands were formed, the earliest colonists con- 
 sisted of plants and animals which arrived as waifs and strays 
 from the nearest land, they must have consisted of species 
 which inhabited Europe and the North of Africa in Upper 
 Miocene times. Fortunately we have made considerable pro- 
 gress in ascertaining what was the character of the fauna and 
 flora of that epoch, differing widely as it did from that now 
 existing in the same regions. We know, for example, that the 
 Miocene flora of Europe had a strong generic affinity to the 
 vegetation now characterising North America, much greater 
 than to that of any other part of the globe in our own period; 
 so that, if we find American forms in these Atlantic islands, 
 it does not violate the general law that the animate creation 
 in oceanic archipelagos bears always most resemblance to that 
 of the nearest adjoining mainland, for these American forms 
 
410 INSULAR FLOE AS AND FAUNAS WITH [Cn. XLI. 
 
 are doubtless the remnants of a flora derived from an ancient 
 and adjoining Miocene continent. But we must also re- 
 member that the Miocene fauna and flora of Europe gradu- 
 ally gave place to another of Pliocene date, and all these 
 fluctuations in the animate world must have made themselves 
 felt in the oceanic islands in which the successive destruction 
 and renovation of the terrestrial surfaces would facilitate the 
 settling in them of new species brought to them by the 
 winds, marine currents, and various agents of transport, or- 
 ganic and inorganic. New sheets of lava would in particular 
 weaken the barrier which preoccupancy opposes to new colo- 
 nists ; for the melted matter first annihilates every living 
 thing over the strip of land, more or less broad, which extends 
 from the volcanic orifice to the sea-coast, and then, after many 
 years, when the lava has decomposed, it affords a fresh and 
 virgin soil on which new immigrants may settle. Volcanic 
 ejections and movements of upheaval, by causing perpetual 
 variations in the surface-level of each island above the sea, 
 would also promote fluctuations in the fauna and flora. That 
 low portion of Africa which is marked in our map (fig. 138, 
 p. 407), as the Sahara, was probably under water during the 
 Miocene period. It is also possible that some volcanic islands 
 may, during or since the Miocene era, have been formed and 
 again destroyed within the area embraced in this map. They 
 may have played an important part in promoting the inter- 
 change of species between different archipelagos, or between 
 them and the continent. 
 
 It will be seen that at present, about half way between 
 Madeira and the Canaries, there are some isolated rocks 
 called the Salvages, which attain a height of 100 feet above 
 the sea. The largest of them which, like the rest, is unin- 
 habited, is about a mile long. They rise from a deep ocean, 
 and their steep cliffs show that they have been much reduced 
 in size by the waves. The plants, insects, and landshells 
 found upon them belong in part to those peculiar types called 
 f Atlantic,' probably the relics of a Miocene fauna and flora. 
 
 The foregoing remarks on the geography and geology of 
 the Atlantic islands are indispensable to a reader who would 
 follow us in our speculations on the manner in which they 
 
CH. XLI.J EEFERENCE TO THE OEIGIN OF SPECIES. 411 
 
 may have become peopled with the animals and plants now 
 inhabiting them. The absence or abundance of each class, 
 the number of species common to the nearest continent, the 
 range, whether limited or extensive, of each species through 
 different islands or through different archipelagos, may throw 
 light on the question whether species have been independently 
 created, or whether they are modifications of pre-existing 
 forms, the products of Variation and Natural Selection. 
 
 Mammalia. The first great fact for which we have to 
 account, is the entire absence of all indigenous Mammalia 
 except bats. Palma, one of the Canaries, is inhabited by an 
 indigenous bat, the progenitors of which may have migrated 
 to that island in Miocene or Pliocene times. 
 
 When we have travelled over large and fertile islands, 
 thirty miles or more in diameter, such as the Grand Canary 
 and Teneriffe, and have seen how many domestic animals, 
 such as camels, horses, asses, dogs, sheep and pigs, they now 
 support, we cannot but feel amazed that not even the smaller 
 wild animals, such as squirrels, field-mice, and weasels, should 
 be met with in a wild state. The reader may ask how such 
 quadrupeds could have reached an island like Madeira, more 
 than 360 miles from the nearest mainland ; but such a ques- 
 tion at once implies the admission, that an arbitrary exer- 
 tion of creative power does not give origin to Mammalia in 
 every region where conditions favourable to their support 
 may happen to exist. 
 
 It was long ago remarked by Dr. Prichard,* that among 
 the various groups of fertile islands in the Pacific, no quadru- 
 peds, with the exception of a few bats, have been met with, 
 which might not be supposed, like the dog, the hog, and the 
 rat, to have been conveyed thither from New Guinea by the 
 natives in canoes. What is more extraordinary, even the 
 large island of New Zealand, when first explored by Euro- 
 peans, was found to be destitute of indigenous Mammalia, 
 except one species of rat and two bats, said to be different 
 from any found elsewhere. Bats have been seen wandering 
 by day far over the Atlantic ocean, and two North American 
 
 * Prichard, Phys. Hist, of Mankind, vol. i. p. 75. 
 
412 INSULAR FLORAS AND FAUNAS WITH [Cn. XLI. 
 
 species visit the Bermudas at the distance of 600 miles from 
 the mainland.* Mr. Darwin has therefore emphatically 
 dwelt on the absence of Mammalia in islands far from con- 
 tinents, as strongly confirmatory of his theory of the origin 
 of all species by descent from pre-existing closely allied 
 species. The absence of Mammalia also supplies us with an 
 argument against the doctrine of continental extension. 
 Had a large tract of land stretching from Europe to the 
 Atlantic islands been gradually submerged, so that at last 
 no vestige of it remained above water, except the tops of 
 certain volcanic mountains, the Mammalia would have re- 
 treated into such spots, for the smaller species at least might 
 have found subsistence there. It has been suggested by the 
 advocates of continental extension, that if Java should sink 
 down several thousand feet, no land would be left except the 
 summits of a series of lofty volcanic cones, round which 
 there would be everywhere a deep ocean. But these same 
 cones, as we have seen (p. 356), would each of them be in- 
 habited by its peculiar Mydaus, and no doubt other species of 
 Mammalia would take refuge there. Had any quadrupeds 
 been able to swim to the Azores, Madeiras, or Canaries in the 
 Miocene epoch, there is no ground for supposing that their 
 descendants would not still survive; for, as before stated, each 
 island seems during its whole growth to have afforded a 
 habitable surface to terrestrial beings. 
 
 The rapid multiplication of goats when allowed to run 
 wild in St. Helena, and of both goats and dogs in Juan Fer- 
 nandez when introduced by the Spaniards, and of rabbits in 
 Porto Santo, from a single brood imported there in 1418, 
 prove the fitness of small islands to maintain wild quadrupeds, 
 if they can once make their way into them. 
 
 The total dearth of Batrachians (frogs, toads, and newts), 
 has also been pointed out by Darwin, as a characteristic of 
 oceanic islands ; yet he remarks that frogs, when taken to 
 Madeira, the Azores, and Mauritius, have thriven to such a 
 degree as to become a nuisance. If their spawn were 
 carried down by a river to the sea, it would at once be de- 
 
 * Origin of Species, p. 469. 
 
CH. XLL] REFERENCE TO THE ORIGIN OF SPECIES. 413 
 
 strojed by the saltwater, as lias been ascertained by experi- 
 ment, and it is not of a nature to adhere to the feet of birds, 
 as Mr. Darwin has found by observation. 
 
 A strong current which flows from the north, and passes 
 between the Atlantic archipelagos and the mainland, may 
 perhaps have prevented Mammalia and reptiles from reach- 
 ing even the Canaries, one of which, Fuertaventura, is now 
 only fifty miles from Africa, though possibly it was more 
 distant when the Sahara was still under water. The same 
 current may have prevented canoes from being drifted to 
 Madeira, which is so isolated in mid-ocean, and on the shores 
 of which no human being is believed to have ever landed 
 until the year 1419. Madeira now supports a population 
 of about 80,000 souls, and when we consider the great beauty 
 and fertility of the island, and that it has existed ever since 
 the Miocene epoch, we are not merely called upon to explain 
 the absence of inferior animals, but why, if we adopt the 
 theory of special creation, no race of mankind was formed 
 expressly to inhabit such a paradise. 
 
 Birds. For the same reason that bats, being provided with 
 wings, form an exception to the general rule of the absence 
 of Mammalia in oceanic islands, so we might expect that 
 the feathered race would, of all classes of Yertebrata, be 
 most fully represented. Accordingly we not only find this to 
 be the case, but what is still more significant, as bearing 
 on the theory of transmutation, almost all the birds in the 
 Atlantic islands are absolutely identical in species with 
 those of the nearest mainland. Thus in the Canaries and 
 Madeiras, all the species except three or four are European. 
 Of the 99 Madeiran species, there is only one peculiar to that 
 island, and it is closely related to a European form ; the 
 other two non-European species are common to the Canaries. 
 In the Azores, there are only two peculiar species, out of 
 51, and these two, a chafnnch and a bullfinch, are closely 
 allied to European and North African birds.* 
 
 We learn from Mr. Du Cane Godman, as before cited (p. 365), 
 that every winter some birds are driven by violent gales over 
 1,000 miles of ocean from England to the Azores. The same 
 
 * Ibis, vol. ii. 1866, new series. 
 
41 4 INSULAR FLORAS AND FAUNAS WITH [Cn. XLI. 
 
 observer informs us that the species are most numerous in the 
 easternmost islands, and that the number diminishes rapidly 
 as we examine those lying farther west, showing that the 
 wearied and hungry voyagers drop down on the first land 
 they discern. It is only by this frequent arrival of new- 
 comers that we can explain the specific identity of the insular 
 and continental fauna, the tendency to variation and in- 
 definite divergence being checked in the manner explained 
 at p. 321, by the absorption of the insular into the conti- 
 nental types, with which they are continually crossed. There 
 are no American birds in the Azores, which cannot be entirely 
 explained by the greater distance of that continent, because 
 no less than sixty species are known to have crossed the 
 Atlantic as stragglers, and to have reached the British Islands. 
 The fact simply proves that strong winds blowing continu- 
 ously in the right direction, are indispensable to enable birds 
 to colonise remote islands. 
 
 The Bermudas, which are 700 miles from the coasts of 
 America, are stocked with species all belonging to that conti- 
 nent. Of three European stragglers mentioned by Baird, two 
 are common to Greenland, and may have come from the 
 north, Newfoundland having served as an intermediate 
 halting-place ; and the third, our common sky-lark, a rare and 
 occasional visitor, is so often carried in ships to America, that 
 it may perhaps sometimes escape from a cage, and alight on 
 the first land which presents itself. 
 
 The number of days for which land-birds can fast would 
 more than suffice for their flight from Europe or even from 
 America to the Azores. Mr. Bartlett informs me that a par- 
 tridge sent from the London Zoological Gardens to the 
 country remained accidentally in the box in which it was 
 enclosed for five days without food or water ; when discovered, 
 it was alive, and being fed was soon restored to its usual 
 vigour. 
 
 The avifauna of the volcanic archipelago of the Galapagos 
 presents in some respects a contrast to that of the Atlantic 
 islands ; for although the distance from the nearest mainland 
 is scarcely more than half that which separates the Azores 
 from Europe, four-fifths of the land-birds are of species found 
 
CH. XLL] REFERENCE TO THE ORIGIN OF SPECIES. 415 
 
 nowhere else in tlie world. Out of twenty-six species all but 
 three or four are peculiar to these islands, at the same time 
 that the whole of them are of South American types. What 
 is still more worthy of note, several of these land-birds are 
 peculiar to a single island of the group.* To explain this 
 we may suppose that continuous gales have rarely blown 
 from South America to the Galapagos since these islands 
 first lifted their heads above the waves, and for this reason 
 stragglers have only arrived after long intervals, some on 
 one island, and some on another. Once established, they 
 have remained isolated, without communication with birds 
 of the parent stock on the South American mainland, or with 
 settlers of the same stock on other parts of the archipelago. 
 On this -subject Mr. Godman remarks, that while in the 
 Azores, winds are constantly blowing from all points of 
 the compass so that land-birds are carried during storms 
 from one island to another, in the Galapagos there are no 
 such violent gales, but usually uninterrupted calms. He 
 also adds, that while the marine currents in the Azores flow 
 in varying directions, those of the Galapagos are strong, 
 and always in the same direction. As to the web-footed 
 birds or waders of the Galapagos, Mr. Darwin found that 
 out of 11 species all except two consist of species common 
 to the nearest continent. f This fact agrees well with the 
 very wide range of this order of birds in all parts of the 
 world, and is in accordance with their migratory habits. 
 The relationship of the birds of the Atlantic islands to 
 those of Europe and North Africa is nearly the same as that 
 usually observed in a continuous continent. A few excep- 
 tional and peculiar types may in some cases have arisen 
 from Variation and Natural Selection, since they first arrived, 
 and some of them may perhaps be the descendants of Miocene 
 species or genera which have died out in the mother con- 
 tinent. 
 
 Insects. The insects of Madeira, the Salvages, and the 
 Canaries, unlike the birds, exhibit a large proportion of 
 indigenous species, and a great many genera peculiar to the 
 
 * Darwin, Origin of Species, p. 465. f Ibid. 
 
416 INSULAR FLORAS AND FAUNAS WITH [On. XLI. 
 
 Atlantic islands, represented in each separate archipelago bj 
 distinct species. Mr. T. V. Wollaston, in his ' Coleoptera 
 Atlantidum,' has described no less than 1,449 species of beetles 
 belonging to the three groups of islands above mentioned. 
 Nearly all of these have been collected by himself, and of the 
 whole number more than 1,000 are of species hitherto unknown 
 as inhabiting any other region, although there is no doubt that 
 a great many of them will hereafter be discovered in lands 
 bordering the Mediterranean. The distinctness of the fauna 
 of different archipelagos is shown by the fact that out of 
 1,007 species obtained from the Canaries, and 661 from the 
 Madeiras, only 238 are common to the two groups. Even 
 of these it is suspected that the larger number have been 
 introduced by man, and it is quite certain that 38 species 
 have been so imported in very modern times. 
 
 Nearly every detached island adds some distinct species or 
 marked variety to the general list, and one half of the 24 
 species found on the rocks called the Salvages, before men- 
 tioned, are peculiar, some of them belonging to those forms 
 which have been called Atlantic types. c If,' says Wollaston, 
 ' we exclude those beetles which have probably been natura- 
 lised by human agency, there are marvellously few species, 
 which permeate the whole of the archipelagos, yet with few 
 exceptions the genera are common to the whole.' Among the 
 dominant forms the weevils, or Curculionidce, preponderate 
 greatly, and certain families of them are of essentially 
 Atlantic types. No less than 50 species and varieties feed 
 exclusively on the Euphorbias which are so abundant and 
 diversified in form in the Canaries. Some fossil plants of 
 the genus Euphorbia occur in the Miocene strata of (Eninghen 
 in Europe, and the parent stock both of these plants and of 
 the Atlantic Curculionidce may perhaps have been derived from 
 the old Miocene continent. It has been already proved, by the 
 researches of Heer and others, that the Miocene Coleopterous 
 Eauna of Central Europe was actually richer than that now 
 living in the same latitudes ; * so that we may well imagine 
 that the various means of transport already alluded to (p. 379), 
 
 * See ' Lyell's Elements of Geology,' p. 254. 
 
CH.XLI.] REFERENCE TO THE ORIGIN OF SPECIES. 417 
 
 by which insects are often carried seaward, may have been 
 the means of introducing into the oceanic islands some of the 
 progenitors of the present insular fauna. 
 
 The inferior facilities enjoyed by insects as compared to 
 birds of crossing the sea, affords probably the true explana- 
 tion of the marked difference in the relationship of the two 
 faunas to that of the mother continent, and also the compara- 
 tively small number of insects common to different islands of 
 the same group. In proportion as the interchange of species 
 is an event of rare occurrence. Variation and Natural Selec- 
 tion will be efficacious in forming distinct races in separate 
 islands. 
 
 A recent examination of the beetles collected in the Azores 
 by Mr. Godman, and described by Mr. Crotch,* shows that 
 that archipelago presents the same phenomena as the Ca- 
 naries and Madeiras, although the proportion of Atlantic 
 types is smaller, and the living European forms more pre- 
 dominant. 
 
 Plants. Dr. Hooker, in his admirable essay on Insular 
 Floras,t remarks that in Madeira, besides the numerous culti- 
 vated plants which have been introduced by man, and the 
 poppies, fumitories, groundsels, and other weeds which he 
 has brought with him unintentionally, there are other native 
 varieties of European species, and sometimes representative 
 genera, which indicate a relationship to the nearest continent. 
 He also observes that whereas we find on ascending moun- 
 tains in Great Britain or on the continent of Europe, from 
 the height of 2,000 feet and upwards, species proper to more 
 northern latitudes, and differing from those flourishing at 
 lower levels, we do not meet with any such boreal forms in 
 Madeira even at the height of 4,000 feet, and from that to 
 6,000. The species become fewer as we ascend, but they con- 
 tinue to be the same as those which flourish at inferior eleva- 
 tions. Had the theory of continental extension been true, 
 we might have expected the Atlantic islands to have bor- 
 rowed their upland flora from higher latitudes during the 
 Glacial period. 
 
 * Azorean Coleoptera, Zool. Proc. f Lecture to Brit. Assoc. Notting- 
 
 1867 ; pt. ii. p. 359. ham, 1866 ; Gardener's Chronicle, 1867. 
 
 VOL. II. E E 
 
418 INSULAR FLORAS AND FAUNAS WITH [Cn. XLI. 
 
 A botanist, wholly ignorant of the plants which lived 011 
 the continent of Europe in Miocene times when the first 
 volcanos were beginning their eruptions in the Canaries, 
 Madeiras, and Azores, would be in no small degree perplexed 
 at the presence in these archipelagos of such Atlantic types 
 as Clethra and Persea, of which living representatives exist 
 in no part of the world nearer than the continent of North 
 America. It would seem to be a violation of the general 
 law according to which the organic productions of islands 
 bear most resemblance to those of the nearest continent. 
 But fortunately the labours of Unger, Heer, and Goppert 
 on the fossil botany of the tertiary strata have shown us 
 that Europe, when the Atlantic volcanos first reared their 
 crests above the waves, was covered with an exceedingly rich 
 vegetation. 
 
 No less than 900 species of these fossil plants have been 
 detected in the strata of a single locality at (Eninghen in 
 Switzerland.* The most conspicuous feature, says Heer, in 
 this ancient flora, is the large number of genera of plants 
 now peculiar to America ; whereas those having European 
 affinities only hold the second rank, those of Asia the third, 
 of Africa the fourth, and those of Australia the fifth. Among 
 the prevailing American forms are Clethra and Persea, above 
 alluded to, genera common to Madeira, the Canaries, and 
 Azores. Regarded as relics of a Miocene flora, they are just 
 such forms as we should naturally expect to have come from 
 the adjoining Miocene continent. Another plant of a sin- 
 gularly aberrant form, and which we may well imagine to be 
 the last survivor of a Miocene type, is the Monizia edulis, 
 belonging to a genus which has now no representative else- 
 where in the world. This conspicuous shrub is an umbellife- 
 rous plant with a stem like an inverted elephant's trunk, 
 crowned with a huge tuft of parsley-like foliage. A fine 
 specimen of it may now (1867) be seen growing in the green- 
 house of the Botanical Garden at Kew. It is peculiar to one 
 of the rocky islands of the Dezertas,f where it probably owes 
 its preservation to the exceptional conditions which it has there 
 
 * For a brief sketch of the Miocene 6th ed. chap. xv. 
 flora and fauna, see 'Lyell's Elements,' f See Map, fig. 137, p. 405. 
 
CH.XLL] KEFEREXCE TO THE ORIGIN OF SPECIES. 4iy 
 
 enjoyed cut off from all communication with other islands, into 
 which new colonists, both of the animal and vegetable worlds, 
 have been able more freely to penetrate. 
 
 Dr. Hooker reminds us that the extinction of so many 
 species and of some genera which nourished in the Miocene 
 period in Europe, is fully accounted for by the great change 
 of climate which the temperate latitudes of the northern 
 hemisphere experienced in Pliocene and Glacial times. The 
 old subtropical species, which had long nourished in Central 
 Europe and in the regions bordering the Mediterranean, 
 gave way before a more southern flora, but many plants and 
 not a few of the insects, which were extirpated on the con- 
 tinent, may well have survived in oceanic islands which 
 enjoyed a milder and more equable temperature. To this 
 source we may probably refer those peculiar e Atlantic types ' 
 above alluded to, which pervade all the archipelagos. We 
 are informed by Dr. Hooker that the seeds of the West 
 Indian bean-like climber Entada were floated to the Azores 
 3,000 miles by the Gulf-stream. These seeds, after such 
 long immersion in salt water, although they could not stand 
 the climate of the Azores, germinated in the Garden at Kew ; 
 from which fact we learn how easily seeds of the Miocene 
 period may have been carried uninjured by currents from the 
 Mediterranean region to any one of the Atlantic islands, 
 as none of them are so far from Europe as are the Azores 
 from the West Indies. But it is probably to birds more 
 than to marine currents that new islands owe the plants 
 which clothe them. We have already seen (p. 394) how 
 many seeds which have been swallowed by birds and ejected 
 in their dung, germinate freely, and these, if carried by a 
 land-bird driven to a new volcanic island, would soon cover 
 the unoccupied ground, until other species brought by a 
 similar mode of transport came to dispute their monopoly. 
 
 It is not easy to conjecture how many different modes of 
 transport nature may have employed in peopling some At- 
 lantic islands. Even icebergs may have played their part in 
 carrying plants to the Azores in the Glacial period, for they 
 are now sometimes floated to latitudes farther south than 
 that archipelago, as we have already stated (Yol. I. p. 246) . 
 
 E E 2 
 
420 INSULAR FLORAS AND FAUNAS WITH [On. XLI. 
 
 Mr. Harking found fragments of rock in the Azores which, he 
 regarded as erratics or of iceborne origin. When, indeed, 
 we consider all the changes in climate, and in the direction 
 of winds and currents, and in the species of birds which have 
 occurred in the lapse of millions of years since the Miocene 
 epoch, to say nothing of the incessant transformations under- 
 gone by the volcanic islands themselves, we must feel that 
 the colonisation of the several archipelagos has been the 
 result of such a complexity of causes and conditions, that 
 the distribution of species is not more anomalous or ca- 
 pricious in its character than we might reasonably have 
 anticipated. If we find a plant or animal peculiar to a 
 single island, we may suppose it to have been first brought 
 there as a straggler from the adjoining continent, and it may 
 never have been able to spread to any other island ; or it 
 may have had a wider range until dispossessed of most of its 
 former stations by new intruders, or by volcanic eruptions ; 
 or lastly, the parent stock may still flourish in some one of 
 the islands or archipelagos, but the descendants may have 
 gone on diverging from the original type, until, in the lapse 
 of millions of generations, the amount of difference may be 
 of specific value. When it is said that the Atlantic types, 
 whether of plants or insects, are common to the Azores, 
 Madeiras, and Canaries, it is only the genera which are 
 spoken of, for the species are almost always distinct in each 
 archipelago. 
 
 Mr. Darwin had said in his ' Origin of Species,'* that we 
 probably still remain ignorant of many means of transoceanic 
 migration which will one day be discovered. These antici- 
 pations have been singularly verified even since the appear- 
 ance of the last edition of his celebrated work. Hearing that 
 many new plants had been observed to spring up in Southern 
 Africa in districts which had been invaded by locusts, he 
 procured from a correspondent, Mr. Weale, residing in Natal, 
 a small packet of dry locust dung, weighing less than half 
 an ounce. Seeds were extracted from the middle of several 
 pellets, and their true nature ascertained by dissection, and 
 
 * Chap. xi. 4th ed. p. 433. 1866. 
 
CH. XLI.] REFERENCE TO THE ORIGIN OF SPECIES. 421 
 
 others were sown, and when they had germinated, no less 
 than seven individuals belonging to at least two kinds of 
 grasses were obtained. A locust of the migratory species 
 blown from the coast of Africa was taken on one occasion by 
 Mr. Darwin himself when at sea, at a distance of 370 miles 
 from the nearest land, or somewhat farther than is Madeira 
 from Africa. The same naturalist observed in 1867 some 
 mud adhering firmly to the foot of a woodcock, which 
 weighed when dry nine grains. He extracted from it the 
 seed of the Juncus Euphonious, which germinated. This fact 
 throws much light on the colonisation of new islands by 
 plants, for of all orders even of wading birds the woodcocks 
 are perhaps the most migratory, and there is scarcely a remote 
 island which they do not sometimes reach. 
 
 When we compare the flora of any one of the Atlantic archi- 
 pelagos that of the Madeiras for example with that of the 
 British Islands, the diiference in the number of indigenous 
 species and in the proportion of plants common to the 
 nearest continent is truly marvellous. In the British area 
 there is only a single peculiar plant of the phsenogamous 
 class, one of the orchids, Spiranthes gemmipora, out of 1,500 
 species. In the Madeiras there are hundreds of indigenous 
 species, although the entire flora is not half so numerous as the 
 British. On the other hand, all the British plants are species 
 common to the continent of Europe, except two, the Spiranthes 
 above mentioned, and a North American water-plant, Erio- 
 caulon septangulare. 
 
 Landshells. I have reserved to the last my comments 
 on the landshells, as their geographical distribution in 
 the Atlantic islands is more singular and instructive than 
 that of any other class of living beings. In the Ma- 
 deiran archipelago especially, as was long ago pointed out 
 by the Eev. R. T. Lowe, every island has its distinct species, 
 and the whole fauna differs almost entirely from that of 
 every other archipelago as well as from that of Europe and 
 Africa. Moreover, it is when we contemplate these air- 
 breathing mollusks that we find the contrast between the 
 Atlantic and British islands to have reached its climax; 
 for in Great Britain no one of the different islands is charac- 
 
422 INSULAR FLOKAS AND FAUNAS WITH [Cn. XLI. 
 
 terised by peculiar species, and the insular and adjoining con- 
 tinental faunas are the same. 
 
 Mr. Lowe, in the year 1884, described 71 species of land- 
 shells of the genera Helix, Bulimus, Achatina, &c., from the 
 Madeiran archipelago, 44 of which were new. He then 
 stated that but few of these were common to the Canaries, 
 and, what was still more astonishing, only two were common 
 to the islands of Madeira and Porto Santo, divided by a 
 sea only 30 miles wide. Since his memoir was published 
 his own further investigations, and those of Mr. Wollaston. 
 and others, have augmented the list of species, and taught 
 us that some few of those before known had a wider range 
 than was at first supposed ; but notwithstanding these 
 additions to our knowledge, the general conclusions an- 
 nounced in 1834 hold good, or are even rendered more 
 striking. The instruction derived from this fauna is greatly 
 enhanced by the occurrence, both in Madeira and in Porto 
 Santo, of large assemblages of fossil shells which reveal to 
 us the state of this part of the animal creation in the Newer 
 Pliocene period. Some few of the fossil species are extinct, 
 but most of them are the same as those now inhabiting 
 Madeira and Porto Santo respectively ; consequently the two 
 ancient groups of shells are as dissimilar as are the two 
 recent ones. From this we learn that in the Newer Pliocene 
 period the two islands must have been disjoined, as they are 
 now. It is also clear that at .that period neither island was 
 united with the continent of 'Europe ; for scarcely any of the 
 fossil species are European, and the absence of these confirms 
 the general opinion of naturalists that almost all the species 
 now living in this archipelago and common to the continent 
 have been introduced by man since the beginning of the 
 fifteenth century. During my short stay in Madeira there 
 was found in the earth of a single flower-pot in which a 
 garden plant had been sent from Lisbon no less than three 
 species of Portuguese Helices, showing us how unconsciously 
 the horticulturist is busied in alloying the purity of the 
 native fauna. Most of the European shells have been found 
 in the gardens of Funchal, from which principal town as 
 from a centre they radiate for greater or less distances. 
 
CH. XLL] REFERENCE TO THE ORIGIN OF SPECIES. 423 
 
 At the time of my visit in 1854 the known living species 
 of Madeira proper, excluding the modern intruders above 
 alluded to, amounted to 56, and those of Porto Santo to 42 ; 
 only 12 of the whole being common to both islands; and, 
 what is of no small significance, even some of these 12 
 being represented in the two islands by distinct varieties. 
 In truth, the discordance is more like that of two of the 
 six great zoological provinces of the globe before described, 
 than of two islands of the same province in sight of each other. 
 If we then refer to the fossil groups, we find 36 species in 
 Madeira and 35 in Porto Santo, only 8 being common to 
 the two islands, and 5 of these 8 being represented by 
 distinct varieties in each island respectively. It was to be 
 expected that as Porto Santo is much less cultivated than 
 Madeira, and has only a small human population, the fossil and 
 living species should agree much more with each other than 
 do those of Madeira ; and the fact that they do so encourages 
 us to reject as spurious or as modern interlopers those 
 landshells now living in Madeira which are missing in the 
 fossil group of that island. These fossils occur at Cani9al 
 near the eastern extremity of Madeira,* in prodigious 
 numbers, imbedded in a superficial deposit of calcareous 
 sand and mud. Among the most common is a conspic- 
 uous species of an unusual form named Helix delphinula 
 (from its resemblance to the marine genus Delphinula}, 
 which has entirely disappeared from the Atlantic islands. 
 Another smaller but very characteristic shell, Helix tia- 
 rella, must have swarmed in the Newer Pliocene period, 
 but it has now became so extremely rare that for a long 
 time it was supposed to be extinct, until a few surviv- 
 ing individuals were detected by Mr. Wollaston, in 1855, 
 at a great height on some precipitous and nearly inac- 
 cessible rocks in the interior of Madeira. Two species of 
 Achatina and two of Pupa, also fossil at Cani9al, are supposed 
 to have disappeared from the living creation, but as they are 
 of small dimensions they may possibly have been overlooked, 
 although, if extant, they must have become very scarce. 
 
 * See Map, fig. 137, p. 405. 
 
424 INSULAR FLORAS AND FAUNAS WITH [Cir. XLI. 
 
 In the shelly sand of Porto Santo a conspicuous shell, 
 Helix Lowei, is very abundant. It is of so large a size that 
 it could hardly have escaped detection if it still existed on 
 either of the principal islands, but lately a few individuals 
 of this species have been detected on the rock called Ilheo 
 di Cima off Porto Santo.* By some conchologists Helix 
 Lowei is regarded as a gigantic variety of the living H. 
 Porto sanctana, which also occurs fossil in the same sands. 
 If this opinion be correct, it offers by no means the only 
 example in the fauna of this archipelago of the same distinct 
 races being found both fossil and recent, and in both cases 
 without any intermediate varieties. One of the two forms 
 may possibly represent the parent stock, and the other the 
 extreme of divergence. There must once have existed, 
 according to the theory of Natural Selection, all the transi- 
 tional forms between the two extremes. But these forms 
 may have died out for want of favourable conditions, or may 
 have been absorbed into one or other of the extremes, which 
 last may be able to maintain their ground on the principle 
 before alluded to (p. 323), according to which more plants or 
 animals find support in a limited area if they are of many 
 different genera then if they all belong to one genus. There 
 are however in the Madeiran archipelago some polymorphous 
 species, such as Helix polymorpha, in which the transitional 
 links between the extremes are not missing, and they remind 
 us of the varieties of the English brambles and roses ; but 
 such cases are the exception to the rule, for reasons to be 
 explained in the next chapter. 
 
 I have alluded to Helix tiarella in Madeira ; an allied re- 
 presentative of the same peculiar form, H. coronata, abounds 
 in a fossil state in Porto Santo, and is also still living in 
 that island, though it is rare. Another, or third closely allied 
 species, H. coronula, was first found fossil in Bugio, one of 
 the Dezertas, and it probably still exists on some part of those 
 inaccessible rocks, for a few living individuals have lately been 
 found on the nearest adjoining coast of Madeira. They 
 may supply an example of the smaller island having yielded 
 one of its indigenous species to Madeira ; for the absence 
 
 * See Map, fig. 137, p. 405. 
 
CH. XLL] REFERENCE TO THE ORIGIN OF SPECIES. 425 
 
 of this shell among the fossils of Carnal seems to imply 
 that it has only recently gained access to Madeira proper. 
 These three distinct though kindred forms of a peculiar 
 division of the Helicidse belonging to Madeira, Porto Santo, 
 and the Dezertas remind us of the representative species 
 of some genera found in Asia, Europe, and America. 
 
 Having alluded to the Dezertas, I may add that 19 species 
 of landshells have been found on them, 12 of which, or about 
 two-thirds of the whole, are common to Madeira, and only 
 5 to Porto Santo. The nearer affinity of the fauna to 
 Madeira was to be expected, not only because of its greater 
 proximity, but because, as will be seen by our map, Madeira 
 and the Dezertas stand within the same 100 fathom line, 
 and the channel between them may once have been narrower, 
 although there is no reason for believing that the land was 
 ever continuous, or even that Chao, Dezerta Grande, and 
 Bugio were ever united 5 for each of these rocks has some 
 species of shells as well as some varieties peculiar to itself. 
 It is worth remarking, as showing the limited range of 
 species when the whole archipelago is considered, that there 
 are only two species of landshells common to all the three 
 faunas of Madeira, the Dezertas, and Porto Santo. 
 
 The antiquity of the fossils of Madeira and Porto Santo 
 is unmistakable, although they are more modern than the 
 newest lava streams ; for to say nothing of the time required 
 to annihilate several species and greatly to alter the relative 
 numbers of others, there are proofs of local geographical 
 changes of subsequent date. Since the accumulation of 
 the volcanic sand and mud, in which the landshells are 
 enveloped, there has been much undermining of the sea-cliffs, 
 both in the narrow promontory in which Cam^al is situated 
 and on the northern coast of Porto Santo. Some of the 
 shelly formation of the last-mentioned island consists of 
 sand-dunes which have been cut off abruptly in the vertical 
 cliffs, and must once have extended farther in a seaward 
 direction. The whole island, indeed, of Porto Santo has 
 suffered great denudation, and some rocks indicated by the 
 letters a b in our map (fig. 137), one of them called the Falcon, 
 now covered by only 26 feet of water, and the other the 
 
426 INSULAR FLORAS AND FAUNAS WITH [Cn. XLI. 
 
 Styx by 72 feet, may perhaps mark the site of isolated 
 volcanic cones which once rose above the sea-level. But that 
 the whole space within the 100 fathom line* was ever con- 
 tinuous land, I can by no means conceive. Such an ex- 
 tension would give to Porto Santo five times its present 
 dimensions. The proportion of extinct species as compared 
 to the living ones in Madeira and Porto Santo is about 8 
 per cent., which may perhaps be slightly diminished by the 
 future discovery of some of the smaller species ; but the real 
 discordance between the ancient and modern fauna will never 
 disappear, for it is even greater than is expressed by the 
 numerical statements above given, some species formerly 
 most dominant being now very feebly represented, and some 
 fossil races as well as species having become extinct. 
 
 The landshells of the Canaries, when we exclude those 
 which have probably been introduced by man, are very 
 distinct from those of Madeira. The different islands in the 
 Canaries have more species in common than the Madeiras, 
 but this fusion may be partly owing to the remote and un- 
 known period at which the aboriginal inhabitants, the 
 Guanchos, settled there. 
 
 Contrast of the testaceous fauna of the British isles and that 
 of the Atlantic islands. I shall now revert to the extraordinary 
 contrast between the distribution of landshells in the At- 
 lantic and British islands. If a curved line be drawn from 
 the Azores through Madeira to the Canaries, its length would 
 be about 750 miles, or about equal to a line drawn from the 
 Shetland islands through Scotland and England to the Scilly 
 islands. The British archipelago contains more than 200 
 islands, when we include the Shetlands, Orkneys, Hebrides, and 
 others. In all of these the landshells are the same, whereas 
 in the Atlantic archipelagos it is not only the principal or 
 habitable islands, but almost every uninhabited rock off the 
 coast, which supplies the conchologist with peculiar species 
 or varieties. In the British area, it would seem at first sight, 
 as if the land-snails had never had any difficulty in crossing 
 the sea, whereas in the Atlantic archipelagos the narrowest 
 
 * See Map, fig. 137, p. 405. 
 
CH. XLL] REFERENCE TO THE ORIGIN OF SPECIES. 427 
 
 marine channels have formed in most cases impassable barriers. 
 The Scilly islands are as far from Cornwall as is Madeira 
 from Porto Santo, yet in them the conchologist obtains no 
 distinct species, nor even any marked races, whereas, on 
 crossing from Madeira to Porto Santo, he finds four-fifths 
 of the species different, besides some peculiar races, even of 
 those shells which are common to the two sides of the 
 channel. It may, no doubt, be said that the southern parts of 
 England display a richer fauna, and contain certain species 
 (about eight), which do not range farther northwards than 
 Yorkshire. These are; Helix pomatia, H. cartusiana, H. 
 revelata, H. Pisana, H. obvoluta, Bulimus montanus, Clausilia 
 Rodolphi, and C. biplicata. It is more difficult to name 
 species which are peculiar to the north, Vertigo alpestris 
 affording perhaps a solitary example.* 
 
 In what manner, then, can we explain or refer to one and 
 the same law of distribution the apparently incongruous 
 phenomena exhibited in the two regions above compared ? 
 Some zoologists who have been struck with the unusual 
 
 O 
 
 number of endemic species and marked varieties observed 
 in oceanic islands, have suggested that the terrestrial mol- 
 lusca must be more variable than other classes of the 
 animal kingdom. But this idea is wholly inadmissible, for 
 we need go no farther than the fossil faunas of Madeira and 
 Porto Santo, above alluded to, to prove the remarkable con- 
 stancy and persistency of form of the genera Helix, Pupa,Acha- 
 tina, and Clausilia, from the Newer Pliocene era to our own 
 times. To solve the enigma we must appeal to the immense 
 difference in the lapse of time, during which the islands of 
 the British and those of the Atlantic archipelagos have 
 remained separate from each other and from the nearest con- 
 tinents. In the one case we have to deal with thousands, in 
 the other with millions, of years. f In the one case there 
 has been everywhere a land communication between every 
 part of the archipelago since the commencement of the 
 Glacial period, when the species of marine and terrestrial 
 testacea were everywhere the same as they are now ; in the 
 
 * See Mr. .T. Gwyn Jeffreys, British f See above, Vol. I. p. 300. 
 
 Conchology, 1866-67. 
 
428 INSULAR FLORAS AND FAUNAS WITH [Cn. XLI. 
 
 other there has been no land communication since the 
 Miocene epoch, when the whole fauna and flora of the globe 
 bore but a distant resemblance to that now established. Our 
 map (p. 407) will satisfy the reader, that if the bed of the 
 Atlantic were everywhere uplifted 100 fathoms, all the 
 principal archipelagos and islands would remain as dis- 
 connected as they are now, whereas we know that a similar 
 upward movement would unite every one of the 200 British 
 islands with each other and with the continent. Indeed, 
 nearly all of them would be joined to the mainland and to 
 each other with a change of level of less than 400 feet.* That 
 there have been great movements of oscillation in the British 
 area since the Glacial period is proved by independent geo- 
 logical evidence, whereas there are no signs, as before stated, 
 of any general movements of like magnitude in the Atlantic 
 area, but only here and there some evidence of partial 
 upheaval. 
 
 I have already remarked that had Porto Santo been united 
 with Madeira proper in the Newer Pliocene period, the two 
 fossil faunas would have been fused together, instead of 
 being as different as are the living native shells of the two 
 islands. In Great Britain, also, we have a fossil fauna of 
 terrestrial shells associated with the bones of the Mammoth 
 and other extinct mammalia in ancient drift ; and this enables 
 us to carry back the comparison of the Atlantic and British 
 archipelagos one step farther. We recognise in the British 
 fossils the same uniformity, or wide range of species, as 
 in the actual or recent fauna. No less than 48 species 
 of fossil landshells were collected by the late Mr. John 
 Brown from the Post-Pliocene drift of Copford in Essex, and 
 with the exception of two Helices, (which still survive on the 
 continent,) all are of living British species. But if England 
 had been submerged a few hundred feet, and divided into 
 islands, even since the Pliocene period, we might have ex- 
 pected the shells associated with extinct quadrupeds in 
 different counties to display some marked want of agreement 
 in species and varieties. There is however no such contrast. 
 
 * See Map, fig. 41, ' Antiquity of Man,' by the author, p. 279. 
 
CH. XLL] REFERENCE TO THE ORIGIN OF SPECIES. 429 
 
 If, for example, we compare the landshells of the Wilt- 
 shire drift, near Salisbury, of the age of the Mammoth, with 
 those of Essex before mentioned, places twice as far apart 
 as are Madeira and Porto Santo, they exhibit no difference 
 whatever in the species of fossil landshells. From this fact 
 we may infer that although the British area has been partially 
 submerged since the commencement of the Glacial period, 
 yet its normal state has been a continental one. 
 
 Mode in which an oceanic island might become peopled with 
 landshells. The reader may well ask, if Madeira and Porto 
 Santo have made so little progress in interchanging their 
 respective species of landshells in the course of that vast 
 lapse of ages which has occurred since the Newer Pliocene 
 period, how could any of the Atlantic archipelagos ever have 
 become peopled by migration from Europe or Africa ? The 
 enigma is certainly perplexing, and we must assume that the 
 arrival of landshells, as waifs and strays from a continent, is 
 an exceedingly rare event. It has been suggested that birds 
 may transport across the sea the eggs of these mollusks in 
 mud attached to their feet. But if so, why have the birds 
 which fly freely across the channel, only 30 miles wide, be- 
 tween Madeira and Porto Santo, allowed the fauna of these 
 two islands to remain so distinct ? or why have those birds 
 which arrive every year from the continent in the Atlantic 
 islands introduced so few landshells ? Hitherto the naturalist 
 has not witnessed the arrival of a new continental Helix on 
 any remote oceanic island, except by the aid of man ; and to 
 those who are unwilling to abandon in despair all hope of 
 solving the problem, it is satisfactory that such should be 
 the case. How inexplicable would be the dearth of land 
 quadrupeds in the Atlantic islands if some members of 
 this class were seen occasionally to swim across the ocean 
 from Europe to the Azores ! 
 
 If hereafter we should discover the mode in which air- 
 breathing mollusks can sometimes traverse a wide expanse 
 of ocean, we may be sure that the occasions of transport will 
 be few and far between, so that a continental species when 
 it colonises a new island has time to vary and to give rise 
 to one or two new races, before other representatives of the 
 
430 INSULAR FLORAS AND FAUNAS WITH [Cn. XLI. 
 
 original continental type follow in the same direction, so as 
 to cross with the first settlers and check divergence. 
 
 If floating timber, or land-birds, or insects, or any other 
 causes organic or inorganic, serve as the means of transport, 
 their agency must be so casual and irregular as to cause the 
 results to appear capricious in the extreme. 
 
 The first Miocene Helix which reached Madeira may have 
 been of a different species from the first which reached Porto 
 Santo. It has been imagined that Helix inflexa Martens, an 
 extinct Miocene* form of Europe, may have been the parent 
 stock of H. portosanctana, of which the gigantic H. Lowei 
 may be a variety, but the last-mentioned form seems never to 
 have reached Madeira. The extinct H. Raymondi, so common 
 in the French Faluns or Upper Miocene strata, is supposed 
 to have been the ancestral type of another common shell, 
 H. Bowditchiana Pfeiffer, found both fossil and recent in 
 Madeira and Porto Santo. 
 
 Let us assume that certain Miocene species, nearly all 
 of them long since extinct, were carried as waifs and strays 
 to separate islands by a concurrence of circumstances so 
 rare as to happen once only in several hundred thousand 
 years, other combinations of circumstances almost equally 
 rare might be required to convey a species from one island 
 to another. A volcanic eruption, for example, which might 
 only occur once in the whole course of the building up of 
 an archipelago, at exactly the same season of the year, or 
 at the same height above the sea, with equal violence and 
 when the wind or marine currents were in the same direction. 
 Such a convulsion might cause the dispersion of some 
 Helices from one part of an archipelago to another in a 
 manner altogether without parallel during the antecedent 
 or subsequent history of the same region. If the reader will 
 refer to our description of the birth of Monte Nuovo, Yol. I. 
 p. 608, near Naples, in 1538, he will see that while many 
 land-birds were killed, those which escaped and flew terrified 
 from the scene of the catastrophe, must, like the human 
 inhabitants, have been covered with mud which was showered 
 down so as to envelope all things. In the beginning of such 
 an eruption trees, shrubs, and vegetable soil, in which the 
 
CH. XLL] REFERENCE TO THE ORIGIN OF SPECIES. 431 
 
 eggs of landshells must sometimes be included, were hurled 
 up into the air by the aqueous vapour. The eggs of a pupa 
 are sometimes so minute and their terminal velocity in air so 
 slight that they might be carried many miles by the wind 
 before alighting on the ground as far perhaps as from Ma- 
 deira to the Dezertas. There is no reason for supposing 
 that the tendency of species to form new varieties is greater 
 in an oceanic island than on a continent. But if islands be 
 separated from each other throughout so long a period as 
 would be sufficient on the continent to change most of the 
 species, then it is evident that there will be a greater manu- 
 facture of new species in the islands. Let us suppose a band 
 of emigrants to have gone from some European country a 
 thousand years ago and to have formed colonies in the Azores, 
 Canaries, and Madeiras, and that all communication between 
 them and the mother country and between the different 
 archipelagos was cut off for a thousand years, there would then 
 be in all probability four languages spoken between the 
 mother country and her three colonies all different from the 
 original tongue of the ninth century. The population of 
 the three archipelagos, like the area of land formed by the 
 whole of them, might be very insignificant compared with 
 that of the country from which the first emigrants pro- 
 ceeded, yet the smaller number of islanders, in consequence of 
 their isolation, would have given rise to three new languages, 
 and the inhabitants of the continent to one only. Not that 
 the invention of new terms and idioms or the disuse of old 
 ones would have gone on at a greater rate in the islands, 
 but because each archipelago being separated from every other 
 one and from the rest of the world, had formed an independent 
 linguistic centre. In like manner the distinctness of the 
 landshells in the Canaries, Madeiras, and Azores, and in 
 many of the separate islands of each, are the results of the 
 prolonged isolation of small fragments of land in mid-ocean, 
 not of a greater tendency in the testacea inhabiting such 
 islands to vary. 
 
 In conclusion I may observe, that the extent to which the 
 species of mammalia, birds, insects, landshells, and plants, 
 (whether flowering or cryptogamous,) agree with continental 
 
432 INSULAK FLORAS AND FAUNAS CONSIDERED. [Cn. XLI. 
 
 species, or the degree in which, those of different archipe- 
 lagos or of different islands of the same group agree with 
 each other, has an unmistakable relation to the known faci- 
 lities enjoyed by each class of crossing the ocean. Such a 
 relationship accords well with the theory of Variation and 
 Natural Selection, but with no other hypothesis yet suggested 
 for explaining the origin of species. 
 
433 
 
 CHAPTEE XLII. 
 
 EXTINCTION OF SPECIES. 
 
 CONDITIONS 'WHICH ENABLE EACH SPECIES OF PLANT TO MAINTAIN ITS 
 GROUND AGAINST OTHERS EQUILIBRIUM: IN THE NUMBER OF SPECIES HOW 
 PRESERVED AGENCY OF INSECTS IN PRESERVING THIS EQUILIBRIUM DEVAS- 
 TATIONS CAUSED BY LOCUSTS EFFECT OF OMNIVOROUS ANIMALS IN PRESERV- 
 ING THE EQUILIBRIUM OF SPECIES RECIPROCAL INFLUENCE OF AQUATIC AND 
 TERRESTRIAL SPECIES HOW CHANGES IN PHYSICAL GEOGRAPHY AFFECT THE 
 DISTRIBUTION OF SPECIES EXTENSION OF THE RANGE OF ONE SPECIES 
 ALTERS THAT OF OTHERS SUPPOSED EFFECTS OF THE FIRST ENTRANCE OF 
 THE POLAR BEAR INTO ICELAND INCREASE OF REIN-DEE B IMPORTED INTO 
 ICELAND INFLUENCE OF MAN IN DERANGING THE NUMERICAL STRENGTH 
 OF SPECIES INDIGENOUS QUADRUPEDS AND BIRDS EXTIRPATED IN GREAT 
 BRITAIN EXTINCTION OF THE DODO RAPID PROPAGATION OF DOMESTIC 
 
 QUADRUPEDS OVER THE AMERICAN CONTINENT POWER OF EXTERMINATING 
 
 SPECIES NO PREROGATIVE OF MAN CONCLUDING REMARKS ON EXTINCTION. 
 
 CONDITIONS WHICH ENABLE EACH SPECIES OF PLANT TO 
 
 MAINTAIN ITS GROUND AGAINST OTHERS. I propose in this 
 
 chapter to treat of the various causes to which the continual 
 extinction of species, both in the animal and vegetable 
 creation, are due. 
 
 Every naturalist is familiar with the fact, that although in 
 a particular country, such as Great Britain, there may be 
 more than 3,000 species of plants, 12,000 insects, and a 
 great variety in each of the other classes ; yet there will 
 not be more than 100, perhaps not half that number, in- 
 habiting any given locality. There may be no want of 
 space in the supposed limited area : it may be a large 
 mountain, or an extensive moor, or a great river-plain, 
 containing room enough for individuals of every species in 
 our island ; yet the spot will be occupied by a few to the 
 exclusion of many, and these few are enabled, throughout 
 long periods, to maintain their ground successfully against 
 every intruder, notwithstanding the facilities which species 
 
 VOL. II. F F 
 
434 EXTINCTION OF SPECIES. [Cn. XLIL 
 
 enjoy, by virtue of those powers of diffusion already men- 
 tioned (Chapters XXXYIIL, XXXIX., XL.), of invading 
 adjacent territories. 
 
 The principal causes which enable a certain assemblage of 
 plants thus to maintain their ground against all others de- 
 pend, as is well known, on the relations between the physio- 
 logical nature of each species, and the climate, exposure, 
 soil, and other physical conditions of the locality, and the 
 power of each to compete with other organic beings in the 
 struggle for life. Some plants live only on rocks, others in 
 meadows, a third class in marshes. Of the latter, some 
 delight in a fresh-water morass, others in salt marshes, 
 where their roots may copiously absorb saline particles. 
 Some prefer an alpine region in a warm latitude, where, 
 during the heat of summer, they are constantly irrigated by 
 the cool waters of melting snows. To others loose sand, 
 so fatal to the generality of species, affords the most proper 
 station. The Carex arenaria and the Etymus arenarius 
 acquire their full vigour on a sandy dune, obtaining an ascen- 
 dancy over the very plants which in a stiff clay would imme- 
 diately stifle them. 
 
 Where the soil of a district is of so peculiar a nature that 
 it is extremely favourable to certain species, and agrees ill 
 with every other, the former get exclusive possession of the 
 ground, and as in the case of heaths, live in societies. In 
 like manner the bog moss (Sphagnum) is fully developed in 
 peaty swamps, and becomes, like the heath, in the language 
 of botanists, a social plant. Such monopolies, however, are 
 not common, for they are checked by various causes. Not 
 only are many species endowed with equal powers to obtain 
 and keep possession of similar stations, but each plant, for 
 reasons not fully explained by the physiologist, has the 
 property of rendering the soil where it has grown less fitted 
 for the support of other individuals of its own species, or 
 even other species of the same family. Yet the same spot, 
 so far from being impoverished, is improved, for plants of 
 another family. Oaks, for example, render the soil more fertile 
 for the fir tribe, and firs prepare the soil for oaks. Every 
 agriculturist feels the force of this law of the organic world, 
 and regulates accordingly the rotation of his crops. 
 
CH. XLIL] EQUILIBRIUM IN THE NUMBER OF SPECIES. 435 
 
 Equilibrium in the number of species, how preserved. ( All 
 the plants of a given country,' says De Candolle, in his 
 usual spirited style, ' are at war with one another. The first 
 which establish themselves by chance in a particular spot 
 tend, by the mere occupancy of space, to exclude other 
 species the greater choke the smaller ; the longest livers 
 replace those which last for a shorter period; the more 
 prolific gradually make themselves masters of the ground, 
 which species multiplying more slowly would otherwise fill.' 
 In this continual strife, he observes, it is not always the 
 resources of the plant itself which enable it to maintain or 
 extend its ground. Its success depends, in a great measure, 
 on the number of its foes or allies, among the animals and 
 plants inhabiting the same region. Thus, for example, a 
 herb which loves the shade may multiply, if some tree with 
 spreading boughs and dense foliage flourish in the neigh- 
 bourhood. Another, which, if unassisted, would be over- 
 owered by the rank growth of some hardy competitor, is 
 ecure because its leaves are unpalatable to cattle ; which, on 
 tie other hand, annually crop down its antagonist, and rarely 
 uffer it to ripen its seed. 
 
 Oftentimes we see some herb which has flowered in the 
 midst of a thorny shrub, when all the other individuals of the 
 ame species, in the open fields around, are eaten down, and 
 annot bring their seed to maturity. In this case, the shrub 
 las lent his armour of spines and prickles to protect the 
 lefenceless herb against the mouths of the cattle ; and thus 
 i, few individuals which occupied, perhaps, the most unfavour- 
 able station in regard to exposure, soil, and other circum- 
 tances, may, nevertheless, by the aid of an ally, become the 
 mncipal source whereby the winds are supplied with seeds 
 which perpetuate the species throughout the surrounding 
 ract.* Thus, in the New Forest in Hampshire, the young 
 >aks which are not consumed by the deer, or uprooted by 
 :he swine, are often indebted to the holly for their escape. 
 
 In the above examples we see one plant shielding another 
 rom the attacks of animals ; but instances are, perhaps, still 
 
 * Amoen. Acad. vol. vi. p. 17, 12. 
 F F 2 
 
436 EXTINCTION OF SPECIES. [Cn. XLII. 
 
 more numerous, where some animal defends a plant against 
 the enmity of some other subject of the vegetable kingdom. 
 Scarcely any beast, observes Linnaeus, will touch the nettle, 
 but fifty different kinds of insects are fed by it.* Some of 
 these seize upon the root, others upon the stem ; some eat 
 the leaves ; others devour the seeds and flowers : but for this 
 multitude of enemies, the nettle (Urtica dioica) would anni- 
 hilate a great number of plants. The same naturalist tells 
 us, in his ' Tour in Scania,' that goats were turned into an 
 island which abounded with the Agrostis arundinacea, where 
 they perished by famine; but horses which followed them 
 grew fat on the same plant. The goat, also, he says, thrives 
 on the meadow-sweet and water-hemlock, plants which are 
 injurious to cattle. f 
 
 Agency of insects. Every plant, observes Wilcke, has its 
 proper insect allotted to it to curb its luxuriancy, and to 
 prevent it from multiplying to the exclusion of others. 
 Thus grass in meadows sometimes flourishes so as to exclude 
 all other plants : here the Phalcena graminis (Bonibyx gram.), 
 with her numerous progeny, finds a well-spread table ; they 
 multiply in immense numbers, and the farmer, for some 
 years, laments the failure of his crop ; but, the grass being 
 consumed, the moths die with hunger, or remove to another 
 place. Now the quantity of grass being greatly diminished, 
 the other plants, which were before choked by it, spring up, 
 and the ground becomes variegated with a multitude of diffe- 
 rent species of flowers. Had not Nature given a commission 
 to this minister for that purpose the grass would destroy a 
 great number of species of vegetables, of which the equili- 
 brium is now kept up.'J 
 
 In the above passage allusion is made to the ravages com- 
 mitted in 1 740, and the two following years, in many provinces 
 of Sweden, by a most destructive insect. The same moth is 
 said never to touch the foxtail grass, so that it maybe classed 
 as a most active ally and benefactor of that species, and as 
 peculiarly instrumental in preserving it in its present abun- 
 dance^ A discovery of Eolander, cited in the treatise of 
 
 * Amcen. Acad., vi. p. 17, 12. j Ibid. vol. vi. p. 17, 11, 12. 
 
 t Ibid. rol. vii. p. 409. Kirby and Spence, vol. i. p. 178. 
 
CH. XLIL] AGENCY OF INSECTS. 437 
 
 Wilcke above mentioned, affords a good illustration of the 
 checks and counter-checks which Nature has appointed to 
 preserve the balance of power among species. ' The Phalcena 
 strobilella has the fir-cone assigned to it to deposit its eggs 
 upon ; the young caterpillars coming out of. the shell consume 
 the cone and superfluous seed ; but, lest \ the destruction 
 should be too general, the Ichneumon strobilellce lays its eggs in 
 the caterpillar, inserting its long tail in the openings of the 
 cone till it touches the included insect, for its body is too large 
 to enter. Thus it fixes its minute egg upon the caterpillar, 
 which being hatched, destroys it.' * 
 
 Entomologists enumerate many parallel cases where insects, 
 appropriated to certain plants, are kept down by other insects, 
 and these again by parasites expressly appointed to prey on 
 them.t Few, perhaps, are in the habit of duly appreciating 
 the extent to which insects are active in preserving the 
 balance of species among plants, and thus regulating in- 
 directly the relative numbers of many of the higher orders 
 of terrestrial animals. The peculiarity of their agency con- 
 sists in their power of suddenly multiplying their numbers to 
 a degree which could only be accomplished in a considerable 
 lapse of time in any of the larger animals, and then as 
 instantaneously relapsing, without the intervention of any 
 violent disturbing cause, into their former insignificance. 
 
 If, for the sake of employing, on different but rare occasions, 
 a power of many hundred horses, we were under the necessity 
 of feeding all these animals at great cost in the intervals 
 when their services were not required, we should greatly 
 admire the invention of a machine, such as the steam-engine, 
 which was capable at any moment of exerting the same 
 degree of strength without any consumption of food during 
 periods of inaction. The same kind of admiration is strongly 
 excited when we contemplate the powers of insect life, in the 
 creation of which the Author of Nature has been so prodigal. 
 A scanty number of minute individuals, to be detected only 
 by careful research, are ready in a few days, weeks, or 
 months, to give birth to myriads, which may repress any 
 
 * Amccn. Acad. vol. vi. p. 26, 14. f Kirby and Spence, vol. iv. p, 218. 
 
438 EXTINCTION OF SPECIES. [Cn. XLII. 
 
 degree of monopoly in another species, or remove nuisances, 
 such, as dead carcasses, which might taint the air. But no 
 sooner has the destroying commission been executed than 
 the gigantic power becomes dormant each of the mighty 
 host soon reaches the term of its transient existence, and 
 the season arrives when the whole species passes naturally 
 into the egg, and thence into the larva and pupa state. In 
 this defenceless condition it may be destroyed either by the 
 elements, or by the augmentation of some of its numerous 
 foes which may prey upon it in the early stages of its trans- 
 formation ; or it often happens that in the following year 
 the season proves unfavourable to the hatching of the eggs 
 or the development of the pupse. 
 
 Thus the swarming myriads depart which may have covered 
 the vegetation like the aphides, or darkened the air like 
 locusts. In almost every season there are some species which 
 in this manner put forth their strength, and then, like Mil- 
 ton's spirits, which thronged the spacious hall, ' reduce to 
 smallest forms their shapes immense '- 
 
 So thick the aery crowd 
 
 Swarm'd and were straiten' d ; till, the signal given, 
 Behold a wonder ! they but now who seemed 
 In bigness to surpass earth's giant sons, 
 Now less than smallest dwarfs. 
 
 A few examples will illustrate the mode in which this 
 force operates. It is well known that, among the countless 
 species of the insect creation, some feed on animal, others on 
 vegetable matter; and, upon considering a catalogue of 
 8,000 British Insects and Arachnidse, Mr. Kirby found 
 that these two divisions were nearly a counterpoise to each 
 other, the carnivorous being somewhat preponderant. There 
 are also distinct species, some appointed to consume living, 
 other dead or putrid animal and vegetable substances. One 
 female, of Musca camaria, will give birth to 20,000 young ; 
 and the larvse of many flesh-flies devour so much food 
 in twenty-four hours, and grow so quickly, as to increase their 
 weight two hundred-fold ! In five days after being hatched 
 they arrive at their full growth and size, so that there was 
 ground, says Kirby, for the assertion of Linnseus, that three 
 
Cn. XLII.] AGENCY OF INSECTS. 439 
 
 flies of M. vomitoria could devour a dead horse as quickly as 
 a lion;"* and another Swedish naturalist remarks, that so 
 great are the powers of propagation of a single species even 
 of the smallest insects, that each can commit, when required, 
 more ravages than the elephant.f 
 
 Next to locusts, the aphides, perhaps, exert the greatest 
 power over the vegetable world, and, like them, are sometimes 
 so numerous as to darken the air. The multiplication of these 
 little creatures is without parallel, and almost every plant has 
 its peculiar species. Reaumur has proved that in five gene- 
 rations one aphis may be the progenitor of 5,904,900,000 
 descendants ; and it is supposed that in one year there may 
 be twenty generations. J Mr. Curtis observes that, as among 
 caterpillars we find some that are constantly and unalterably 
 attached to one or more particular species of plants, and 
 others that feed indiscriminately on most sorts of herbage, so 
 it is precisely with the aphides : some are particular, others 
 more general feeders ; and as they resemble other insects in 
 this respect, so they do also in being more abundant in some 
 years than in others. In 1793 they were the chief, and in 
 1798 the sole, cause of the failure of the hops. In 1794, a 
 season almost unparalleled for drought, the hop was perfectly 
 free from them ; while peas and beans, especially the former, 
 suffered very much from their depredations. 
 
 The ravages of the caterpillars of some of our smaller moths 
 afford a good illustration of the temporary increase of a 
 species. The oak trees of a considerable wood have been 
 stripped of their leaves as bare as in winter, by the caterpillars 
 of a small green moth (Tortrix viridana), which has been ob- 
 served the year following not to abound. The silver Y moth 
 (Plusia gamma), although one of our common species, is not 
 dreaded by us for its devastations ; but legions of their cater- 
 pillars have at times created alarm in France, as in 1735. 
 Reaumur observes that the female moth lays about 400 eggs ; 
 so that if twenty caterpillars were distributed in a garden, and 
 all lived through the winter and became moths in the 
 succeeding May, the eggs laid by these, if half of them were 
 
 * Kirby and Spence, vol. i. p. 250. J Kirby and Spence, vol. i. p. 1 74. 
 
 f Wilcke, Amcen. Acad. c. ii. Trans. Linn. Soc. vol. vi. 
 
4*0 EXTINCTION OF SPECIES. [On. XLIL 
 
 female and all fertile, would in the next generation produce 
 800,000 caterpillars.* A modern writer, therefore, justly 
 observes that, did not Providence put causes in operation to 
 keep them in due bounds, the caterpillars of this moth alone, 
 leaving out of consideration the 2,000 other British species, 
 might soon destroy more than half of our vegetation. 
 
 In the latter part of the last century an ant most destruc- 
 tive to the sugar-cane (Formica saccharivora) , appeared in 
 such infinite hosts in the island of Granada, as to put a stop 
 to the cultivation of that vegetable. Their numbers were 
 incredible. The plantations and roads were filled with them ; 
 many domestic quadrupeds, together with rats, mice, and 
 reptiles, and even birds, perished in consequence of this plague. 
 It was not till 1780 that they were at length annihilated by 
 torrents of rain, which accompanied a dreadful hurricane. t 
 
 Devastations caused by locusts. We may conclude by 
 mentioning some instances of the devastations of locusts in 
 various countries. Among other parts of Africa, Cyrenaica 
 has been at different periods infested by myriads of these 
 creatures which have consumed nearly every green thing. 
 The effect of the havoc committed by them may be estimated 
 by the famine they occasioned. St. Augustine mentions a 
 plague of this kind in Africa which destroyed no less than 
 800,000 men in the kingdom of Massinissa alone, and many 
 more upon the territories bordering upon the sea. It is also 
 related, that in the year 591, an infinite army of locusts mi- 
 grated from Africa into Italy ; and, after grievously ravaging 
 the country, were cast into the sea, when there arose a pesti- 
 lence from their stench which carried off nearly a million of 
 men and beasts. 
 
 In the Venetian territory, also, in 1478, more than 30,000 
 persons are said to have perished in a famine occa- 
 sioned by this scourge ; and other instances are recorded of 
 their devastations in France, Spain, Italy, Germany, &c. In 
 different parts of Eussia also, Hungary, and Poland, in Arabia 
 and India, and other countries, their visitations have been 
 periodically experienced. Although they have a preference for 
 
 * Reaumur, vol. ii. p. 337. 
 
 t Kirby and Spence, vol. i. p. 183. Castle, Phil. Trans., sxx. 346. 
 
CH. XLIL] DEVASTATIONS CAUSED BY LOCUSTS. 441 
 
 certain plants, yet, when these are consumed, they will attack 
 almost all the remainder. In the accounts of the invasions 
 of locusts, the statements which appear most marvellous relate 
 to the prodigious mass of matter which incumbers the sea 
 wherever they are blown into it, and the pestilence arising 
 from its putrefaction. Their dead bodies are said to have 
 been, in some places, heaped one upon another, to the depth 
 of four feet, in Eussia, Poland, and Lithuania ; and when, in 
 Southern Africa, thoy were driven into the sea, by a north- 
 west wind, they formed, says Barrow, along the shore, for 
 fifty miles, a bank three or four feet high.* But when we 
 consider that forests are stripped of their foliage, and the 
 earth of its green garment, for thousands of square miles, it 
 may well be supposed that the volume of animal matter pro- 
 duced may equal that of great herds of quadrupeds and nights 
 of large birds suddenly precipitated into the sea. 
 
 The occurrence of such events at certain intervals, in hot 
 countries, like the severe winters and damp summers return- 
 ing after a series of years in the temperate zone, may affect 
 the proportional numbers of almost all classes of animals and 
 plants, and probably prove fatal to the existence of many 
 which would otherwise thrive there ; while, on the contrary, 
 the same occurrences can scarcely fail to be favourable to 
 certain species which, if deprived of such aid, might not main- 
 tain their ground. 
 
 Although it may usually be remarked that the extraordinary 
 increase of some one species is immediately followed and 
 checked by the multiplication of another, yet this does not 
 always happen ; partly because many species feed in common 
 on the same kinds of food, and partly because many kinds of 
 food are often consumed indifferently by one and the same 
 species. In the former case, where a variety of different 
 animals have precisely the same taste, as, for example, when 
 many insectivorous birds and reptiles devour alike some 
 particular fly or beetle, the unusual numbers of these insects 
 may cause only a slight and almost imperceptible augmen- 
 tation of each of these species of bird and reptile. In the 
 other instance, where one animal preys on others of almost 
 
 * Travels in Africa, p. 257. Kirby and Spence, vol. i. p. 215, 
 
442 EXTINCTION OF SPECIES. [Cn. XLII. 
 
 every class, as, for example, where some of our English hawks 
 or buzzards (Buteo) devour not only small quadrupeds, as rab- 
 bits and field-mice, but also birds, frogs, lizards, and insects, 
 the profusion of any one of these last may cause all such 
 general feeders to subsist more exclusively upon the species 
 thus in excess, by which means the balance may be restored. 
 
 Agency of omnivorous animals. The number of species 
 which are nearly omnivorous is considerable ; and although 
 every animal has, perhaps, a predilection for some one de- 
 scription of food rather than another, yet some are not even 
 confined to one of the great kingdoms of the organic world. 
 Thus, when the racoon of the West Indies can procure 
 neither fowls, fish, snails, nor insects, it will attack the sugar- 
 canes, and devour various kinds of grain. The civets, when 
 animal food is scarce, maintain themselves on fruits and roots. 
 Numerous birds, which feed indiscriminately on insects and 
 plants, are perhaps more instrumental than any other of the 
 terrestrial tribes in preserving a constant equilibrium between 
 the relative numbers of different classes of animals and vege- 
 tables. If the insects become very numerous and devour the 
 plants, these birds will immediately derive a larger portion of 
 their subsistence from insects, just as the Arabians, Syrians, 
 and Hottentots feed on locusts, vt hen the locusts devour their 
 crops. 
 
 Reciprocal influence of aquatic and terrestrial species. The 
 intimate relation of the inhabitants of the water to those of 
 the land, and the influence exerted by each on the relative 
 number of species, must not be overlooked amongst the com- 
 plicated causes which determine the existence of animals and 
 plants in certain regions. A large portion of the amphibious 
 quadrupeds and reptiles prey partly on aquatic plants and 
 animals, and in part on terrestrial ; and a deficiency of one kind 
 of prey causes them to have immediate recourse to the other. 
 The voracity of certain insects, as the dragon-fly, for example, 
 is confined to the water during one stage of their transfor- 
 mations, and in their perfect state to the air. Innumerable 
 water-birds, both of rivers and seas, derive in like manner 
 their food indifferently from either element ; so that the abun- 
 dance or scarcity of prey in one induces them either to forsake 
 
CH. XLIL] MEANS OF EXTINCTION VERY VARIOUS. 443 
 
 or more constantly to haunt the other. Thus an intimate 
 connection between the state of the animate creation in a lake 
 or river, and in the adjoining dry land, is maintained; or 
 between a continent, with its lakes and rivers, and the ocean. 
 It is well known that many birds migrate, during stormy 
 seasons, from the sea-shore into the interior, in search of food ; 
 while others, on the contrary, urged by like wants, forsake 
 their inland haunts, and live on substances rejected by the tide. 
 
 The migration of fish into rivers during the spawning sea- 
 son supplies another link of the same kind. Suppose the 
 salmon to be reduced in numbers by some marine foes, as by 
 seals and grampuses, the consequence must often be, that in 
 the course of a few years the otters at the distance of several 
 hundred miles inland, will be lessened in number from the 
 scarcity of fish. On the other hand, if there be a dearth of 
 food for the young fry of the salmon in rivers and estuaries, 
 so that few return to the sea, the sand-eels and other marine 
 species, which are usually kept down by the salmon, will 
 swarm in greater profusion. 
 
 It is unnecessary to accumulate more illustrations in order 
 to prove that the stations of different plants and animals 
 depend on a great complication of circumstances, on an 
 immense variety of relations in the state of the animate and 
 inanimate worlds. Every plant requires a certain climate, 
 soil, and other conditions, and often the aid of many animals, 
 in order to maintain its ground. Many animals feed on 
 certain plants, being often restricted to a small number, and 
 sometimes to one only ; other members of the animal kingdom 
 feed on plant-eating species, and thus become dependent on 
 the conditions of the stations not only of their prey, but of 
 the plants consumed by them. 
 
 How changes in physical geography affect the distribution of 
 species. Thus by means of numerous checks and counter- 
 checks the state of the animal and vegetable kingdoms con- 
 tinues from century to century, and even perhaps for tens of 
 thousands of years, the same, except where man interferes ; 
 but independently of human intervention, neither the zoolo- 
 gical nor botanical provinces can remain for indefinite periods 
 unaltered. 
 
444 EXTINCTION OF SPECIES. [On. XLII. 
 
 Nature is continually engaged in the task of sowing seeds 
 and colonising animals ; were this not the case the depopu- 
 lation of a certain portion of the habitable sea and land 
 would, even in a few years, be considerable, so great is the 
 instability of the earth's surface. Whenever a river trans- 
 ports sediment into a lake or sea, so as materially to diminish 
 its depth, the aquatic animals and plants which delight in 
 deep water are expelled : the tract, however, is not allowed 
 to remain useless; but is soon peopled by species which 
 require more light and heat, and thrive where the water is 
 shallow. Every addition made to the land by the encroach- 
 ment of the delta of a river banishes many aquatic species 
 from their native abodes ; but the new-formed plain is not 
 permitted to lie unoccupied, being instantly covered with 
 terrestrial vegetation. The ocean devours continuous lines 
 of sea-coasts, and precipitates forests or rich pasture land 
 into the waves ; but this space is not lost to the animate 
 creation ; for shells and sea-weeds soon adhere to the new- 
 made cliffs, and numerous fish people the channel which the 
 current has scooped out for itself. No sooner has a volcanic 
 island been thrown up than some lichens begin to grow upon 
 it, and it is sometimes clothed with verdure while smoke and 
 ashes are still occasionally thrown from the crater. The 
 cocoa, pandanus, and mangrove take root upon the coral reef 
 before it has fairly risen above the waves. The burning stream 
 of lava that descends from Etna rolls through the stately 
 forest, and converts to ashes every tree and herb which stands 
 in its way ; but the black strip of land thus desolated is covered 
 again, in the course of time, with oaks, pines, and chestnuts, 
 as luxuriant as those which the fiery torrent swept away. 
 
 Every flood and landslip, every wave which a hurricane or 
 earthquake throws upon the shore, every stream of lava or 
 shower of volcanic dust and ashes which buries a country far 
 and wide to the depth of many feet, every advance of the 
 sand-flood, every conversion of salt water into fresh, when 
 rivers alter their main channel of discharge, every permanent 
 variation in the rise or fall of tides in an estuary these and 
 countless other causes displace, in the course of a few 
 centuries, certain plants and animals from stations which 
 
CH. XLIL] VICISSITUDES IN THE EAETH'S SUKFACE. 445 
 
 they previously occupied. If, therefore, the Author of Nature 
 had not been prodigal of those numerous contrivances, before 
 alluded to, for spreading all classes of organic beings over 
 the earth if He had not ordained that the fluctuations of the 
 animate and inanimate creation should be in perfect harmony 
 with each other, it is evident that considerable spaces, now 
 the most habitable on the globe, would soon be as devoid 
 of life as are the Alpine snows, the dark abysses of the 
 ocean, or the moving sands and salt plains of the Sahara. 
 
 The powers, then, of migration and diffusion, conferred, as 
 already shown, on animals and plants, are indispensable to 
 enable them to maintain their ground, and would be necessary, 
 even though it were never intended that a species should 
 gradually extend its geographical range. But a facility of 
 shifting their quarters being once given, it cannot fail to 
 happen that the inhabitants of one province should occasion- 
 ally penetrate into some other ; since the strongest of those 
 barriers which I before described as separating distinct regions 
 are all liable to be thrown down, one after the other, during 
 the vicissitudes of the earth's surface. 
 
 We have seen in the Twelfth Chapter * how vast a suc- 
 cession of changes in the physical geography of the globe has 
 been revealed to us by geology. Although these changes are 
 incessant they proceed at so slow a rate that mankind at large 
 are wholly unconscious of their reality. It would not be easy 
 for the naturalist to take account of the advantage which one 
 species may gain over another in the course of a few centuries, 
 even at those points on the borders of two distinct provinces 
 where the struggle for existence is most keen. At such 
 points the rate of change must far outstrip the average 
 pace at which it proceeds in the organic world generally. 
 If the ocean should gradually wear its way through an 
 isthmus, like that of Suez, it would open a passage for the 
 intermixture of the aquatic tribes of two seas (the Mediter- 
 ranean and Bed Sea) previously disjoined, and would, at the 
 same time, close a free communication which the terrestrial 
 plants and animals of two continents had before enjoyed. 
 
 * Vol. I. p. 248. 
 
446 EXTINCTION OF SPECIES. [On. XLII. 
 
 These would be, perhaps, the most important consequences, in 
 regard to the distribution of species, which would result from 
 the breach made by the sea in such a spot ; but there would 
 be others of a distinct nature, such as the conversion of a 
 certain tract of land, which formed the isthmus, into the sea. 
 This space, previously occupied by terrestrial plants and 
 animals, would be immediately delivered over to the aquatic ; 
 a local revolution which might have happened in innumer- 
 able other parts of the globe, without being attended by any 
 alteration in the blending together the species of two distinct 
 provinces. 
 
 So if the narrow isthmus of Panama were to sink down 
 gradually, a communication would at length be established 
 between two seas which are now inhabited by fish, mollusks, 
 crustaceans, and other aquatic tribes nearly all of them speci- 
 fically distinct. A contest would take place between thousands 
 of allied species which in the course of time would give rise to 
 the predominance of some and the decline or total extinction 
 of others. If Spain were joined to Morocco, by the upheaval 
 and laying dry of the submarine ridge 1,000 feet deep, before 
 described,* the Mediterranean fauna would be separated 
 from that of the Atlantic, and there would be a fusion of the 
 terrestrial plants of Northern Africa with those of Southern 
 Europe. Or we may imagine a, land communication to be 
 caused by volcanic outbursts in the straits of Lonibok,f 
 uniting the islands of Bali and Lombok. This would bring 
 about a conflict between the land-birds, insects, and plants 
 of the Indian and Australian provinces, which could not 
 fail to add. to the numerical predominance of some species 
 at the expense of others, while some might be exterminated. 
 But even such fluctuations would to a human observer appear 
 slow in the extreme, because a communication formed by a 
 new volcanic island will not simply take thousands of years, but 
 perhaps thousands of centuries, for its accomplishment, and 
 few of the species capable of profiting by the removal of the old 
 barrier would wait till the two islands were completely joined. 
 Extension of the range of one species alters that of others. In 
 reference to the extinction of species it is important to bear 
 
 * See above, Vol. I. p. 562. f See Map, fig. 132, p. 347. 
 
CH. XLII.] INCREASE OF ONE SPECIES DIMINISHES OTHERS. 447 
 
 iii mind, that when any region is stocked with as great a 
 variety of animals and plants as its productive powers will 
 enable it to support, the addition of any new species to the 
 permanent numerical increase of one previously established, 
 must always be attended either by the local extermination or 
 the numerical decrease of some other species. 
 
 There may undoubtedly be considerable fluctations from 
 year to year, and the equilibrium may be again restored with- 
 out any permanent alteration ; for, in particular seasons, a 
 greater supply of heat, humidity, or other causes, may aug- 
 ment the total quantity of vegetable produce, in which case 
 all the animals subsisting on vegetable food, and others which 
 prey on them, may multiply without any one species giving 
 way : but whilst the aggregate quantity of vegetable produce 
 remains unaltered, the progressive increase of one animal or 
 plant implies the decline of another. 
 
 All agriculturists and gardeners are familiar with the fact 
 that when weeds intrude themselves into the space appro- 
 priated to cultivated species, the latter are starved in their 
 growth or stifled. If we abandon for a short time a field or 
 garden, a host of indigenous plants, 
 
 The darnel, hemlock, and rank fumitory, 
 
 pour in and obtain the mastery, extirpating the exotics, or 
 putting an end to the monopoly of some native plants. 
 
 If we enclose a park, and stock it with as many deer as the 
 herbage will support, we cannot add sheep without lessening 
 the number of the deer ; nor can other herbivorous species 
 be subsequently introduced, unless the individuals of each 
 species in the park become fewer in proportion. 
 
 So, if there be an island where leopards are the only beasts 
 of prey, and the lion, tiger, and hysena afterwards enter, the 
 leopards, if they stand their ground, will be reduced in num- 
 ber. If the locusts then arrive and swarm greatly, they may 
 deprive a large number of plant-eating animals of their food, 
 and thereby cause a famine, not only among them, but among 
 the beasts of prey : certain species, perhaps, which had the 
 weakest footing in the island may thus be annihilated. 
 Although our knowledge of the history of the animate creation 
 
448 EXTINCTION OF SPECIES. [Cn. XLIL 
 
 dates from so recent a period, that we can scarcely trace the 
 advance or decline of any animal or plant, except in those 
 cases where the influence of man has intervened ; yet we can 
 easily conceive what must happen when some new colony of 
 wild animals or plants enters a region for the first time, and 
 succeeds in establishing itself. 
 
 Supposed effects of the first entrance of the polar bear into 
 Iceland. Let us consider how great are the devastations 
 committed at certain periods by the Greenland bears, when 
 they are drifted to the shores of Iceland in considerable num- 
 bers on the ice. These periodical invasions are formidable 
 even to man ; so that when the bears arrive, the inhabitants 
 collect together, and go in pursuit of them with fire-arms- 
 each native who slays one being rewarded by the king of 
 Denmark. The Danes of old, when they landed in their 
 marauding expeditions upon our coast, hardly excited more 
 alarm, nor did our islanders muster more promptly for the 
 defence of their lives and property against the common enemy, 
 than the modern Icelanders against these formidable brutes. 
 It often happens, says Henderson, that the natives are pur- 
 sued by the bear when he has been long at sea, and when 
 his natural ferocity has been heightened by the keenness of 
 hunger ; if unarmed, it is frequently by stratagem only that 
 they make their escape.* 
 
 Let us cast our thoughts back to the period when the first 
 polar bears reached Iceland, before it was colonised by the 
 Norwegians in 874 : we may imagine the breaking up of an 
 immense barrier of ice like that which, in 1816 and the 
 following year, disappeared from the east coast of Greenland, 
 which it had surrounded for four centuries. By the aid of 
 such means of transportation a great number of these quadru- 
 peds might effect a landing at the same time, and the havoc 
 which they would make among the species previously settled 
 in the island would be terrific. The deer, foxes, seals, and 
 even birds, on which these animals sometimes prey, would be 
 soon thinned down. 
 
 But this would be a part only, and probably an insignifi- 
 cant portion, of the aggregate amount of change brought 
 
 * Journal of a Residence in Iceland, p. 27 . 
 
CH. XLIL] HABITS OF EIDER DUCKS IN ICELAND. 449 
 
 about by the new invader. The plants on which the deer fed, 
 being less consumed in consequence of the lessened numbers 
 of that herbivorous species, would soon supply more food to 
 several insects, and probably to some terrestrial testacea, so 
 that the latter would gain ground. The increase of these 
 would furnish other insects and birds with food, so that the 
 numbers of these last would be augmented. The diminution 
 of the seals would afford a respite to some fish which they 
 had persecuted ; and these fish, in their turn, would then 
 multiply and press upon their peculiar prey. Many water- 
 fowls, the eggs and young of which are devoured by foxes, 
 would increase when the foxes were thinned down by 
 the bears ; and the fish on which the water-fowls subsisted 
 would then, in their turn, be less numerous. Thus the 
 numerical proportions of a great number of the inhabitants, 
 both of the land and sea, might be permanently altered 
 by the settling of one new species in the region ; and the 
 changes caused indirectly would ramify through all classes 
 of the living creation, and be almost endless. 
 
 An actual illustration of what we have here only proposed 
 hypothetically, is in some degree afforded by the selection of 
 small islands by the eider duck for its residence during the 
 season of incubation, its nests being seldom if ever found on 
 the shores of the main land, or even of a large island. The 
 Icelanders are so well aware of this, that they have expended 
 a great deal of labour in forming artificial islands, by 
 separating from the main land certain promontories, joined 
 to it by narrow isthmuses. This insular position is necessary 
 to guard against the destruction of the eggs and young birds, 
 by foxes, dogs, and other animals. One year, says Sir W. 
 Hooker, it happened that, in the small island of Vidoe, ad- 
 joining the coast of Iceland, a fox got over upon the ice, and 
 caused great alarm, as an immense number of ducks were then 
 sitting on their eggs or young ones. It was long before he 
 was taken, which was at last, however, effected by bringing 
 another fox to the island, and fastening it by a string near 
 the haunt of the former, by which he was allured within shot 
 of the hunter.* 
 
 * Tour in Iceland, vol. i. p. 64, 2nd edit. 
 VOL. II. G G 
 
450 EXTINCTION OF SPECIES. [Cn. XLII 
 
 Increase of rein-deer imported into Iceland. As an example 
 of the rapidity with which a large tract may become 
 peopled by the offspring of a single pair of quadrupeds, it maj 
 be mentioned that in the year 1773 thirteen rein-deer were 
 exported from Norway, only three of which reached Iceland, 
 These were turned loose into the mountains of Guldbringe 
 Syssel, where they multiplied so greatly, in the course of forty 
 years, that it was not uncommon to meet with herds, consist- 
 ing of from forty to one hundred, in various districts. 
 
 The rein-deer, observes a modern writer, is in Lapland a 
 loser by his connection with man, but Iceland will be this 
 creature's paradise. There is, in the interior, a tract which 
 Sir G. Mackenzie computes at not less than 40,000 square 
 miles, without a single human habitation, and almost en- 
 tirely unknown to the natives themselves. There are no 
 wolves ; the Icelanders will keep out the bears ; and the rein- 
 deer, being almost unmolested by man, will have no enemy 
 whatever, unless it has brought with it its own tormenting 
 gad-fly.* 
 
 Ulloa in his voyage, and Buffon on the authority of old 
 writers, relate a fact which illustrates very clearly the prin- 
 ciple before explained, of the check which the increase of one 
 animal necessarily offers to that of another. The Spaniards 
 had introduced goats into the island of Juan Fernandez, where 
 they became so prolific as to furnish the pirates who infested 
 those seas with provisions. In order to cut off this resource 
 from the buccaneers, a number of dogs were turned loose into 
 the island ; and so numerous did they become in their turn, 
 that they destroyed the goats in every accessible part, after 
 which the number of the wild dogs again decreased.f 
 
 It is usually the first appearance of an animal or plant, in 
 a region to which it was previously a stranger, that gives rise 
 to the chief alteration ; since, after a time, an equilibrium, is 
 again established. But it must require ages before such a 
 new adjustment of the relative forces of so many conflicting 
 agents can be definitely settled. The causes in simultaneous 
 action are so numerous, that they admit of an almost infinite 
 
 * Travels in Iceland in 1810, p. 342. 
 
 t Buffon, vol. v. p. 100. UUoa's Voyage, vol. ii. p. 220. 
 
CH. XLII.l CHANGES CAUSED BY MAX. 451 
 
 number of combinations ; and it is necessary that all these 
 should have occurred once before the total amount of change, 
 capable of flowing from any new disturbing force, can be 
 estimated. 
 
 Thus, for example, suppose that once in two centuries a 
 frost of unusual intensity, or a volcanic eruption of great 
 violence accompanied by floods from the melting of glaciers, 
 should occur in Iceland ; or an epidemic disease, fatal to the 
 larger number of individuals of some one species, and not 
 affecting others, these, and a variety of other contingencies, 
 all of which may occur at once, or at periods separated by 
 different intervals of time, ought to happen before it would 
 be possible for us to declare what ultimate alteration the 
 presence of any new comers, such as the bear or rein-deer 
 before mentioned, might occasion in the animal population of 
 the isle. 
 
 Every new condition in the state of the organic or inorganic 
 creation, a new animal or plant, an additional snow-clad 
 mountain, any permanent change, however slight in compa- 
 rison to the whole, gives rise to a new order of things, and 
 may make a material change in regard to some one or more 
 species. Yet a swarm of locusts, or a frost of extreme inten- 
 sity, or an epidemic disease, may pass away without any 
 great apparent derangement ; no species may be lost, and all 
 may soon recover their former relative numbers, because the 
 same scourges may have visited the region again and again, 
 at preceding periods. Every plant that was incapable of 
 resisting such a degree of cold, every animal which was ex- 
 posed to be entirely cut off by an epidemic or by famine 
 caused by the consumption of vegetation by the locusts, may 
 have perished already, so that the subsequent recurrence of 
 similar catastrophes is attended only by a temporary change. 
 
 Extirpation of species by man. That man is, geologically 
 speaking, of very modern origin we may assume, although we 
 have recently obtained satisfactory proofs that he was con- 
 temporary with the mammoth and many other extinct mam- 
 malia, and that he has survived considerable changes in the 
 physical geography of the globe. 
 
 The number of human beings now peopling the earth is 
 
 G G 2 
 
452 EXTINCTION OF SPECIES. [Cn. XLII. 
 
 generally supposed to amount to eight hundred millions, so 
 that we may easily understand how great a number of beasts 
 of prey, birds, and animals of every class, this prodigious 
 population must have displaced, independently of the still 
 more important consequences which have followed from the 
 derangement brought about by man in the relative numerical 
 strength of particular species. 
 
 It may perhaps be said, that man has, in no small degree, 
 compensated for the appropriation to himself of the food of 
 many animals by artificially improving the natural produc- 
 tiveness of soils, by irrigation, manure, and a judicious inter- 
 mixture of mineral ingredients conveyed from different 
 localities. But it admits of reasonable doubt whether, upon 
 the whole, we fertilise or impoverish the lands which we 
 occupy. This assertion may seem startling to many ; because 
 they are so much in the habit of regarding the sterility or 
 productiveness of land in relation to the wants of man, and 
 not as regards the organic world generally. It is difficult, at 
 first, to conceive, if a morass is converted into arable land, and 
 made to yield a crop of grain, even of moderate abunda-nce, that 
 we have not improved the capabilities of the habitable surface 
 that we have not empowered it to support a larger quantity 
 of organic life. In such cases, however, a tract, before of no 
 utility to man, may be reclaimed, and become of high agri- 
 cultural importance, though it may, nevertheless, yield a 
 scantier vegetation. If a lake be drained, and turned into a 
 meadow, the space will provide sustenance to man, and many 
 terrestrial animals serviceable to him, but not, perhaps, so 
 much food as it previously yielded to the aquatic races. 
 
 The felling of dense and lofty forests, which covered, even 
 within the records of history, a considerable space on the 
 globe, now tenanted by civilised man, must generally have 
 lessened the amount of vegetable food throughout the space 
 where these woods grew. We must also take into our 
 account the area covered by towns, and a still larger surface 
 occupied by roads. 
 
 If we force the soil to bear extraordinary crops one year, 
 we are, perhaps, compelled to let it lie fallow the next. But 
 nothing so much counterbalances the fertilising effects of 
 
dr. XLII.l CHANGES CAUSED BY MAX. 453 
 
 human art as the extensive cultivation of foreign herbs and 
 shrubs, which, although they are often more nutritious to 
 man, seldom thrive with the same rank luxuriance as the 
 native plants of a district. Man is, in truth, continually 
 striving to diminish the natural diversity of the stations of 
 animals and plants in every country, and to reduce them all 
 to a small number fitted for species of economical use. He 
 may succeed perfectly in attaining his object, even though 
 the vegetation be comparatively meagre, and the total 
 amount of animal life be greatly lessened. 
 
 When St. Helena was discovered about the year 1506, 
 it was entirely covered with forests, the trees drooping over 
 the tremendous precipices that overhang the sea. Now, says 
 Dr. Hooker, all is changed ; fully five-sixths of the island 
 are entirely barren, and by far the greater part of the vegeta- 
 tion which exists, whether herbs, shrubs, or trees, consists of 
 introduced European, American, African, and Australian 
 plants, which propagated themselves with such rapidity 
 that the native plants could not compete with them. These 
 exotic species, together with the goats, which being carried 
 to the island destroyed the forests by devouring all the 
 young plants, are supposed to have utterly annihilated about 
 100 peculiar and indigenous species, all record of which is 
 lost to science, except those of which specimens were collected 
 by the late Dr. Burchell and are now in the herbarium of Kew.* 
 
 In the district of Canterbury, New Zealand, Mr. Locke 
 Travers, writing in 1863, says that the spread of European 
 and other foreign plants is surprisingly rapid. The cow-grass 
 (Polygonum aviculare), the common dock, and the sow thistle 
 grow luxuriantly, the water-cress increases in the still rivers 
 so as to threaten to choke them up altogether, and to put the 
 colonists to the expense of 300 annually in keeping open 
 a single stream, the Avon, which runs through Christchurch. 
 Stems of this water-cress have been measured 12 feet long 
 and three quarters of an inch in diameter. In some mountain 
 districts the white clover is displacing the native grasses, and 
 foreign trees, such as poplars, and willows, and the gum- 
 
 * Hooker, Insular Floras, Brit. Assoc. Nottingham, ] 866. 
 
454 EXTINCTION OF SPECIES. [Cn. XLII. 
 
 trees of Australia, are growing rapidly. In fact, the young 
 native vegetation appears to shrink from competition with 
 these more vigorous intruders.'"* 
 
 Spix and Martius have given a lively description of the 
 incredible number of insects which lay waste the crops in 
 Brazil, besides swarms of monkeys, flocks of parrots, and 
 other birds, as well as the paca, agouti, and wild swine. 
 They describe the torment which the planter and the natura- 
 list suffer from the musquitoes, and the devastation of the 
 ants and blattse ; they speak of the dangers to which they were 
 exposed from the jaguar, the poisonous serpents, crocodiles, 
 scorpions, centipedes, and spiders. But with the increasing 
 population and cultivation of the country, say these natura- 
 lists, these evils will gradually diminish ; when the inhabitants 
 have cut down the woods, drained the marshes, made roads 
 in all directions, and founded villages and towns, man will, 
 by degrees, triumph over the rank vegetation and the noxious 
 animals, and all the elements will second and amply recom- 
 pense his activity, f 
 
 Indigenous quadrupeds and birds extirpated in Great Britain. 
 Let us make some enquiries into the extent of the influence 
 which the progress of society has exerted during the last 
 seven or eight centuries, in altering the distribution of 
 indigenous British animals. Dr. Fleming, in an able memoir 
 on the subject, has enumerated the best authenticated 
 examples of the decrease or extirpation of certain species 
 during a period when our population has made the most 
 rapid advances. I shall offer a brief outline of his results. J 
 
 The stag, as well as the fallow deer and the roe, were 
 formerly so abundant in our island, that, according to Lesley, 
 from five hundred to a thousand were slain at a hunting- 
 match ; but the native races would already have been ex- 
 tinguished, had they not been carefully preserved in certain 
 forests. The otter, the marten, and the polecat were also in 
 sufficient numbers to be pursued for the sake of their fur ; 
 but they have now been reduced within very narrow bounds. 
 
 * Locke Travers, cited by Hooker, $ Ed. Phil. Journ., No. xxii. p. 287. 
 
 Nat. Hist. Kev. 1864, p. 124. Oct. 1824. 
 
 f Travels in Brazil, vol. i. p. 260. 
 
CH. XLIL] CHANGES CAUSED BY MAN. 455 
 
 The wild cat and fox have also been sacrificed throughout 
 the greater part of the country, for the security of the poultry- 
 yard or the fold. Badgers have been expelled from nearly 
 every district, which at former periods they inhabited. 
 
 Besides these, which have been driven out from their 
 favourite haunts, and everywhere reduced in number, there 
 are some which have been wholly extirpated ; such as the 
 ancient breed of indigenous horses, and the wild boar ; of 
 the wild oxen a few remains are still preserved in some of 
 the old English parks. The beaver, which is eagerly sought 
 after for its fur, had become scarce at the close of the ninth 
 century ; and, by the twelfth century, was only to be met 
 with, according to Giraldus de Barri, in one river in Wales, 
 and another in Scotland. The wolf, once so much dreaded 
 by our ancestors, is said to have maintained its ground in 
 Ireland so late as the beginning of the eighteenth century 
 (1710), though it had been extirpated in Scotland thirty years 
 before, and in England at a much earlier period. The bear, 
 which, in Wales, was regarded as a beast of chase equal to 
 the hare or the boar, only perished, as a native of Scotland, 
 in the year 1057.* 
 
 Many native birds of prey have also been the subjects of 
 unremitting persecution. The eagles, larger hawks, and 
 ravens, have disappeared from the more cultivated districts. 
 The haunts of the mallard, the snipe, the redshank, and the 
 bittern, have been drained equally with the summer dwellings 
 of the lapwing and the curlew. But these species still linger 
 in some portion of the British Isles ; whereas the larger 
 capercailzies, formerly natives of the pine-forests of Ireland 
 and Scotland, had been quite destroyed towards the close 
 of the last century, but were successfully reintroduced into 
 Perthshire about the year 1824. The egret and the crane, 
 which appear to have been formerly very common in Scot- 
 land, are now only occasional visitants. f 
 
 The bustard (Otis tar da), observes Graves, in his British 
 Ornithology, J f was formerly seen on the downs and heaths 
 
 * Fleming, Ed. Phil. Journ. Xo. xxii. t Fleming, ibid., p. 292. 
 
 p. 295. | Vol. iii. London, 1821. 
 
45G EXTINCTION OF SPECIES. [Cn. XLII. 
 
 of various parts of our island, in flocks of forty or fifty birds ; 
 whereas it is now (1821) a circumstance of rare occurrence 
 to meet with a single individual.' Bewick also remarks, 
 6 that they were formerly more common in this island than 
 at present ; they are now found only in the open counties of 
 the south and east in the plains of Wiltshire, Dorsetshire, 
 and some parts of Yorkshire.'* In the few years that have 
 elapsed since Bewick wrote, this bird has entirely disappeared 
 from the British Isles. These changes, it may be obseryed, 
 are derived from very imperfect memorials, and relate only to 
 the larger and more conspicuous animals inhabiting a small 
 spot on the globe ; but they cannot fail to exalt our conception 
 of the enormous revolutions which, in the course of thousands 
 of years, the whole human species must have effected. 
 
 Extinction of the dodo. The kangaroo and the emu are 
 retreating rapidly before the progress of colonisation in 
 Australia ; and it scarcely admits of doubt, that the general 
 cultivation of that country must lead to the extirpation of both. 
 The most striking example of the loss, even within the last two 
 centuries, of a remarkable species, is that of the dodo a bird 
 first seen by the Dutch, when they landed on the Isle of France, 
 at that time uninhabited, immediately after the discovery of 
 the passage to the East Indies by the Cape of Good Hope. It 
 was of a large size, and singular form; its wings short, like 
 those of an ostrich, and wholly incapable of sustaining its 
 heavy body, even for a short flight. In its general appearance 
 it differed from the ostrich, cassowary, or any known bird.f 
 
 Many naturalists gave figures of the dodo after the com- 
 mencement of the seventeenth century ; and there is a 
 painting of it in the British Museum, which is said to have 
 been taken from a living individual. Beneath the painting 
 
 * Land Birds, vol. i. p. 316, ed. 1821. University of Oxford, the exact day and 
 
 f Some have complained thatinscrip- year when the remains of the last speei- 
 
 tions on tomb-stones convey no general men of the dodo, which had been per- 
 
 information, except that individuals were mitted to rot in the Ashmolean Museum, 
 
 born and died, accidents which must were ca^t away. The relics, we are told, 
 
 happen alike to all men. But the death were ' a rnusseo subducta, annuente vice- 
 
 of a specks is so remarkable an event in cancellario aliisque curatoribus, ad ea 
 
 natural history that it deserves comme- lustranda convocatis, die Januarii 8vo, 
 
 moration, and it is with no small interest A.D. 1755.' Zool. Journ. No. 12, p. 559, 
 
 that we learn, from the archives of the 1828. 
 
CH.XLIL] EXTINCTION OF THE DODO. 457 
 
 is a leg, in a fine state of preservation, which ornithologists 
 are agreed cannot belong to any other known bird. In the 
 museum at Oxford, also, there is a foot and a head in an 
 imperfect state. 
 
 In spite of the most active search, during the last century, 
 no information respecting the dodo was obtained, and some 
 authors went so far as to pretend that it had never existed ; 
 but a great mass of satisfactoiy evidence in favour of its 
 recent existence has now been collected by Mr. Broderip,* 
 and by Mr. Strickland and Dr. Melville. Mr. Strickland, 
 agreeing with Professor Eeinhardt, of Copenhagen, in re- 
 ferring the dodo to the Columbidse, calls it a e vulture-like 
 frugiverous pigeon.' It appears, also, that another short- 
 winged bird of the same order, called ' The Solitaire/ 
 inhabited the island of Rodrigues, 300 miles east of the 
 Mauritius, and has been exterminated by man, as have one 
 or two different but allied birds of the Isle of Bourbon. f In 
 the year 1865 parts of the skeleton of the dodo were dug up 
 in a bog near the sea in the island of Mauritius. They were 
 sent to Professor Owen, and were described by him in the 
 Transactions of the Zoological Society for 1867. Speaking of 
 the extinct bird as the great ( ground-dove ' of the Mauritius, 
 he speculates on this peculiar species having originated in 
 that uninhabited and thickly wooded island, where there was 
 no animal powerful enough to contend with it and from which 
 it would be required to escape by flight. He therefore con- 
 ceives that c finding food enough scattered over the ground, it 
 ceased to exert its wings in raising the heavy trunk, and so 
 gradually gained bulk in the course of many generations. 
 Hence the organs of flight would, according to Lamarckian 
 principles, be atrophied by disease and diminished in size and 
 strength, while the hind limbs, having an increasing weight 
 to support and being exercised by habitual motion on the 
 land, would acquire larger dimensions. 5 J 
 
 Rapid propagation of domestic quadrupeds over the American 
 continent. Next to the direct agency of man, his indirect 
 influence in multiplying the numbers of large herbivorous 
 
 * Penny Cyclopaedia, ' Dodo,' 1837. 'the Dodo and its Kindred.' London, 
 t Messrs. Strickland and Melville on 1848. 
 
458 EXTINCTION OF SPECIES. [Cii. XLII. 
 
 quadrupeds of domesticated races may be regarded as one of 
 the most obvious causes of the extermination of species. On 
 this, and on several other grounds, the introduction of the 
 horse, ox, and other mammalia, into America, and their 
 rapid propagation over that continent within the last three 
 centuries, is a fact of great importance in natural history. 
 The extraordinary herds of wild cattle and horses which 
 overran the plains of South America sprung from a very few 
 pairs first carried over by the Spaniards ; .and they prove 
 that the wide geographical range of large species in great 
 continents does not necessarily imply that they have existed 
 there from remote periods. 
 
 Humboldt observes, in his Travels, on the authority of 
 Azara, that it is believed that there exist, in the Pampas of 
 Buenos Ayres, twelve million cows and three million horses, 
 without comprising in this enumeration the cattle that have 
 no acknowledged proprietor. In the Llanos of Caraccas, the 
 rich hateros, or proprietors of pastoral farms, are entirely 
 ignorant of the number of cattle they possess. The young 
 are branded with a mark peculiar to each herd, and some of 
 the most wealthy owners mark as many as 14,000 a year.* 
 In the northern plains, from the Orinoco to the lake of 
 Maracaybo, M. Depons reckoned that 1,200,000 oxen, 180,000 
 horses, and 90,000 mules, wandered at large. f In some 
 parts of the valley of the Mississippi, especially in the country 
 of the Osage Indians, wild horses were immensely numerous 
 in the early part of this century. 
 
 The establishment of black cattle in America dates from 
 Columbus's second voyage to St. Domingo. They there mul- 
 tiplied rapidly ; and that island presently became a kind of 
 nursery from which these animals were successively trans- 
 ported to various parts of the continental coast, and from 
 thence into the interior. Notwithstanding these numerous 
 exportations, in twenty-seven years after the discovery of the 
 island, herds of 4,000 head, as we learn from Oviedo, were 
 not uncommon, and there were even some that amounted to 
 8,000. In 1587, the number of hides exported from St. 
 
 * Pers. Nar. vol. iv. f Quarterly Review, vol. xxi. p. 335. 
 
Cu. XLII.J CHANdKS CAUSED BY MAX. -i.Vj 
 
 Domingo alone, according to Acosta's report, was 35,444; 
 and in the same year there were exported 64,350, from 
 the ports of New Spain. This was in the sixty-fifth year 
 after the taking of Mexico, previous to which event the 
 Spaniards, who came into that country, had not been able to 
 engage 'in anything else than war."* Everyone is aware that 
 these animals are now established throughout the American 
 continent from Canada to the Straits of Magellan. 
 
 The ass has thriven very generally in the New World ; and 
 we learn from Ulloa, that in Quito they ran wild, and multi- 
 plied in amazing numbers, so as to become a nuisance. They 
 grazed together in herds, and when attacked defended them- 
 selves with their mouths. If a horse happened to stray into 
 the places where they fed, they all fell upon him, and did not 
 cease biting and kicking till they left him dead.f This fact 
 illustrates the power of one of those barriers namely, that of 
 preoccupancy, which we before alluded to (p. 351) as being 
 often most effective in limiting the range of species. 
 
 The first hogs were carried to America by Columbus, and 
 established in the island of St. Domingo the year following 
 its discovery, in November, 1493. In succeeding years they 
 were introduced into other places where the Spaniards settled 
 and, in the space of half a century, they were found esta- 
 blished in the New World, from the latitude of 25 north, to 
 the 40th degree of south latitude. Sheep, also, and goats 
 have multiplied enormously in the New World, as have also 
 the cat and the rat ; which last, as before stated, has been 
 imported unintentionally in ships. The dogs introduced by 
 man which have at different periods become wild in America, 
 hunted in packs, like the wolf and the jackal, destroying not 
 only hogs, but the calves and foals of the wild cattle and 
 horses. 
 
 Besides the quadrupeds above enumerated, our domestic 
 fowls have also thriven in the West Indies and America, 
 where they have now the common fowl, the goose, the duck, 
 the peacock, the pigeon, and the guinea-fowl. As these were 
 often taken suddenly from the temperate to very hot regions, 
 
 * Quarterly Review, vol. xxi. p. 335. 
 
 t Ulloa's Voyage. Wood's Zoog. vol. i. p. 9. 
 
4GO EXTINCTION OF SPECIES. [Cn. XLII. 
 
 they were not reared at first without much, difficulty ; but 
 after a few generations, they became habituated to the cli- 
 mate, which, in many cases, approached much nearer than 
 that of Europe to the temperature of their original native 
 countries. The fact of so many millions of wild and tame 
 individuals of our domestic species, almost all of them the 
 largest quadrupeds and birds, having been propagated 
 throughout the new continent within the short period that 
 has elapsed since the discovery of America,' while no appre- 
 ciable improvement can have been made in the productive 
 powers of that vast continent, affords abundant evidence of 
 the extraordinary changes which accompany the diffusion 
 and progressive advancement of the human race over the 
 globe. 
 
 Power of exterminating species no prerogative of man. When 
 we reflect how many millions of square miles of the fertile 
 land, occupied originally by a boundless variety of animal 
 and vegetable forms, have been already brought under the 
 dominion of man, and compelled, in a great measure, to yield 
 nourishment to him, and to a limited number of plants and 
 animals which he has caused to increase, we must at once be 
 convinced, that the annihilation of a multitude of species has 
 already been effected, and will continue to go on hereafter, in 
 certain regions, in a still more rapid ratio, as the colonies of 
 highly civilised nations spread themselves over unoccupied 
 lands. 
 
 Yet, if we wield the sword of extermination as we advance, 
 we have no reason to repine at the havoc committed, nor to 
 fancy, with the Scottish poet, that we violate the social 
 union of nature ; ' or complain, with the melancholy Jacques, 
 that we 
 
 Are mere usurpers, tyrants, and what's worse, 
 To fright the animals and to kill them up 
 In their assign'd and native dwelling-place. 
 
 We have only to reflect, that in thus obtaining possession 
 of the earth by conquest, and defending our acquisitions by 
 force, we exercise no exclusive prerogative. Every species 
 which has spread itself from a small point over a wide area 
 must, in like manner, hare marked its progress by the dimi- 
 
CH. XLIL] CONCLUDING REMARKS ON EXTINCTION. 461 
 
 nution or the entire extirpation of some other, and must 
 maintain its ground by a successful struggle against the 
 encroachments of other plants and animals. That minute 
 parasitic plant, called ' the rust ' in wheat, has, like the Hes- 
 sian fly, the locust, and the aphis, caused famines ere now 
 amongst the f lords of the creation.' The most insignificant and 
 diminutive species, whether in the animal or vegetable king- 
 dom, have each slaughtered their thousands, as they dissemi- 
 nated themselves over the globe, as well as the lion, when 
 first it spread itself over the tropical regions of Africa. 
 
 Concluding remarks mi extinction. From what has now been 
 said of the effect of changes which are always going on in the 
 condition of the habitable surface of the globe, and the 
 manner in which some species are constantly extending their 
 range at the expense of others^ it may be deduced, as a co- 
 rollary, that the species existing at any particular period, 
 must, in the course of ages, become extinct one after the 
 other. ' They must die out,' to borrow an emphatical expres- 
 sion from Buffon, ' because Time fights against them.' 
 
 If such then be a law of the organic world, if every species 
 is continually losing some of its varieties and every genus 
 some of its species, it follows that the transitional links which 
 once, according to the doctrine of Transmutation, must have 
 existed, will, in the great majority of cases, be missing. We 
 learn from geological investigations that throughout an inde- 
 finite lapse of ages the whole Animate creation has been 
 decimated again and again. Sometimes a single representa- 
 tive alone remains of a type once dominant, or of which the 
 fossil species may be reckoned by hundreds. We rarely find 
 that whole orders have disappeared, yet even this is notably 
 the case in the class of reptiles, which has lost some orders 
 characterised by a higher organisation than any now surviving 
 in that class. Certain genera of plants and animals which 
 seem to have been wholly wanting, and others which were 
 feebly represented, in the Tertiary Period, are now rich in 
 species, and appear to be in such perfect harmony with the 
 present conditions of existence, that they present us with 
 countless varieties confounding the zoologist or botanist who 
 undertakes to describe and classify them. 
 
462 EXTINCTION OF SPECIES. [Cn. XLIL 
 
 We have only to reflect on the causes of extinction enume- 
 rated in this chapter, and we at once foresee the time when 
 even in these genera so many gaps will occur, so many tran- 
 sitional forms will be lost, that there will no longer be any 
 difficulty in assigning definite limits to each species. The 
 blending therefore of one general or specific form into an- 
 other, must be an exception to the general rule, whether 
 in our own times or at any period of the past, because the 
 forms surviving at any given moment will have been exposed 
 for a long succession of antecedent periods to those powerful 
 causes of extinction which are slowly, but incessantly, at 
 work in the organic and inorganic worlds. 
 
 Dr. Hooker, in commenting on the loss of a hundred species 
 of plants in the course of the last three and a half centuries 
 in St. Helena,* remarks, ' every one of these species was a 
 link in the chain of created beings, which contained within 
 itself evidence of the affinities of other species both living 
 and extinct, but which evidence is now irrecoverably lost.' 
 
 It is affirmed by Darwin that genera which in the present 
 state of the globe are most dominant contain also the most 
 variable species. It is in such genera that the formation of 
 new races, or f incipient species,' is most actively going on ; 
 whereas in the majority of more ancient genera and families 
 species are fast dying out ; and that such has always been the 
 order of Nature is proved by the fact, that while certain forms 
 are characteristic of every geological period, these same are 
 unknown or feebly represented, whether in older strata or 
 in formations of later date. 
 
 They who imagine that if the theory of Transmutation be 
 true we ought to discover in a fossil state all the intermediate 
 links by which the most dissimilar types have been formerly 
 connected together must tacitly assume that it is part of 
 the pla.n of Nature to leave to after ages permanent records 
 of all her works, whether animal or vegetable. Yet these 
 same objectors to the theory would hardly expect that the 
 species of plants just alluded to as having been so recently 
 extirpated in St. Helena have all of them left memorials of 
 
 * See above, p. 453. 
 
CH. XLIL] CONCLUDING EEMARKS ON EXTINCTION. 463 
 
 their existence in the crust of the earth. In Chapter XIY. 
 I have treated of the fragmentary nature of the geological 
 record,* re-affirming what I first stated in 1833, that it is 
 scarcely possible to exaggerate the defectiveness of our 
 archives. These records, like the existing species, are con- 
 stantly wasting away before our eyes, while new deposits, 
 containing the partial memorials of the modern fauna and 
 flora, are now in the process of formation. But as the new 
 strata are deposited out of sight, chiefly in the basins of seas 
 and lakes, their origin is not so conspicuous as is the de- 
 struction of the memorials of older date. 
 
 So also, as before stated (p. 269), the dying out of old forms is 
 more easily proved than the coming in of new ones. We might 
 see in a large forest a full-grown tree blown down or felled by 
 the axe every day in the year, and yet at the end of fifty years 
 find that the number and size of the. trees in the forest was 
 the same as before, because the daily growth of timber spread 
 over many thousands of trees, though insensible to the eye, 
 may every day produce a quantity of foliage and timber equal 
 in the aggregate to that contained in a single full-grown 
 tree. In like manner, if one species die out annually, as 
 before hinted (p. 272), the loss may be compensated by 
 the amount of permanent change effected by Variation and 
 Natural Selection, in the course of a single year, among 
 thousands of species. 
 
 * Vol. I. pp. 317-320. 
 
464 
 
 CHAPTER XLIII. 
 
 MAN CONSIDERED WITH REFERENCE TO HIS ORIGIN AND 
 GEOGRAPHICAL DISTRIBUTION. 
 
 GEOGRAPHICAL DISTRIBUTION OF THE RACES OF MAN DRIFTING OF CANOES 
 TO VAST DISTANCES MAN, LIKE OTHER SPECIES, HAS SPREAD FROM A SINGLE 
 STARTING-POINT, OR LIMITED AREA WHETHER MAN'S BODILY FRAME BE- 
 CAME MORE STATIONARY WHEN HIS MIND BECAME MORE ADVANCED GREAT 
 ANTIQUITY OF THE MORE MARKED HUMAN RACES GENERAL COINCIDENCE 
 OF THEIR RANGE WITH THE GREAT ZOOLOGICAL PROVINCES AMERICAN- 
 INDIAN COMMON TO NEOARCTIC AND NEOTROPICAL REGIONS MAN AN OLD- 
 WORLD TYPE MARKED LINE OF SEPARATION BETWEEN MALAYAN AND 
 
 PAPUAN RACES DISTINCTNESS OF NEGRO AND EUROPEAN, AND QUESTION OF 
 
 THE MULTIPLE ORIGIN OF MAN SIX-FINGERED VARIETY OF MAN AS BEARING - 
 
 ON THE MUTABILITY OF HIS ORGANISATION REGROWTH OF SUPERNUMERARY 
 DIGITS WHEN AMPUTATED THESE PHENOMENA REFERRED BY DARWIN TO 
 
 REVERSION WHETHER MAN HAS BEEN DEGRADED FROM A HIGHER OR HAS 
 
 RISEN FROM A LOWER STAGE OF CIVILISATION GRADUAL DIMINUTION OF 
 THE NUMBER OF LANGUAGES AND RACES GAUDRY ON INTERMEDIATE FORMS 
 
 BETWEEN THE UPPER MIOCENE AND THE LIVING MAMMALIA RELATIONSHIP 
 
 OF MIOCENE AND LIVING QUADRUMANA OWEN'S CLASSIFICATION OF MAM- 
 MALIA ACCORDING TO CEREBRAL DEVELOPMENT PROGRESSIVE ADVANCEMENT 
 
 IN CEREBRAL CAPACITY OF THE VERTEBRATA IMPROVEMENT OF MAN'S 
 
 CEREBRAL CONFORMATION WHETHER THERE IS ANY FIXED LAW OF PRO- 
 GRESS OBJECTIONS TO DARWIN*S THEORY OF NATURAL SELECTION CON- 
 SIDERED GREAT STEP GAINED IF SPECIES ARE SHOWN TO BE DEVELOPED 
 ACCORDING TO THE ORDINARY LAWS OF REPRODUCTION CAUSE OF RELUC- 
 TANCE TO BELIEVE IN MAN'S DERIVATIVE ORIGIN. 
 
 GEOGRAPHICAL DISTRIBUTION OF THE RACES OF MAN. 
 In this chapter I shall offer some observations on the geo- 
 graphical distribution of the different races of man, and con- 
 sider whether if we admit the doctrine of Transmutation as 
 most probable in the case of the inferior mammalia, we are 
 bound to embrace the same hypothesis when speculating on 
 the origin of the human species. 
 
 Long before the geologist had succeeded in tracing back 
 the signs of man's existence to a time when Europe was in- 
 habited by species of quadrupeds, such as the elephant, 
 
CH. XLIIL] ORIGIN AND DISTRIBUTION OF MAN. IC.,") 
 
 rhinoceros, bear, lion, hytena, and others long since extinct, 
 naturalists had already amused themselves in speculating on 
 the probable birthplace of mankind, the point from which, 
 if we assume the whole human race to have descended from 
 a single stock, the tide of emigration must originally have 
 proceeded. It has been always a favourite conjecture, that 
 this birthplace was situated within or near the tropics, where 
 perpetual summer reigns, and where fruits, herbs, and roots 
 are plentifully supplied throughout the year. The climate 
 of these regions, it has been said, is suited to a being born 
 without any covering, and who had not yet acquired the arts 
 of building habitations or providing clothes. 
 
 ' The hunter state,' it has been argued, ' which Montes- 
 quieu placed the first, was probably only the second stage to 
 which mankind arrived ; since so many arts must have been 
 invented to catch a salmon, or a deer, that society could no 
 longer have been in its infancy when they came into use.'* 
 When regions where the spontaneous fruits of the earth 
 abound became overpeopled, men would naturally diffuse 
 themselves over the neighbouring parts of the temperate 
 zone ; but a considerable time would probably elapse before 
 this event took place ; and it is possible, as a writer before 
 cited observes, that in the interval before the multiplication 
 of their numbers and their increasing wants had compelled 
 them to emigrate, some arts to take animals were invented, 
 but far inferior to what we see practised at this day among 
 savages. As their habitations gradually advanced into the 
 temperate zone, the new difficulties they had to encounter 
 would call forth by degrees the spirit of invention, and the 
 probability of such inventions always rises with the number 
 of people involved in the same necessity.f 
 
 Sir Humphry Davy, although coinciding for the most part 
 in the above views, has introduced one of the persons in his 
 second dialogue, as objecting to the theory of the human race 
 having gradually advanced from a savage to a civilised state, 
 on the ground that ' the first man must have inevitably been 
 destroyed by the elements or devoured by savage beasts, so 
 
 'isscrt. from the Amcen. Acad., vol.i. p. 118. t Ibid. 
 
 VOL. II. H H 
 
4G6 ORIGIN AND DISTRIBUTION OF MAN. [Cn. XLIIL 
 
 infinitely his superiors in physical force. '* But this difficulty 
 had been met, as before stated, by assigning, as the original 
 seat of man, some island within the tropics, free from large 
 beasts of prey. Here man may have remained for a period, 
 peculiar to a limited area, just as some of the large anthro- 
 pomorphous species are now restricted to one tropical island. 
 In such a situation, the new-born race might have lived in 
 security, though far more helpless than the New Holland 
 savages, and might have found abundance of vegetable food. 
 Colonies may afterwards have been sent forth from this 
 mother country, and then the peopling of the earth may have 
 proceeded according to the hypothesis before alluded to. 
 
 In an early stage of society the necessity of hunting acts 
 as a principle of repulsion, causing men to spread with the 
 greatest rapidity over a country, until the whole is covered 
 with scattered settlements. It has been calculated that 
 800 acres of hunting-ground produce only as much food as 
 half an acre of arable land. When the game has been in 
 a great measure exhausted, and a state of pasturage suc- 
 ceeds, the several hunter-tribes, being already scattered, may 
 multiply in a short time into the greatest number which the 
 pastoral state is capable of sustaining. The necessity, says 
 Brand, thus imposed upon the two savage states, of dispersing 
 themselves far and wide over the country, affords a reason 
 why, at a very early period, the worst parts of the earth may 
 have become inhabited. 
 
 But this reason, it may be said, is only applicable in as far 
 as regards the peopling of a continuous continent ; whereas 
 the smallest islands, however remote from continents, have 
 almost always been found inhabited by man. St. Helena, it 
 is true, afforded an exception ; for when that island was dis- 
 covered in 1501, it was only inhabited by sea- fowl, and occa- 
 sionally visited by seals and turtles, f The islands also of 
 Madeira, Mauritius, Bourbon, Pitcairns, and Juan Fernandez, 
 and those of the. Galapagos archipelago, one of which is 
 70 miles long, were uninhabited when first discovered, as 
 were also the Falkland Islands, which is still more remark- 
 
 * Sir H. Davy, Consolations in Travel, p. 74. t See p. 453. 
 
CH. XLIIL] DRIFTING OF CANOES TO VAST DISTANCES. 467 
 
 able, since they are together 120 miles in length by 60 in 
 breadth, and abound in food fit for the support of man. 
 
 Drifting of canoes to vast distances. Very few of the nume- 
 rous coral islets and volcanos of the vast Pacific, capable of 
 sustaining a few families of men, have been found unten- 
 anted ; and we have, therefore, to enquire whence and by what 
 means, if all the members of the great human family have 
 had one common source, could those savages have migrated. 
 Captain Cook, Mr. Forster, and others, have remarked that 
 parties of savages in their canoes must have often lost their 
 way, and must have been driven on distant shores, where 
 they were forced to remain, deprived both of the means and 
 of the requisite intelligence for returning to their own 
 country. Thus Cook found on the island of Wateoo three in- 
 habitants of Otaheite, who had been drifted thither in a canoe, 
 although the distance between the two isles is 550 miles. 
 In 1696, two canoes, containing thirty persons, who had left 
 Ancorso, were thrown by contrary winds and storms on the 
 island of Samar, one of the Philippines, at a distance of 800 
 miles. In 1721, two canoes, one of which contained twenty- 
 four, and the other six persons, men, women, and children, 
 were drifted from an island called Farroilep to the island of 
 Guaham, one of the Marians, a distance of 200 miles.* 
 
 Kotzebue, when investigating the Coral Isles of Radack ? 
 at the eastern extremity of the Caroline Isles, became ac- 
 quainted with a person of the name of Kadu, who was a 
 native of Ulea, an isle 1,500 miles distant, from which he had 
 been drifted with a party. Kadu and three of his country- 
 men one day left Ulea in a sailing boat, when a violent storm 
 arose, and drove them out of their course : they drifted 
 about the open sea for eight months, according to their 
 reckoning by the moon, making a knot on a cord at every 
 new moon. Being expert fishermen, they subsisted entirely 
 on the produce of the sea ; and when the rain fell, laid in as 
 much fresh water as they had vessels to contain it. ' Kadu/ 
 says Kotzebue, ' who was the best diver, frequently went down 
 ;o the bottom of the sea, where it is well known that the 
 
 * Malte-Brun's Geography, vol. iii. p. 419. 
 
 H H 2 
 
468 ORIGIN AND DISTRIBUTION OF MAN. [Cn. XLIII. 
 
 water is not so salt., with a cocoa-nut shell, with only a small 
 opening.' * When these unfortunate men reached the isles 
 of Badack, every hope and almost every feeling had died 
 within them ; their sail had long been destroyed, their canoe 
 had long been the sport of winds and waves, and they were 
 picked up by the inhabitants of Aur in a state of insensibility ; 
 but by the hospitable care of those islanders they soon re- 
 covered, and were restored to perfect health. f 
 
 Captain Beechey, in his voyage to the Pacific, fell in with 
 some natives of the Coral Islands, who had in a similar 
 manner been carried to a great distance from their native 
 country. They had embarked, to the number of 150 souls, in 
 three double canoes, from Anaa, or Chain Island, situated 
 about 300 miles to the eastward of Otaheite. They were 
 overtaken by the monsoon, which dispersed the canoes ; and 
 after driving them about the ocean, left them becalmed, so 
 that a great number of persons perished. Two of the canoes 
 were never heard of; but the other was drifted from one 
 uninhabited island to another, at each of which the voyagers 
 obtained a few provisions ; and at length, after having wan- 
 dered for a distance of 600 miles, they were found and carried 
 to their home in the Blossom. J 
 
 Mr. Crawfurd informs me that there are several well- 
 authenticated accounts of canoes having been drifted from 
 Sumatra to Madagascar, and by such causes a portion of the 
 Malayan language, with some useful plants, have been trans- 
 ferred to that island, which is principally peopled by negroes. 
 
 The space traversed in some of these instances was so great, 
 that similar accidents might suffice to transport canoes from 
 various parts of Africa to the shores of South America, or 
 from Spain to the Azores, and thence to North America ; so 
 that man, even in a rude state of society, is liable to be scat- 
 tered involuntarily by the winds and waves over the globe, in 
 a manner singularly analogous to that in which many plants 
 
 * Chamisso states that the water f Kotzeblie's Voyage, 1815-1818 
 
 which they brought up was cooler, and Quarterly Review, vol. xxvi: p. 361. 
 
 in their opinion, less salt. It is difficult J Narrative of a Voyage to th( 
 
 to conceive its being fresher near the Pacific, &c., in the years 1825, 1826 : ; 
 
 bottom, except where submarine springs 1827, 1828, p. 170. 
 may happen to rise. 
 
L'n. XLIII.] OKKHX AND DISTEIBUTION OF .MAN. 4G ( J 
 
 and animals are diffused. We ought not, then, to wonder, 
 that during the ages required for some tribes of the human 
 nice to attain that advanced stage of civilisation which em- 
 powers the navigator to cross the ocean in all directions with 
 security, the whole earth should have become the abode of 
 rude tribes of hunters and fishers. Were the whole of man- 
 kind now cut off, with the exception of one family, inhabit- 
 ing the old or new continent, or Australia, or even some coral 
 islet of the Pacific, we might expect their descendants, though 
 they should never become more enlightened than the Austra- 
 lians, the South Sea Islanders, or the Esquimaux, to spread 
 in the course of ages over the whole earth, diffused partly by 
 the tendency of population to increase, in a limited district, 
 beyond the means of subsistence, and partly by the accidental 
 drifting of canoes by tides and currents to distant shores. 
 
 Man has spread from a single starting-point. The close 
 affinity of all the races of mankind in their bodily conforma- 
 tion and in their mental and moral attributes, and the manner 
 in which the most divergent varieties intermarry and blend 
 together, requires us to believe that the species was essen- 
 tially in all its characters what it now is before it began to be 
 diffused in the manner above supposed. The more we study 
 the relations of man to the rest of the organic world, the 
 more complete do we find his subjection to the same general 
 laws. If, therefore, we infer that every species of animal has 
 had a single birthplace, it is natural to expect that we shall 
 find that man is no exception to the rule, and that he also 
 spread over all the continents and islands from a single 
 starting-point. But it does not follow that all are descendants 
 of a single pair. Indeed, if we embrace the doctrine of 
 Transmutation, the process by which a new species comes into 
 being is by no means simple, and it is not easy to form a 
 precise idea of its elaboration during that period of transition 
 when certain varieties tending in a given direction are re- 
 peatedly getting the better of others in the struggle for life. 
 Under the const ant influence of the same external conditions, 
 the characters of such varieties become intensified during 
 many successive generations, and when at last they are fixed 
 and permanent the ancestral type may have perished, or in 
 
470 OKHHN AND DISTRIBUTION OF MAN. [On. XLIII. 
 
 some cases may survive in certain stations, the intermediate 
 forms having been absorbed into one or other of the two 
 extremes. During a period when the powers of Variation 
 and Selection are so active, a considerable number of in- 
 dividuals closely allied in their organisation will intermarry 
 freely and multiply within a limited geographical area, and 
 will transmit the same peculiarities of bodily and mental 
 structure to their offspring. When, by this process, a large 
 homogeneous population has been formed, and their characters 
 have become fixed by inheritance, it will be long before sub- 
 sequent changes of climate, soil, foo.d, and other conditions, 
 and, in the case of man, customs and institutions, will cause 
 any marked deviations from the normal type. 
 
 That it should be so difficult for us to picture to ourselves 
 the manner in which a species may be elaborated by Varia- 
 tion and Selection, need not surprise us when we consider 
 how hard it is to obtain a clear idea of the growth and estab- 
 lishment of a new language, even when we are sure that the 
 same has originated only a few centuries before our time. 
 In the case of the English tongue, for example, it would not 
 be easy to fix upon the exact year or generation when it was 
 formed, or to follow it through its various transitional phases 
 when the Anglo-Saxon stock was becoming modified by incor- 
 porating into it French, Danish, and Latin terms and idioms, 
 or when new modes of pronunciation were coming into vogue 
 or new and original expressions invented. The unity and per- 
 manency of character which finally sprang out of the blend- 
 ing together of such heterogeneous materials is a singular 
 phenomenon, and the want of pliancy of the same language 
 when transplanted into distant regions is also remarkable. 
 The modifiability of the language and its tendency to vary 
 never ceases, so that it would readily run into new dialects 
 and modes of pronunciation if there were no communication 
 with the mother country direct or indirect. In this respect its 
 mutability will resemble that of species, and it can no more 
 spring up independently in separate districts than species 
 can, assuming that these last are all of derivative origin. 
 
 Whether man's bodily frame became more stationary when his 
 mind became more advanced. Mr. Wallace, when commenting 
 
 
CH. XLIII.] SLOW FORMATION OF RACKS. 471 
 
 on the distinctness of the leading races of mankind, especially 
 the Caucasian and Negro, and on the constancy of characters 
 maintained by these last for 4,000 years as proved by old 
 Egyptian paintings, suggests that at some former period man's 
 corporeal frame must have been more pliant and variable 
 than it is now ; for according to the observed rate of fluctu- 
 ation in modern times, scarcely any conceivable lapse of ages 
 would suffice to give rise to such an amount of differentiation. 
 He therefore concludes that when first the mental and moral 
 qualities of man acquired predominance his bodily form ceased 
 to vary. He was enabled to meet all new exigencies springing 
 out of new conditions of existence by inventing new weapons, 
 by clothing himself and building houses to protect him 
 against the inclemency of the weather, by making use of fire 
 to render palatable and nutritious animal and vegetable sub- 
 stances, and above all by his powers of social combination. 
 Instead of the form of his limbs being modified or acquiring 
 more agility and strength, instead of his sight or hearing 
 becoming more acute, his body would remain stationary while 
 his intellectual faculties would continually improve.* 
 
 Before, however, we embrace the views here set forth, we 
 must be sure that we are not underrating the vastness of the 
 time which it may possibly have taken for races so different 
 as the European and Negro to diverge from a common type. 
 Broca, in his work on Anthropology, when speaking of the 
 paintings preserved in Egyptian temples nearly 4,000 years 
 old, says that, besides Negroes and Greeks, there are repre- 
 sentations of Jews, Mongols, Hindoos, and natives of the 
 valley of the Nile, proving that all these types were then 
 as distinct as they are now. He nevertheless thinks that 
 climate, social condition, alimentation, and mode of life may 
 . have determined originally the diversity of races, although it 
 is evident that three or four thousand years is but a minute 
 fraction of the time required to bring about such wide diver- 
 gence from a common parent stock. 
 
 Mr. C. L. Brace, in his answer to Mr. Wallace, has re- 
 marked that when members of the Anglo-Saxon race have 
 in the course of the last two centuries colonised a distant 
 
 * Human Races, &c. Anthropological Review, May 1864, p. clriii. 
 
472 DISTINCT EACES OF MAN [Cn. XLIII. 
 
 country, they have, as in the United States of America, de- 
 viated in an appreciable degree from the original type, in 
 spite of the frequent intermarriage of the new-settlers with 
 emigrants coming from the mother country. ' The form,' 
 he says, ' has "become more angular and muscular, the com- 
 plexion darker, and the face longer and thinner. The intel- 
 lectual and moral powers of the Anglo-American have not 
 been deficient, and yet they have not preserved him from varia- 
 tion.' It is also very commonly asserted that in a few genera- 
 tions the English settlers in Australia have varied somewhat 
 after the manner of the Anglo-Americans. Grant that even 
 a slight change can be superinduced in two centuries, what 
 may not thousands of centuries have effected when the new 
 settlers were wandering into zones of latitude far more distinct 
 than those of England, North Africa, and South Australia ? 
 
 We may, however, concede to Mr. Wallace that when first 
 mankind emerged from its primitive dwelling-place and began 
 to people the unoccupied continents and islands, the forma- 
 tion of marked races may have proceeded at a somewhat 
 faster rate than now. After having been for a long time 
 as strictly confined to one district as are now the chim- 
 panzee or orang-utan, being still in a state of ignorance and 
 barbarism somewhat lower than that of the Australian savage 
 or the Andaman islander, man may have spread in scattered 
 hunter-tribes over new latitudes, often encountering very 
 imgenial climates in regions where food was abundant. Under 
 such circumstances the mortality of the population would be 
 great, and Natural Selection very active in giving a prefer- 
 ence to certain varieties over others. In Great Britain and 
 Belgium it has been shown by statistical returns that about 
 one tenth of the population die before they are a month old, 
 and one fourth in early childhood. If in the newly settled 
 territories the transitions from the extremes of heat and cold 
 were frequent, those individuals who had weak lungs would be 
 the victims, whereas in other regions where the temperature 
 was very equable throughout the year, these same persons 
 might be the most healthy and most likely to grow up and 
 become the progenitors of the race destined to people the 
 newly occupied district. So of other variations in some 
 
en. XLIIL] COINCIDENT WITH ZOOLOGICAL PROVINCES. -17:5 
 
 cases a darker skin, in others a lighter complexion, might be 
 most favourable, but many generations must pass away before 
 a combination of characters best suited to the surrounding 
 conditions would be attained. 
 
 Coincidence of the range of the more marked human races with 
 the great zoological provinces. Professor Agassiz has called 
 attention to the important fact, that each of the more marked 
 races of the human family, such as the white race, the Chinese, 
 the New Hollanders, the Malays, and the Negroes, is limited 
 to some great zoological province. This circumstance, he 
 remarks, shows most unequivocally the intimate relation 
 existing between mankind and the animal kingdom in their 
 adaptation to the physical world. The same naturalist, how- 
 ever, has scarcely laid sufficient stress on one marked excep- 
 tion to this rule, namely, that over the whole continent of 
 America south of the Arctic zone (or the region which is 
 inhabited by Esquimaux) all the numerous tribes of Red 
 Indians have the same physical character and are of one and 
 the same race.* Dr. Morton had already declared this to be 
 the case after studying the craniological characters of the 
 American Indians from Canada to Patagonia. Nevertheless 
 this continent comprises two of the great zoological regions 
 before defined (pp. 335 340) as the Neoarctic and Neotro- 
 pical. On independent grounds Mr. Henry W. Bates has 
 arrived at the conclusion that the Red Indian must have 
 immigrated in comparatively modern times into the hot 
 regions of equatorial America. Even the European, he 
 says, bears exposure to the sun or to unusually hot weather 
 quite as well as the Indians, while the Negro is far better 
 suited to the same climate, for he escapes many epidemic 
 diseases incidental to hot latitudes which cause great 
 havock among the Indians. The latter, according to Mr. 
 Bates, lives as a stranger in his own country, the valley of 
 the Amazons. His constitution was not originally fitted, and 
 has not since his immigration become perfectly adapted, to 
 the climate of tropical America, f 
 
 * Agassiz, Diversity of Origin of the f Bates, Naturalist on the Amazons, 
 
 Human Races. Christian Examiner, vol. ii. p. 200. 
 July 1850. 
 
474 OKIGIN AND DISTEIBUTION OF MAN. [Cir. XLIII. 
 
 We have as yet no geological data to enable us to determine 
 the relative antiquity of man in the Old and New World. 
 Some fossil remains of our species found in the valley of the 
 Mississippi imply, if their geological position has been cor- 
 rectly ascertained, that man was contemporary with many 
 extinct quadrupeds and inhabited that region before it under- 
 went some of its latest geographical changes.* But as a 
 matter of speculation, if we assume that mankind, like every 
 other species, has had but one birthplace, and if we also sup- 
 pose him to have been derived from some nearly allied proto- 
 type, we must incline to the belief that the peopling of America 
 took place at a later period than that of the Old World ; for 
 man, as has been truly said, is an ' Old- World type,' his bodily 
 structure, as before observed (p. 231), being closely related to 
 that of the quadrumana of Africa and Asia, and differing 
 widely from all the species of the Western Hemisphere. But 
 the first settling of mankind in America, though a compara- 
 tively modern event, may still date back as far as the Paleo- 
 lithic period of Western Europe. Some of the latest changes 
 in the valley of the Mississippi and its tributaries may have 
 taken place since the remains of man and of some extinct 
 animals were buried in superficial deposits, yet throughout the 
 period of these geographical changes the chain of the Andes 
 may have been always continuous from Canada to Patagonia, 
 and may have facilitated the spread of a single race from one 
 end of the continent to another. 
 
 Mr. Wallace in his memoir on Man in the Malay Archipe- 
 lago,f has explained how nearly the line a, b (map, fig. 132, 
 p. 347), which separates the regions of the Indian and the 
 Australian faunas, agrees with the geographical boundary 
 line c, b (ibid.) dividing the habitations of the Indo-Malayaii 
 and the Papuan races. He describes the typical Malayan 
 race, found almost exclusively in the western half of the archi- 
 pelago, as of a light reddish brown colour with a more or less 
 olive tint, hair black and straight, the face almost destitute 
 of beard, the stature below the average European, while the 
 Papuan race is much darker, sometimes almost as black as 
 the Negro, the hair growing in tufts and frizzly, the face 
 
 * Lyell, ' Antiquity of Man,' p. 200. f Read at Brit, Assoc., Newcastle, 1864. 
 
C'H. XLIII.l DISTINCTNESS OF EUROPEAN AND NEGRO. 475 
 
 adorned with a beard, the stature equal to that of the 
 European. The intellectual and moral characteristics of the 
 two races are also described as strongly contrasted. These 
 Papuans are found in New Guinea, while the Malays inhabit 
 Borneo, two large islands almost exactly agreeing in climate 
 and physical features, and within 300 miles of each other, and 
 yet in which there is as total a diversity of animal productions 
 as there is distinctness in the races of man. If we assume 
 that these two races came originally from a common stock, 
 we must suppose that they have been each of them separately 
 exposed for hundreds of generations to a distinctness of 
 external conditions analogous to that which, according to the 
 theory of Transmutation, has, in the course of a much longer 
 period, produced the discordance of species observed in the 
 Indian and Australian regions. 
 
 Distinctness of Negro and European^ and question of multiple 
 origin of man. It must be admitted, however, that we cannot 
 so easily account for the differentiation of the Papuan and 
 the Malay races as we can understand how the Negro ac- 
 quired characters so different from all other members of the 
 human family. For the natural barriers of the Ethiopian 
 province, with the ocean 011 three sides and the great 
 desert (submerged in Pliocene times) on the fourth, may well 
 be supposed to have cut off for an indefinite lapse of ages a 
 barbarous population from all intercourse with the rest of 
 mankind, and to have given to peculiar external conditions 
 an opportunity of fixing certain variations and forming a race 
 without parallel in other parts of the world. The divergence, 
 indeed, of the Negro from the European, not only in the colour 
 of his skin, the texture and mode of growth of his hair, his 
 features, the proportion of his limbs, and the average size of 
 the brain, has led some naturalists to maintain that he is 
 more than a mere variety of mankind, and ought to rank as 
 a separate species. 
 
 Professor Agassiz, without going so far, believes neverthe- 
 less that the parent stocks from which these and other 
 leading varieties have descended were originally distinct. 
 According to him, a great number of individuals of each of 
 the principal races of man were called into being when the 
 
476 ORIGIN AND DISTRIBUTION OF MAN. [Cn. XLIII. 
 
 race was created possessing all those characters which their 
 posterity afterwards inherited ; just as the same author im- 
 agines that a great many representatives of each species of 
 animal, especially species having social habits, were created 
 in large numbers, so as at once to people the whole region 
 which they were destined to inhabit. This theory has at 
 least the merit of being consistent with itself, and relieves the 
 opponents of Transmutation from the dilemma of explaining 
 why, if so great a divergence from a parent type as that of 
 the white man and negro can take place, a like modifiability 
 should not be able, in the course of ages, to go a step farther, 
 and give rise to differences of specific value. That the races 
 of mankind should never have diverged so far as to become 
 incapable of intermarrying and producing fertile offspring is 
 quite intelligible, if we consider the manner in which tribe 
 wars against tribe, and how the inhabitants of the temperate 
 and colder regions have continually invaded and overpowered 
 the more indolent and less progressive tenants of tropical 
 latitudes. These conquests explain the blending at the point 
 of contact of one race into another, which has led many 
 naturalists to affirm that instead of the five principal types 
 of Blumenbach, there are fifty, if not more than a hundred 
 races, each of which have had their own Adam and Eve. 
 
 Six-fingered variety of man as bearing on the mutability of 
 his organisation. As to the supposed want of flexibility in 
 the bodily structure of man ever since the Paleolithic period, 
 we ought to bear in mind that according to the theory of 
 Transmutation we can only expect those parts of his organ- 
 isation to vary, the improvement of which would be useful to 
 the individual or tribe giving them an advantage in the 
 struggle for life. We have seen (page 297), that the experi- 
 ments of the breeder and horticulturist prove that one part 
 of the organisation of an animal or plant may be greatly 
 altered by selection, while other parts which are neglected 
 remain unchanged or do not vary in a perceptible degree. 
 But the organ the variation of which would be most impor- 
 tant in the case of man is the brain, arid it is on cerebral 
 development that Natural Selection would operate most 
 effectively. Before considering whether, in the course of 
 
CH. XLIII.J SIX-FINGKRKI) VARIETY OF MAX. 477 
 
 thousands of generations, some favourable modifications may 
 not have taken place in this organ, giving- to one race an 
 advantage over others, it may be well to allude to a singular 
 deviation from the normal standard which has been observed 
 in man, and some other of the mammalia, and which has 
 deservedly attracted much attention. This deviation consists 
 in the occurrence of six, instead of five digits, of which ex- 
 amples are found in the dog and the cat as well as in human 
 beings. Mr. Darwin, after having tabulated the cases of 46 
 persons with extra digits on one or both hands or feet, which 
 he found recorded in various works or which had been 
 privately communicated to him, ascertained that in this 
 number, 73 hands and 75 feet were thus affected, proving, in 
 contradiction to previous opinions, that the hands are not 
 more frequently affected than the feet. Professor Huxley 
 cites in detail from Reaumur the case of a Maltese couple 
 named Kelleia, who, having hands and feet constructed on the 
 ordinary human model, had born to them a son, Gratio, who 
 possessed six perfectly movable fingers on each hand, and six 
 toes, not quite so well formed, on each foot. This son mar- 
 ried a woman with the ordinary pentadactyle extremities, and 
 of their children one had six fingers and six toes, and the 
 others were of the normal type. The six-fingered son had 
 three out of four of his children six-fingered. But what 
 is more remarkable, two of Gratio's children of the normal 
 type having married five-fingered wives or husbands, never- 
 theless reproduced in the next generation the six-fingered 
 variety. Thus, although in each case one parent and some- 
 times both were five-fingered, the six-fingered variety per- 
 sisted down to the grandchildren of Gratio. If, observes 
 Professor Huxley, some of these last had been matched with 
 their cousins having the same abnormal structure, we cannot 
 doubt that a six-fingered and six-toed race would have been 
 perpetuated. In these cases it usually happens that the 
 supernumerary digit is supported on a metacarpal bone, and 
 furnished with all proper muscles, nerves, and vessels, being 
 so perfect as to escape detection, unless the fingers are 
 actually counted. Additional digits, says Darwin, have been 
 observed in negroes as well as in the white races. 
 
478 OKIGIN AND DISTRIBUTION OF MAN. [Cu. XLIII. 
 
 The frequent re-growth of supernumerary digits after they 
 have been cut off is another extraordinary fact which must 
 not be lost sight of by those who are disposed to speculate on 
 the nature and cause of this phenomenon. In one instance, 
 that of a person now living, the additional finger, when the 
 infant was about six weeks old, was removed at the joint, and 
 as soon as the wound healed, the digit began to grow, on 
 which the operation in about three months was repeated, 
 when the finger was once more reproduced including a bone. 
 In another example cited by Dr. Carpenter of a thumb double 
 from the first joint, the lesser thumb being furnished with a 
 nail was removed, but it grew again and reproduced a nail.* 
 Mr. Darwin regards these supernumerary digits in man as 
 retaining to a certain extent an embryonic condition, and 
 resembling in this respect the normal digits and limbs of the 
 lower vertebrate classes which are so prone to reproduction. 
 Spallanzani cut off the tail and legs of the same salamander 
 six times successively, and Bonnet cut them off eight times, 
 and they were always renewed. The pectoral and tail-fins 
 of many freshwater fish having been cut off have been per- 
 fectly restored in about six weeks' time. Fishes have some- 
 times in their pectoral fins more than five, sometimes as 
 many as twenty, metacarpal and phalangeal bones forming 
 so many rays, and occasionally bearing bony filaments, which 
 together clearly represent our digits with their nails. So 
 again in certain extinct reptiles, the Ichthyopterygia, ' the 
 digits may be seven, eight, or nine in number, a significant 
 mark,' says Professor Owen c of piscine affinity. 'f Mr. Dar- 
 win therefore suggests that the excess in number and the 
 power of re-growth of the supernumerary digits in man may 
 be an instance of reversion to an enormously remote and 
 multidigitate progenitor of very inferior grade. J As the 
 number five is so strictly adhered to in the digits of all the 
 higher vertebrata, and is at least never exceeded as a rule in 
 any living reptile, bird, or mammal, the excess above alluded 
 to is generally regarded as a monstrosity, the more so because, 
 although six is the more common variety, yet there are some- 
 
 * Darwin, Origin of Species, chap. xii. j See above, p. 291, on Darwin's 
 
 f- Ibid. theory of Pangenesis. 
 
l'ii. XLIIL] BARBARISM OF PRIMEVAL MAX. 479 
 
 times from seven to more than ten fingers or toes, more or 
 less perfect, on the same hand or foot, and occasionally less 
 than five. Certainly this deviation from the ordinary stan- 
 dard, as well as the re-growth of the amputated limb, does 
 not point in the direction of progressive improvement. If 
 it be looked upon as a malformation occasionally shared by 
 other mammalia, it only adds one more to innumerable other 
 bonds of connection by which the inferior animals and man 
 are united, whether in the perfection, or the occasional im- 
 perfection, of their organisation. 
 
 Whether man has been degraded from a higher or has risen 
 from a lower stage of civilisation. All our recent investiga- 
 tions in Europe into the state of the arts in the earlier stone 
 age, lead clearly to the opinion that at a period many 
 thousands of years anterior to the historical, man was in a 
 state of great barbarism and ignorance, exceeding that of 
 the most savage tribes of modern times. They were evidently 
 ignorant of metals, and of the arts of polishing stone im- 
 plements and of making pottery. Sir John Lubbock, in 
 discussing the question whether our ancestors have been 
 degraded from an original stock which was more highly 
 advanced in knowledge and civilisation, or has risen from a 
 lower state, observes that no fragment of pottery has been 
 found among the natives of Australia, New Zealand, and 
 the Polynesian islands, any more than ancient architectural 
 remains, in all which respects these rude tribes now living 
 resemble the men of the Paleolithic age. When pottery, he 
 says, is known at all, it is always abundant, and "though easy 
 to break, it is difficult to destroy. It is improbable that so 
 useful an art should ever have been lost by any race of man. 
 The theory, therefore, that the savage races have been de- 
 graded from a previous state of civilisation may be rejected. 
 ' Civilised nations long retain traces of their ancient bar- 
 barism, whereas barbarous ones retain no relics of a previous 
 more advanced state. The stone knives used by the Egyptian 
 and Jewish priests in religious ceremonies, after metal was 
 in use for secular purposes, point to an antecedent period 
 when such stone implements were in general use. They 
 
480 OIUGIN AND DISTRIBUTION OF MAN. [Cii. XLIII. 
 
 would long be regarded as sacred, and there would be a 
 reluctance to use a new substance in religious ceremonies.' * 
 Some have wished to found an argument in favour of the 
 superior mental endowments of the earliest races of mankind, 
 by pointing out that the Sanscrit, and some other of the 
 most ancient languages of Asia, are very artificial in their 
 grammatical construction and rich in abstract terms. But 
 the nations speaking these tongues will be regarded by every 
 geologist as modern when compared to the men of the Paleo- 
 lithic age. In tracing back the course of human events we 
 should first find a period when scattered migratory hordes 
 in the hunter state were spreading over Asia, and then a still 
 anterior period when one small area of land (possibly now in 
 great part submerged in the Indian or Pacific oceans) con- 
 tained the primitive stock from which they all have ramified, 
 and we may be sure, if the theory of Transmutation be true, 
 that such progenitors of mankind had a scantier vocabulary 
 than the humblest savage known to us. They would have 
 been unable to count as far as the fingers on one hand, and 
 would not have invented a single term expressive of an 
 abstract idea. When the first emigrants were spreading 
 over a wide continent, they would separate into small com- 
 munities, each of which would gradually acquire a language 
 of its own, but as often as one tribe became more powerful 
 than its neighbours, it would conquer them and absorb into 
 itself those who were not exterminated, imposing its lan- 
 guage on the conquered, yet sometimes borrowing from them 
 some terms and expressions. It is found that the number oJ 
 independent languages spoken in a continuous tract of land 
 is great in proportion to the barbarism of the natives, 
 Dominant tribes, as they multiply and advance in civilisation 
 and power, spread a single language over a vast area. The 
 Chinese for example, several thousand years before our time, 
 constituting as they still do a third of the population of the 
 globe, imposed on nearly the whole of their empire one lan- 
 guage, though diverging, it is true, into many dialects. Ho^ 
 long a time it required for one race thus to obtain supremacy 
 
 * On the Early Condition of Man, Sir JohnLubbock. British Assoc. 1867. 
 
CH. XLIIL] BLENDING OF RACK.-. 481 
 
 over a large part of Asia, we know not, but we may look 
 forward to the time when the Europeans, especially the 
 Anglo- Saxon race, will in like manner spread over still larger 
 areas, displacing the aboriginal tribes of America, and, like 
 their predecessors the Red Indians, spreading from the Arctic 
 Region to Patagonia, so that one race and perhaps one 
 language may eventually prevail throughout the Neoarctic 
 and Neotropical provinces before alluded to. 
 
 It may seem to us almost incredible now that the progress 
 of the arts has given us such powers of locomotion, such 
 facilities of traversing continents and circumnavigating the 
 globe, to say nothing of exchanging ideas instantaneously 
 with the inhabitants of the remotest regions, that nations, 
 even after they had advanced far in civilisation, could remain 
 so isolated as we know them to have done. How the Greeks, 
 for example, in spite of their extraordinary genius and 
 their spirit of commercial enterprise, could have continued 
 so ignorant of the geography of countries only a few hun- 
 dred miles distant from the coasts of the Mediterranean 
 and Black Seas. The superior power which science confers 
 is always increasing in a geometrical ratio, so that the dis- 
 placement of the weaker by the more civilised nations is 
 accelerated to an extent without parallel in the history of 
 the past. Hence in future there will be a greater blending 
 of races, and a constant tendency towards the establishment 
 of one race and one language throughout the globe. It 
 seems probable that the divergence from a common stock 
 reached its climax, physically and psychologically, in the 
 formation of the Caucasian and Negro races. If, therefore, 
 we consider this differentiation as amounting only to one of 
 race, it seems to follow that two rational species descending 
 from a common parentage cannot coexist on the globe. In 
 embracing this conclusion, however, we are not precluded from 
 entertaining the opinion that the descendants of the same 
 rational progenitors, if compared at two very distant times., 
 may not differ as much as might entitle them to rank as 
 distinct species. 
 
 M. Gaudry on intermediate forms between the Upper Miocene 
 and living mammalia. The relationship of man to a supposed 
 
 VOL. II. I I 
 
482 ORIGIN AND DISTRIBUTION OF MAN. [Cn. XLIII. 
 
 antecedent species nearly allied in bodily structure, offers at 
 present to the geologist a field of somewhat unprofitable 
 speculation, so long as the Pliocene and Post-Pliocene for- 
 mations of tropical Africa and India are still unexplored. 
 We are only beginning, by aid of paleontology, to trace back 
 the passage through a series of gradational forms from 
 the living mammalia to those of the Pliocene and still 
 older Miocene period. But in this department of osteology, 
 the evidence already obtained since the time of Cuvier, in 
 favour of transmutation, is certainly very striking. By no 
 naturalist has its bearing been more clearly pointed out than 
 by M. Gaudry, who, under the influence of the great teachers 
 who preceded him, entered on the enquiry with a theoretical 
 bias directly opposed to the conclusions which he now so 
 ably advocates. In his luminous memoir on the fossil bones 
 found at Pikermi, near Mount Pentelicus, fourteen miles 
 east of Athens, he has pointed out the transition through 
 many intermediate forms of Upper Miocene species to others 
 of Pliocene and Post-Pliocene date, showing how each suc- 
 cessive discovery has enabled us to bridge over many gaps 
 which existed only twenty or thirty years ago. Having 
 myself had the advantage of seeing the original specimens 
 collected by this zealous geologist and now in the museum 
 of Paris, and having had the connecting links supplied by 
 species obtained from other parts of the world laid before me, 
 I have been able the more fully to appreciate the force of 
 the evidence appealed to in favour of Transmutation. But 
 all who study M. Gaudry 's memoir may form an independent 
 opinion for themselves, by a glance at the genealogical tables 
 of certain family types, in which the gradation of Miocene] 
 through Pliocene and Post-Pliocene to living genera and! 
 species is traced. 
 
 In the list of proboscidians, for example, -we behold chro- 
 nologically arranged more than thirty distinct species, be- 
 ginning with the mastodons of the Middle Miocene Period 
 found in France, and continued through those of the Upper 
 Miocene of Ava, the Sewalik Hills, Pikermi, and Eppelsheim, 
 to the Pliocene forms of Southern India, Italy, and England, 
 where both the mastodons and elephants occur. Finally we 
 
('. XLlll.j THEORY OF TRANSMUTATION. 483 
 
 are conducted to the Post- Pliocene or quaternary species of 
 Europe and America, till we end with, the two existing 
 elephants of India and Africa. Again of the rhinoceros 
 family, besides the five living species, fifteen extinct ones are 
 enumerated, and in addition to these, some generic forms of 
 older or Eocene date, belonging to the same great family. 
 The fossil pedigree of the horse tribe is equally instructive, 
 traced from the Middle and Upper Miocene Hipparion of 
 France, Germany, Greece and India, through the Pliocene 
 and Post- Pliocene equine species of Europe, India, and 
 America, to the living horse and ass. But the twelve equine 
 species referred by Leidy to seven genera detected in the 
 valley of the Mobrara in Pliocene and Post-tertiary for- 
 mations,*" are omitted from this table as not having been 
 yet described in sufficient detail, and they would certainly, if 
 inserted in M. Gaudry's table, help to fill up many a hiatus 
 between the forms which he has recognised. The pig family, 
 as well as some carnivora, such as the hysena, have also 
 furnished ample materials in illustration of the same law of 
 a gradual change of structure. 
 
 Even the quadrumana are beginning to afford proofs of 
 the manner in which the existing apes have ramified from 
 their extinct prototypes, although our information respecting 
 them, whether from Pikermi or elsewhere, has been hitherto 
 almost exclusively derived from extra-tropical latitudes, 
 where there are now no living representatives of the order. 
 Only fourteen species of the ape and monkey tribe have as 
 yet been detected in a fossil state, and each of these has 
 usually furnished but a few bones of its skeleton to the 
 osteologist. . Yet they have not failed to throw much light 
 on the transmutation hypothesis. The Dryopithecus of the 
 Miocene era of the south of France, though specifically 
 distinct from any ape now existing, comes so near to the 
 living Gibbon, or long-armed ape, as not to deserve, in Pro- 
 fessor Owen's opinion, the separate generic rank assigned to 
 it by Lartet. All the other fossils of Europe and Asia have 
 an affinity to living species or genera of the Catarrhine 
 
 * See above, p. 337. 
 i i 2 
 
484 ORIGIN AND DISTRIBUTION OF MAN. [Cn. XLIIL 
 
 division, and those of America, found in Brazilian caves, to 
 the Platyrrhiiie. 
 
 As to the Mesopithecus of Pikermi, the skeleton is almost 
 complete, more so than that of any other fossil ape yet brought 
 to light. It differs generically from any of the living Indian 
 forms, not so much by presenting any novel features in its 
 structure as by combining characters which now belong to 
 two distinct Indian types. For, says M. Gaudry, one might 
 say that the living Semnopitheci of India have borrowed 
 their skulls from this Miocene type, while the living Macaci 
 have borrowed from it their limbs. c ln how different a 
 light,' exclaims this eminent paleontologist, 6 does the question 
 of the nature of species now present itself to us from that 
 in which it appeared only twenty years ago, before we had 
 studied the fossil remains of Greece and the allied forms of 
 other countries ; how clearly do these fossil relics point to the 
 idea that species, genera, families, and orders now so distinct, 
 have had common ancestors ! ' ' The more we advance and fill 
 up the gaps, the more we feel persuaded that the remaining 
 voids exist rather in our knowledge than in nature. A few 
 blows of the pickaxe at the foot of the Pyrenees, of the 
 Himalaya, of Mount Pentelicus in Greece, a few diggings in 
 the sandpits of Eppelsheim, or in the Mauvaises Terres of 
 Nebraska, have revealed to us the closest connecting links 
 between forms which seemed before so widely separated ! 
 How much closer will these links be drawn when paleon- 
 tology shall have escaped from its cradle ! ' * 
 
 Many of the most cultivated literary critics, and some 
 eminent mathematicians, have shown, in the discussions which 
 have arisen on the origin of species, an entire incapability 
 of weighing and appreciating the evidence for and against 
 Transmutation, and this chiefly for two reasons : first, they 
 have never been called upon, as classifiers in natural history, 
 practically to decide whether certain forms, fossil or recent, 
 should rank as species or as mere varieties a point on which 
 the most eminent zoologists and botanists often disagree ; 
 secondly, they are quite unconscious of the fragmentary 
 
 * Gaudry, Animaux Fossiles de Pikermi, 186G, p. 34. 
 
Cii. XhIII.1 CEIM-:i',J!AL CONTOHMATIOX. 485 
 
 nature of the record with which the geologist has to deal.* 
 To one who is not aware of the extreme imperfection of this 
 record, the discovery of one or two missing links is a fact of 
 small significance ; but to those who are thoroughly imbued 
 with a deep sense of the defectiveness of the archives, each 
 new form rescued from oblivion is an earnest of the former 
 existence of hundreds of species, the greater part of which are 
 irrecoverably lost. 
 
 Progressive development in the cerebral conformation of the 
 vertebrata, including man. I have already remarked when 
 combating the notion that man in his corporeal structure has 
 arrived at a fixed and stationary condition, that we have 
 no right to make such an assumption, until we have acquired 
 a more definite idea of the number of centuries which it 
 took for the most marked of the human races to diverge, in 
 different directions, so far from a common type. The rate of 
 change generally in the animal and vegetable kingdoms is 
 slow and insensible, and naturalists have never yet witnessed 
 the formation of any one of the wild races which they regard 
 as mere geographical varieties. They know not how many 
 thousand generations it may have required to produce such 
 changes ; but we cannot infer in their case, or in that of man, 
 that the era of the immutability of species has arrived. If 
 the organisation of man has been modified in comparatively 
 modern times, it is probably, as before hinted, in his cerebral 
 development that variation has been manifested. 
 
 Linnaeus declared that he could not distinguish man 
 generically from the ape, and Professor Owen has spoken of 
 the ' all-pervading similitude of structure every tooth, every 
 bone, being strictly homologous ' yet the same great anato- 
 mist considers man's superior cerebral development as en- 
 titling him to be placed in a sub-class apart from all the 
 other mammalia. He has proposed a new classification of 
 the highest division of the vertebra ta with reference to the 
 characters of their brain, and its greater or less resemblance, 
 in volume and structure, to that of man. Some have ob- 
 jected, not perhaps without reason, that every such attempt 
 
 * See above, Vol. I. p. 318. 
 
486 ORIGIN AND DISTRIBUTION OF MAN. [Cn. XLIII. 
 
 to classify the animate creation by reference to a single 
 organ, or one set of characters, has failed, and that in order 
 to obtain a natural system of arrangement, we must duly 
 consider the combined claims of as large a part as possible of 
 the whole organisation. Nevertheless the extent to which 
 cerebral conformation, taken by itself, has enabled Professor 
 Owen to place the genera and orders of mammalia in an 
 ascending scale, shows how predominant is the importance of 
 the brain, and the intimate connection of this mysterious 
 organ with mental power. We see the monotremes (the 
 Echidna and duck-mole) take the lowest place in the scale, 
 followed by the marsupials, all having brains the most 
 dissimilar in capacity and form from that of man ; while the 
 quadrumana take the highest place measured by the same 
 standard, the family to which the chimpanzee and gorilla 
 belong being at the head of the long list of tabulated genera 
 and orders. It will also be observed that the bats, instead 
 of maintaining the leading position among the ' Primates ' 
 which they occupied in the Linnsean classification, are as- 
 signed to a different and inferior sub-class, far more in 
 accordance with their relative intelligence. 
 
 If we go still farther and compare the mammalia with the 
 fish, or the lowest class of the vertebrata, we find a con- 
 tinuance of the same descending scale in accordance with a 
 diminution in the volume of brain, as well as in a lessened 
 concentration of the nervous system in -one part of the 
 animal ; for the farther we recede from the human type, the 
 smaller is the proportionate quantity and weight of the 
 brain as compared to the spinal marrow. It is true that in 
 attempting to apply these rules in detail the anatomist is 
 often at fault, because he finds that in any given group of 
 animals the larger species have proportionately smaller 
 brains, or, in other words, the mass of the brain does not 
 increase in the same ratio as the general bulk of the animal. 
 Still the general proposition before laid down holds good, 
 that the degree of intelligence and mental power enjoyed by 
 the inferior animals increases with the increase of their 
 cerebral capacity, and with the resemblance in the structure 
 of their brain to that of man- 
 
Cu. XLIIL] PROGRESSIVE DEVELOPMENT. 487 
 
 If we take the Hottentot as the least advanced variety of 
 the negro type, we find not only the volume of the brain to 
 be far below that of the average of the European, but that 
 the two hemispheres are more symmetrical, and that in this 
 and every peculiarity in which it deviates from the Caucasian 
 standard, it approaches nearer in character to the Simian 
 brain. The theory therefore of Progressive Development 
 and Transmutation would lead us to anticipate that the 
 human skull of the Paleolithic Period would prove to be 
 more pithecoid than the cranium of any living race. Our 
 data are as yet too scanty to allow of our drawing safe con- 
 clusions from the fossil remains of the era in question, for 
 the Neanderthal skull may be an exceptional variety, as may 
 some other remains of a somewhat ape-like character, lately 
 brought to light by M. Dupont from a deposit containing 
 the relics of extinct mammalia in the Belgian caves. It 
 may also be said that there is no reason why the Paleolithic 
 cranium should be much if at all inferior to that of an 
 Australian, for the state of the arts in the Paleolithic Period 
 accords well with that phase of advancement which the 
 Australian and some other savage tribes had reached when 
 they first became known to Europeans. 
 
 In the ninth chapter of the first volume, a brief summary 
 was given of the evidence in favour of the successive ap- 
 pearance in chronological order of fish, reptile, bird and 
 mammal, and lastly among the mammalia, the coming in of 
 those anthropomorphous species which most resemble man 
 in. structure. If we then regard the advent of man as the 
 last and culminating point attained in this continuous series 
 of developments, we may well imagine that, during the tran- 
 sition from the quadrunianous to the human organisation, 
 the brain was that part which underwent the chief modifica- 
 tion. And when its growth and improvement had once 
 conferred on man a decided superiority over the brutes, it 
 would continue to be the organ which would go 011 im- 
 proving, so as to give one race an advantage over others in 
 the struggle for life. 
 
 Even if the paleontologist had obtained fossil crania of 
 an age immediately antecedent to the Paleolithic, it might 
 
488 ORIGIN AND DISTRIBUTION OF MAX. [On. XLIII. 
 
 be difficult for him to derive from them a knowledge of the 
 successive steps made in an ascensive scale, if, as some 
 physiologists suspect, the quality of the brain has often 
 more to do than its quantity with intellectual superiority. 
 But although size alone may be no safe criterion of relative 
 mental power, it is undeniable that the skulls of a hundred 
 individuals of transcendent ability would exceed in their 
 average dimensions the skulls of an equal number of persons 
 of inferior mental power. Whether the brain, like any 
 other organ, gains strength by exercise, and whether an 
 improvement thus acquired in the intellectual faculties may 
 be handed down to the offspring by inheritance, are still 
 matters of controversy. But no one is disposed to dispute 
 that if some modification of an organ, or instinct, be pro- 
 duced by what is called ' spontaneous variation,' there is a 
 decided propensity in the new structure or attribute to 
 perpetuate itself by inheritance, as in the case of the six- 
 fingered variety of man, before mentioned (p. 476), or the 
 stunted legs of the Ancon sheep (p. 312). 
 
 If, therefore, it be part of the plan of nature that living 
 beings should occasionally give birth to varieties in some 
 slight degree more perfect in the specialisation of their parts 
 and organs, or in the perfection of an organ, instinct., or 
 mental faculty, than had been enjoyed by any of their prede- 
 cessors, Natural Selection will ensure the eventual success of 
 such individuals in the struggle for life. When Mr. Darwin 
 says that he does not believe in a law of necessary develop- 
 ment, he means that simple and unimproved structures may 
 sometimes be best fitted for simple conditions of life, and that 
 even a degradation instead of an advance in structure may 
 occasionally be advantageous. Nevertheless, in the long run, 
 there will be a tendency, in the higher and more perfect 
 organisms, to survive and multiply, not at the expense of the 
 lower, with most of whom they will never come into competi- 
 tion, but at the expense of those which are most nearly allied to 
 them. The repeated failure of particular varieties having 
 organs and attributes somewhat superior to any of their pro- 
 genitors, by no means implies that the final predominance of 
 such organisms is left to chance. It suffices that there should 
 
CH. XLIIL] LAW OF 1R()(J KKSS. -l.S'.l 
 
 be a power in nature, capable of giving rise to individuals in 
 advance of all which have preceded them, and it then becomes 
 simply a question of time how soon the more improved 
 varieties will prevail. Their final success is certain, though 
 many adverse circumstances may retard the rate of progress. 
 
 Suppose a human infant endowed with intellectual capacity 
 superior to that of any one previously born into the world ; it 
 is as liable to be cut off in childhood as one less gifted, but 
 it has also an equal chance of growing up, and if it attains 
 maturity it will promote the advancement of the tribe to which 
 it belongs, inventing perhaps some warlike weapon or better 
 laws and institutions, and there will be a great probability 
 of some of the children of such an individual inheriting an 
 amount of talent above the average of their generation. The 
 more civilisation advances the less will mere bodily strength 
 and acuteness of the senses confer social superiority. But 
 still, as Darwin says, there is no fixed and necessary iaw of 
 progress. The institutions of a country may be so framed 
 that individuals possessing moderate or even inferior abilities 
 may have the best chance of surviving. Thus the Holy In- 
 quisition in Spain may for centuries carefully select from the 
 thinking part of the population all men of genius, all who dare 
 to question received errors and who have the moral courage 
 to express their doubts, and may doom them by thousands 
 to destruction, so as effectually to lower the general standard 
 of intelligence. But such exceptional institutions will not 
 arrest the onward march of the human race. It will only 
 depress one nation, causing it to decline in knowledge, power, 
 wealth, population, and political influence, and prepare for 
 the day when it will be conquered by some other people in 
 which freer scope has been given to intellectual progress. 
 
 Objections to Darwin's theory of Natural Selection. The 
 Duke of Argyll, in his lately published work on the 6 Reign of 
 Law,' has made some valuable criticisms on Mr. Darwin's 
 theory of Natural Selection, to which, in conclusion, I shall 
 now allude. After observing that we know nothing of the 
 natural forces by which new forms of life are called into being, 
 he says that if there were evidence that the new could be de- 
 veloped from the old, he cannot see why there should be any 
 
490 OKIGIN AND DISTKIBUTION OF MAN. [On. XLIII. 
 
 reluctance to admit the fact.* But he denies that sufficient 
 evidence in support of such a theory has yet been adduced. 
 The introduction, he admits, of new species c to take the place 
 of those which have passed away, is a work which has been 
 not only so often but so continuously repeated that it does 
 suggest the idea of having been brought about through the 
 instrumentality of some natural process. 'f This process, or 
 6 the adaptation of forces which can compass the required 
 modifications in animal structure in exact proportion to the 
 need of them, is in the nature of creation.' But Mr. Darwin, 
 he says, does not pretend to explain how new forms first ap- 
 pear, but only how when they have appeared they acquire a 
 preference over others. Mr. Darwin frankly confesses that 
 our ignorance of the laws of variation is profound : yet, says 
 the Duke, he seems sometimes to forget this and to speak of 
 Natural Selection as if it could account for the origin of 
 specie*, whereas, according to his own definition, it ' can do 
 nothing except with the materials presented to its hands. 
 It cannot select except among things open to selection. It 
 can originate nothing; it can only pick out and choose 
 among the things which are originated by some other law.'J 
 To speak therefore of Natural Selection as c producing ' 
 certain modifications of structure or new organs, and as 
 6 adapting ' them, is to ascribe to it results which it caii- 
 iiot bring about, and c the cause of which we cannot even 
 guess at.' 
 
 To me it appears that these criticisms are fkirly applicable 
 to those passages in Mr. Darwin's ' Origin of Species,' in 
 which Natural Selection is spoken of as capable of bringing 
 about any amount of change in the organs of an animal 
 provided a series of minute transitional steps can be pointed 
 out by which the transmutation may have been effected. 
 Thus, for example, if some one of the invertebrate animals 
 has a membrane or tissue without a single nerve, yet sensi- 
 tive to light, while another creature such as an eagle is 
 furnished with a perfect eye in which there is an apparatus 
 for concentrating the luminous rays, and for refracting 
 
 * Keign of Law, p. 227. I &eign of Law, p. 230. 
 
 f Ibid. p. 228. Ibid. p. 254. 
 
CH. XLIIL] THEORY OF NATURAL SELECTION. 491 
 
 pictures of external objects with, optic nerves to convey 
 these images to the brain, it is suggested that we may 
 understand how this perfect organ may have been ' formed 
 by Natural Selection ' if we can only find in nature a series 
 of animals which have organs of vision exhibiting all the 
 intermediate grades of structure between the two extreme 
 forms above mentioned. But in reality it cannot be said 
 that we obtain any insight into the nature of the forces 
 by which a higher grade of organisation or instinct is evolved 
 out of a lower one by becoming acquainted with the gra- 
 dational forms or states which have been passed through 
 during the transmutation. Even if we could discover geo- 
 logical evidence that every modification between a mere 
 power of sensation like that of a sponge and the intelligence 
 of an elephant had been represented by every intermediate 
 degree of instinct and capacity, and that beings endowed 
 with faculties more and more perfect had succeeded each 
 other in chronological order according to their relative 
 perfection, like the successive stages in the development 
 of the embryo from a simple germ-cell to the infant 
 mammifer, still the mystery of creation would be as great, 
 and as much beyond the domain of science, as ever. It is 
 when there is a change from an inferior being to one of 
 superior grade, from a humbler organism to one endowed 
 with new and more exalted attributes, that we are made 
 to feel that no modification of a progenitor, no principle 
 of inheritance, can explain the phenomenon. The ancestor 
 could not bequeath to its posterity that which it did not 
 possess itself, still less could the causes determining the 
 ' survival of the fittest ' give origin to individuals more 
 fit to occupy a conspicuous place in the system of nature 
 than any which had preceded them. 
 
 The author, however, of the 'Keign of Law' has by no 
 means argued, like the majority of Mr. Darwin's opponents, 
 as if nothing had been gained by the theory of Natural 
 Selection, merely because this principle may have had func- 
 tions assigned to it far higher than it can possibly discharge. 
 The real question at issue that on which the c Origin of 
 Species ' has thrown so much light is the same as that 
 
492 ORIGIN AND DISTRIBUTION OF MAX. [Cn. XLIII. 
 
 discussed by us in the last ten chapters. It is not whether we 
 can explain the creation of species, but whether species have 
 been introduced into the world one after the other, in the form 
 of new varieties of antecedent organisms and in the way of 
 ordinary generation, or have been called into being by some 
 other agency, such as the direct intervention of the First 
 Cause. Was Lamarck right, assuming progressive develop- 
 ment to be true, in supposing that the changes of the organic 
 world may have been effected by the gradual and insensible 
 modification of older pre-existing forms ? Mr. Darwin, with- 
 out absolutely proving this, has made it appear in the highest 
 degree probable, by an appeal to many distinct and indepen- 
 dent classes of phenomena in natural history and geology, 
 but principally by showing the manner in which a multitude 
 of new and competing varieties are always made to survive 
 in the struggle for life. The tenor of his reasoning is 
 not to be gainsaid by affirming that the causes or processes, 
 which bring about the improvement or differentiation of 
 organs, and the general advance of the organic world from 
 the simpler to the more complex, remain as inscrutable to us 
 as ever. 
 
 When first the doctrine of the origin of species by trans- 
 mutation was proposed, it was objected that such a theory 
 substituted a material self-adjusting machinery for a Supreme 
 Creative Intelligence. But the more the idea of a slow and 
 insensible change from lower to higher organisms, brought 
 about in the course of millions of generations according to 
 a preconceived plan, has become familiar to men's minds, the 
 more conscious they have become that the amount of power, 
 wisdom, design, or forethought, required for such a gradual 
 evolution of life, is as great as that which is implied by a 
 multitude of separate, special, and miraculous acts of crea- 
 tion. 
 
 A more serious cause of disquiet and alarm arises out of 
 the supposed bearing of this same doctrine on the origin of 
 man and his place in nature. It is clearly seen that there 
 is such a close affinity, such an identity in all essential points, 
 in our corporeal structure and in many of our instincts 
 and passions, with those of the lower animals that man is so 
 
Cn. XLLLL] PALI-:OLiTlIlC MAX. -1'Jo 
 
 completely subjected to the same general laws of reproduc- 
 tion, increase, growth, disease, and death, that if progres- 
 sive development, spontaneous variation, and natural selection 
 have for millions of years directed the changes of the rest of 
 the organic world, we cannot expect to find that the human 
 race has been exempted from the same continuous process of 
 evolution. Such a near bond of connection between man 
 and the rest of the animate creation is regarded by many as 
 derogatory to our dignity. It certainly gives a rude shock to 
 many traditional beliefs, and dispels some poetic illusions re- 
 specting an ideal genealogy which scarcely 'appeared less than 
 archangel ruined.' But we have already had to exchange 
 the pleasing conceptions indulged in by poets and theologians 
 as to the high position in the scale of being held by our 
 early progenitors, for more humble and lowly beginnings, 
 the joint labours of the geologist and archeologist having 
 left us in no doubt of the ignorance and barbarism of Paleo- 
 lithic Man.*" 
 
 We are sometimes tempted to ask whether the time will 
 ever arrive, when science shall have obtained such an ascen- 
 dancy in the education of the millions, that it will be possible 
 to welcome new truths, instead of always looking upon them 
 with fear and disquiet, and to hail every important victory 
 gained over error, instead of resisting the new discovery, long* 
 after the evidence in its favour is conclusive. The motion of 
 our planet round the sun, the shape of the earth, the existence 
 of the antipodes, the vast antiquity of our globe, the distinct 
 assemblages of species of animals and plants by which it 
 was successively inhabited, and lastly the antiquity and bar- 
 barism of Primeval Man, all these generalisations, when first 
 announced, have been a source of anxiety and unhappiness. 
 The future now opening before us begins already to reveal 
 new doctrines, if possible more than ever out of harmony 
 with cherished associations of thought. It is therefore de- 
 sirable, when we contrast ourselves with the rude and super- 
 stitious savages who preceded us, to remember, as cultivators 
 of science, that the high comparative place which we have 
 
 * For remarks on Paleolithic Man see close of Chapter XLVIL 
 
494 ORIGIN AND DISTRIBUTION OP MAN. [Cn. XLIII. 
 
 reached in the scale of being has been gained step by step 
 by a conscientions stndy of natural phenomena, and by 
 fearlessly teaching the doctrines to which they point. It is 
 by faithfully weighing evidence, without regard to precon- 
 ceived notions, by earnestly and patiently searching for what 
 is true, not what we wish to be true, that we have attained 
 that dignity, which we may in vain hope to claim through the 
 rank of an ideal parentage. 
 
195 
 
 CHAPTER XLIY. 
 
 ENCLOSING OF FOSSILS IN PEAT, BLOWN SAND, AND VOLCANIC 
 
 EJECTIONS. 
 
 
 
 DIVISION OF THE SUBJECT IMBEDDING OF ORGANIC REMAINS IN DEPOSITS ON 
 
 EMERGED LAND GROWTH OF PEAT SITE OF ANCIENT FORESTS IN EUROPE 
 
 NOW OCCUPIED BY PEAT BOG IRON-ORE PRESERVATION OF ANIMAL SUB- 
 STANCES IN PEAT MIRING OF QUADRUPEDS BURSTING OF THE SOL WAY 
 MOSS IMBEDDING OF ORGANIC BODIES AND HUMAN REMAINS IN BLOWN 
 
 SAND GREAT DISMAL SWAMP MOVING SAXDS OF AFRICAN DESERTS BURIED 
 
 TEMPLE OF IPSAMBUL IN EGYPT DRIED CARCASSES IN THE SANDS OF THE 
 DESERT SAND-DUNES AND TOWNS OVERWHELMED BY SAND-FLOODS IMBED- 
 DING OF ORGANIC AND OTHER REMAINS IX VOLCANIC FORMATIONS ON THE 
 LAND. 
 
 THE second branch of our enquiry, respecting changes of 
 the organic world, relates to the processes by which the 
 remains of animals and plants become fossil, or are buried in 
 the earth by natural causes,. M. Constant Prevost divided 
 the effects of geological causes into two great classes : those 
 produced during the submersion of land beneath the waters, 
 and those which take place after its emersion. Agreeably to 
 this classification, I shall consider, first, in what manner 
 animal and vegetable remains become included and preserved 
 in deposits on emerged land, or that part of the surface 
 which is not permanently covered by water, whether of lakes 
 or seas; secondly, the manner in which organic remains 
 become imbedded in deposits of lakes and seas. 
 
 Under the first division, I shall treat of the following 
 topics : 1st, the growth of peat, and the preservation of 
 vegetable and animal remains therein ; 2ndly, the burying of 
 organic remains in blown sand ; 3rdly, of the same in the 
 ejections and alluviums of volcanos ; 4thly, in alluviums 
 generally, and in the ruins of landslips; 5thly, in the mud 
 and stalagmite of caves and fissures. 
 
496 ENCLOSING 01 FOSSILS IN PEAT, [On. XLIV. 
 
 Growth of peat, and preservation of vegetable and animal 
 remains therein. The generation of peat, when not com- 
 pletely under water, is confined to moist situations, where 
 the temperature is low. It may consist of any of the nu- 
 merous plants which are capable of growing in such stations 
 but a species of moss (Sphagnum) constitutes a considerable 
 part of the peat found in marshes of the north of Europe ; 
 this plant having the property of throwing up new shoots in 
 its upper part, while its lower extremities are decaying;* 
 Reeds, rushes, and other aquatic plants may usually be traced 
 in peat ; and their organisation is often so Qntire that there 
 is no difficulty in discriminating the distinct species. 
 
 Analysis of peat. In general, says Sir H. Davy, one 
 hundred parts of dry peat contain from sixty to ninety-nine 
 parts of matter destructible by fire ; and the residuum consists 
 of earths usually of the same kind as the substratum of 
 clay, marl, gravel, or rock, on which they are found, together 
 with oxide of iron. c The peat of the chalk counties of 
 England,' observes the same writer, c contains much gypsum: 
 but I have found very little in any specimens from Ireland 
 or Scotland, and in general these peats contain very little 
 saline matter.' f From the researches of Dr. MacCulloch, it 
 appears that peat is intermediate between simple vegetable 
 matter and lignite. J 
 
 Peat abundant in cold and humid climates. Peat is some- 
 times formed on a declivity in mountainous regions, where 
 there is much moisture ; but in such situations it rarely, if 
 ever, exceeds four feet in thickness. In bogs, and in low 
 grounds into which alluvial peat is drifted, it is found forty 
 feet thick, and upwards ; but in such cases it generally owes 
 one half of its volume to the water which it contains. It 
 has seldom, if ever, been discovered within the tropics ; and 
 it rarely occurs in the valleys, even in the south of France 
 and Spain. It abounds more and more, in proportion as we 
 advance farther from the equator, and becomes not only 
 more frequent but more inflammable in northern latitudes. 
 
 * For a catalogue of plants which f Irish Bog Eeports, p. 209. 
 
 form peat, see Eev. Dr. Eennie's Essays J System of Geology, vol. ii. p. 353. 
 
 on Peat, p. 171; and Dr. MacCulloch's Rev. Dr. Eennie on Peat, p. 260. 
 Western Isles, vol. i. p. 129. 
 
CK. XLIV.] BLOWN SAND, AND VOLCANIC EJECTIONS. 497 
 
 The same phenomenon is repeated in the southern hemi- 
 sphere. No peat is found in Brazil, nor even in the swampy 
 parts of the country drained by the La Plata on the east 
 side of South America, or in the island of Chiloe on the 
 west ; yet when we reach the 45th degree of latitude and 
 examine the Chonos Archipelago or the Falkland Islands, 
 and Tierra del Fuego, we meet with an abundant growth of 
 this substance. Almost all plants contribute here by their 
 decay to the production of peat, even the grasses ; but it is 
 a singular fact, says Mr. Darwin, as contrasted with what 
 occurs in Europe, that no kind of moss enters into the com- 
 position of the South American peat, which is formed by 
 many plants, but chiefly by that called by Brown Astelia 
 pumila.* 
 
 I learnt from the late Dr. Forchhammer, in 1849, that water 
 charged with vegetable matter in solution does not throw 
 down a deposit of peat in countries where the mean tempera- 
 ture of the year is above 43 or 44 Fahrenheit. Frost 
 causes the precipitation of such peaty matter, but in warm 
 climates the attraction of the carbon for the oxygen of the 
 air mechanically mixed with the water increases with the 
 increasing temperature, and the dissolved vegetable matter 
 or humic acid (which is organic matter in a progressive state 
 of decomposition) being converted into carbonic acid, rises 
 and is absorbed into the atmosphere, and thus disappears. 
 
 Extent of surface covered by peat. There is a vast extent 
 of surface in Europe covered with peat, which, in Ireland, is 
 said to spread over a tenth of the whole island. One of the 
 mosses on the Shannon is described as being fifty miles long, 
 by two or three broad ; and the great marsh of Montoire, 
 near the mouth of the Loire, is mentioned by Blavier, as 
 being more than fifty leagues in circumference. According to 
 Eennie, many of these mosses of the north of Europe occupy 
 the place of forests of pine and oak, which have, many of 
 them, disappeared within the historical era. Such changes 
 are brought about by the fall of trees and the stagnation of 
 water, caused by their trunks and branches obstructing the 
 
 * Darwin's Journal, p. 349 ; 2nd ed. p. 287. 
 VOL. II. K K 
 
498 ENCLOSING OF FOSSILS IN PEAT, [On. XLIV. 
 
 free drainage of the atmospheric waters, and giving rise to 
 a marsh. In a warm climate, such decayed timber wonld 
 immediately be removed by insects, or by putrefaction ; but, 
 in the cold temperature now prevailing in our latitudes, 
 many examples are recorded of marshes originating in this 
 source. Thus, in Mar forest, in Aberdeenshire, large trunks 
 of Scotch fir, which had fallen from age and decay, are said 
 to have been soon immured in peat, formed partly out of 
 their perishing leaves and branches, and in part from the 
 growth of other plants. We are also told that the overthrow 
 of a forest by a storm, about the middle of the seventeenth 
 century, gave rise to a peat-moss near Lochbroom, in Ross- 
 shire, and that, in less than half a century after the fall of the 
 trees, the inhabitants dug peat there.*" But the rate at which 
 peat is known to form in places where its growth has been 
 carefully noted by scientific observers, is so slow that it is 
 necessary to receive these accounts with caution. 
 
 Nothing is more common than the occurrence of buried 
 trees at the bottom of the Irish peat-mosses, as also in most 
 of those of England, France, and Holland ; and they have 
 been so often observed with parts of their trunks standing 
 erect, and with their roots fixed to the subsoil, that no doubt 
 can be entertained of their having generally grown on the 
 spot. They consist, for the most part, of the fir, the oak, 
 and the birch: where the subsoil is clay, the remains of 
 oak are the most abundant ; where sand is the substratum, 
 fir prevails. In the marsh of Curragh, in the Isle of Man, 
 vast trees are discovered standing firm on their roots, though 
 at the depth of eighteen or twenty feet below the surface. 
 Some naturalists have desired to refer the imbedding of 
 timber in peat-mosses to aqueous transportation, since rivers 
 are well known to float wood into lakes ; but the facts above 
 mentioned show that, in numerous instances, such an hy- 
 pothesis is inadmissible. It has,' moreover, been observed, 
 that in Scotland, as also in many parts of the Continent, 
 the largest trees are found in those peat-mosses which lie in 
 the least elevated regions, and that the trees are propor- 
 
 * Kennie's Essays on Peat, p. 65. 
 
CH. XLIV.] BLOWN SAND, AND VOLCANIC EJECTIONS. 499 
 
 tionally smaller in those which lie at higher levels ; from 
 which fact De Luc and Walker have both inferred that the 
 trees grew on the spot, for they would naturally attain a 
 greater size in lower and warmer levels. The leaves, also, 
 and fruits of each species, are continually found immersed 
 in the moss along with the parent trees ; as, for example, 
 the leaves and acorns of the oak, the cones and leaves of the 
 fir, and the nuts of the hazel. 
 
 Supposed recent origin of some peat-mosses. In Hatfield 
 moss, in Yorkshire, which appears clearly to have been a 
 forest eighteen hundred years ago, fir-trees have been found 
 90 feet long, and sold for masts and keels of ships; oaks have 
 also been discovered there above 100 feet long. The dimen- 
 sions of an oak from this moss are given in the Philosophical 
 Transactions, No. 275, which must have been larger than 
 any tree now existing in the British dominions. 
 
 In the same moss of Hatfield, as well as in that of Kin- 
 cardine, in Scotland, and several others, Roman roads are 
 said to have been found covered to the depth of eight feet 
 by peat, and it has also been affirmed that all the coins, 
 axes, arms, and other utensils found in British and French 
 mosses, are Roman. But the more careful examinations 
 made of late years of the deposits of peat about 30 feet thick 
 at Amiens, Abbeville, and other places in the valley of the 
 Sornrne, lead me to distrust the inferences formerly drawn as 
 o the age of a large portion of the European peat, which 
 las been supposed to be of later date than the time of 
 ulius Caesar. M. Boucher de Perthes has ascertained that 
 Gallo-Roman remains occur at Abbeville, in peat nearer the 
 urface than the more ancient weapons called Celts of the 
 Stone Period. The same antiquary also remarks that the 
 Lepth at which Eoman works of art are met with, is not 
 always a sure test of age, because in some parts of the 
 swamp, especially near the river, the peat is often so fluid 
 hat heavy substances may sink through it.* Recent re- 
 earches may be said to have demonstrated that no small 
 art of the European peat is pre-Roman and belongs to the 
 
 * See ' Antiquity of Man,' p. 110. 
 KK 2 
 
500 ENCLOSING OF FOSSILS IN PEAT, [Cn. XLIV. 
 
 age of bronze instruments, and even in great part to the 
 antecedent Neolithic Stone Period, of which more will be 
 said in Chapter XL VII. 
 
 According to De Luc, the very site of the aboriginal forests 
 of Hercinia, Semana, Ardennes, and several others, are now 
 occupied by mosses and fens. A great part of these changes 
 have, with much probability, been attributed to the strict 
 orders given by Severus, and other emperors, to destroy all 
 the wood in the conquered provinces. So also many of the 
 British forests, which are now mosses, were cut at different 
 periods, by order of the English parliament, because they 
 harboured wolves or outlaws. Thus the Welsh woods were 
 cut and burnt, in the reign of Edward I. ; as were many of 
 those in Ireland, by Henry II., to prevent the natives from 
 harbouring in them, and harassing his troops. 
 
 It is a remarkable fact that in the Danish islands, and in 
 Jutland as well as in Holstein, trunks of the Scotch fir, Pinus 
 sylvestris, are found at the bottom of the peat-mosses, al- 
 though this species of fir has not been a native of the same 
 countries in historical times, and, when introduced there, has 
 not thriven. Higher up in the Danish peat-mosses, prostrate 
 trunks of the sessile variety of the common oak occur, while 
 at a still higher level, the pedunculated variety of the same 
 oak, Quercus robur, Linn., is met with, together with the 
 alder, birch, and hazel. The oak has now in its turn been 
 almost supplanted in Denmark by the common beech. There 
 appears therefore to have been a natural rotation of trees, 
 whether owing to the exhaustion of the soil, or a change of 
 climate in Denmark ; one set of species, which lived on the 
 borders of the swamps, having died out and another suc- 
 ceeded. These changes took place, all of them, before the 
 historical era ; but remains of man have been found even in 
 the fundamental peat in which the Scotch firs lie buried, and 
 a flint implement has been taken out, by Steenstrup himself, 
 from below one of the buried pines. It was a weapon o: 
 the later Stone Period or Neolithic Age no remains 
 Paleolithic Man having as yet been discovered in any part 
 of Scandinavia.* 
 
 * Lubbock, introduction to Nilsson on the Stone Age, 1568. 
 
CH. XLIV.] BLOWN SAND, AND VOLCANIC EJECTIONS. 501 
 
 Sources of bog iron-ore. At the bottom of peat-mosses 
 there is sometimes found a cake, or ' pan,' as it is termed, of 
 oxide of iron, and the frequency of bog iron-ore is familiar 
 to the mineralogist. The oak, which is so often dyed black 
 in peat, owes its colour to the same metal. From what 
 source the iron is derived has often been a subject of dis- 
 cussion, until the discoveries of Ehrenberg seem at length to 
 have removed the difficulty. He had observed, in the marshes 
 about Berlin, a substance of a deep ochre yellow passing 
 into red, which covered the bottom of the ditches, and 
 which, where it had become dry after the evaporation of the 
 water, appeared exactly like oxide of p. 139 
 
 iron. But under the microscope it was 
 found to consist of slender articulated 
 threads or plates, partly siliceous and 
 partly ferruginous, of a plant of simple 
 structure, Gallionella ferruginea, of the Gainoneiia fe 
 family called Diatomacea}.* There can a ' 200 times magnified - 
 be little doubt, therefore, that bog iron-ore consists of an 
 aggregate of millions of these organic bodies invisible to the 
 naked eye.f 
 
 Preservation of animal substances in peat. One interesting 
 circumstance attending the history of peat-mosses is the 
 high state of preservation of animal substances buried in 
 them for periods of many years. In June, 1747, the body of 
 a woman was found six feet deep, in a peat-moss in the Isle 
 of Axholm, in Lincolnshire. The antique sandals on her 
 feet afforded evidence of her having been buried there for 
 many centuries ; yet her nails, hair, and skin are described 
 as having shown hardly any marks of decay. On the estate 
 of the Earl of Moira, in the north of Ireland, a human body 
 was dug up, a foot deep in gravel, covered with eleven feet 
 of peat ; the body was completely clothed and the garments 
 seemed all to be made of hair. Before the use of wool 
 was known in that country the clothing of the inhabitants 
 was made of hair, so that it would appear that this body 
 had been buried at that early period ; yet it was fresh and 
 
 * See above. Vol. I. p. 644. 
 
 f Ehrenberg, Taylor's Scientific Mem., vol. i. part iii. p. 402. 
 
502 ENCLOSING OF FOSSILS IN PEAT, [Cn. XLIV. 
 
 unimpaired."^ In the Philosophical Transactions we find an 
 example recorded of the bodies of two persons having been 
 buried in moist peat, in Derbyshire, in 1674, about a yard 
 deep, which were examined twenty- eight years and nine 
 months afterwards ; 6 the colour of their skin was fair and 
 natural, their flesh soft as that of persons newly dead.'f 
 
 Among other analogous facts we may mention, that in 
 digging a pit for a well near Dulverton, in Somersetshire, 
 many pigs were found in various postures, still entire. Their 
 shape was well preserved, the skin, which retained the hair, 
 having assumed a dry, membranous appearance. Their 
 whole substance was converted into a white, friable, lami- 
 nated, inodorous, and tasteless substance ; but which, when 
 exposed to heat, emitted an odour precisely similar to broiled 
 bacon. J 
 
 Cause of the antiseptic property of peat. We naturally ask 
 whence peat derives this antiseptic property ? It has been 
 attributed by some to the carbonic and gallic acids which 
 issue from decayed wood, as also to the presence of charred 
 wood in the lowest strata of many peat-mosses, for charcoal 
 is a powerful antiseptic, and capable of purify ing water already 
 putrid. Vegetable gums and resins also may operate in the 
 same way. 
 
 The tannin occasionally present in peat is the produce, 
 says Dr. MacCulloch, of tormentilla, and some other plants ; 
 but the quantity he thinks too small, and its occurrence too 
 casual, to give rise to effects of any importance. He hints 
 that the soft parts of animal bodies, preserved in peat-bogs, 
 may have been converted into adipocire by the action of 
 water merely. || 
 
 Miring of quadrupeds. The manner, however, in which 
 peat contributes to preserve, for indefinite periods, the harder 
 parts of terrestrial animals, is a subject of more immediate 
 interest to the geologist. There are two ways in which 
 animals become occasionally buried in the peat of marshy 
 grounds ; they either sink down into the semifluid mud, 
 
 * Dr. Rennie, on Peat, p. 521 ; where J Dr. Eennie, on Peat, &c., p. 521. 
 
 several other instances are referred to. Ibid. p. 531. 
 
 t Phil. Trans, vol. xxxviii. 1734. j| Syst. of Geol. vol. ii. pp. 340346. 
 
CH. XLIV.] BLOWN SAND, AND VOLCANIC EJECTIONS. 503 
 
 underlying a turfy surface upon which they have rashly 
 ventured, or, at other times, as we shall see in the sequel, 
 a bog ' bursts,' and animals may be involved in the peaty 
 alluvium. 
 
 In the extensive bogs of Newfoundland, cattle are some- 
 times found buried alive with only their heads and necks 
 above ground ; and after having remained for days in this 
 situation, they have been drawn out by ropes and saved. In 
 Scotland, also, cattle venturing on the ' quaking moss,' are 
 often mired, or ' laired,' as it is termed ; and in Ireland, Mr. 
 King asserts that the number of cattle which are lost in 
 sloughs is quite incredible.* 
 
 Solway moss. The description given of the Solway moss 
 will serve to illustrate the general character of these boggy 
 grounds. That moss, observes Gilpin, is a flat area, about 
 seven miles in circumference, situated on the western confines 
 of England and Scotland. Its surface is covered with grass 
 and rushes, presenting a dry crust and a fair appearance ; 
 but it shakes under the least pressure, the bottom being 
 unsound and semifluid. The adventurous passenger, there- 
 fore, who sometimes in dry seasons traverses this perilous 
 waste, to save a few miles, picks his cautious way over the 
 rushy tussocks as they appear before him, for here the 
 soil is firmest. If his foot slip, or if he venture to desert 
 this mark of security, it is possible he may never more be 
 heard of. 
 
 6 At the battle of Solway, in the time of Henry VIII. (1542), 
 when the Scotch army, commanded by Oliver Sinclair, was 
 routed, an unfortunate troop of horse, driven by their fears, 
 plunged into this morass, which instantly closed upon them. 
 The tale was traditional, but it is now so far authenticated, 
 that a man and horse, in complete armour, have been 
 found by peat-diggers, in the place were it was always sup- 
 posed the affair had happened. The skeleton of each was well 
 preserved, and the different parts of the armour easily distin- 
 guished.'f 
 
 The same moss, on the 16th of December, 1772, having 
 
 * Phil. Trans, vol. xv. p. 949. 
 
 f Gilpin, Observ. on Picturesque Beauty, &c., 1772. 
 
504 ENCLOSING OF FOSSILS IN PEAT, [Cn. XLIV. 
 
 been filled like a great sponge with water during heavy rains, 
 swelled to an unusual height above the surrounding country, 
 and then burst. The turfy covering seemed for a time to act 
 like the skin of a bladder retaining the fluid within, till it 
 forced a passage for itself, when a stream of black half-con- 
 solidated mud began at first to creep over the plain, resemb- 
 ling, in the rate of its progress, an ordinary lava-current. 
 No lives were lost, but the deluge totally overwhelmed some 
 cottages, and covered 400 acres. The highest parts of the 
 original moss subsided to the depth of about 25 feet ; and 
 the height of the moss, on the lowest parts of the country 
 which it invaded, was at least 15 feet. 
 
 Bursting of peat-mosses. An inundation in Sligo in Jan- 
 uary, 1831, affords another example of this phenomenon. 
 After a sudden thaw of snow, the bog between Bloomfield 
 and Geevah gave way ; and a black deluge, carrying with it 
 the contents of a hundred acres of bog, took the direction of 
 a small stream and rolled on with the violence of a torrent, 
 sweeping along heath, timber, mud, and stones, and over- 
 whelming many meadows and arable land. On passing 
 through some boggy land, the flood swept out a wide and 
 deep ravine, and part of the road leading from Bloomfield 
 to St. James's Well was completely carried away from below 
 the foundation for the breadth of 200 yards. 
 
 An ancient log-cabin is recorded as having been found in 
 1833 at the depth of fourteen feet in the peat of Donegal in 
 Ireland. The cabin was filled with peat and was surrounded 
 by other huts, which were not examined. The trunks and 
 roots of trees preserved in their natural position surrounded 
 these huts. There can be little doubt that we have here an 
 example of a village which at some unknown period was 
 overwhelmed by the bursting of a moss. In such cases the 
 depth of vegetable matter which may overlie the dwelling 
 affords no test of antiquity, as the whole thickness may have 
 accumulated at once when the catastrophe occurred. 
 
 From the facts before mentioned, respecting the burst- 
 ing of mosses and the manner in which they frequently 
 descend in a fluid state to lower levels, the reader will readily 
 perceive that lakes and arms of the sea must occasionally 
 
CH. XLIV.] BLOWN SAND, AND VOLCANIC EJECTIONS. 505 
 
 become the receptacles of drift peat. Of this, accordingly, 
 there are numerous examples ; and hence the alternations of 
 clay and sand with different deposits of peat so frequent on 
 some coasts, as on those of the Baltic and German Ocean. 
 We are informed by Deguer, that remains of ships, nautical 
 instruments, and oars, have been found in many of the Dutch 
 mosses. Gerard has shown by similar proofs that many 
 mosses on the coast of Picardy, Zealand, and Friesland were 
 at one period navigable arms of the sea. 
 
 Bones of herbivorous quadrupeds in peat. The antlers of 
 large and full-grown stags are amongst the most common 
 and conspicuous remains of animals in peat. They are not 
 horns which have been shed ; for portions of the skull are 
 found attached, proving that the whole animal perished. 
 Bones of the ox, hog, horse, sheep, and other herbivorous 
 animals, also occur. M. Morren has discovered in the peat 
 of Flanders the bones of otters and beavers,"* and M. Boucher 
 de Perthes has found bones and teeth of the Ursus Arctos, 
 or the bear which now lives in the Pyrenees, in the peat 
 of Abbeville. But as a general rule no remains are met 
 with belonging to extinct quadrupeds, such as the elephant, 
 rhinoceros, hippopotamus, hysena, and tiger, which are so 
 common in old European river-gravels. 
 
 Bones of the mammoth mentioned by us in the first volume, 
 pp. 544, 545, as occurring in peat and vegetable matter of 
 older date than ordinary peat-mosses, are very exceptional. 
 The great extinct deer also, Cervus Megaceros, has often been 
 said to have been dug out of peat, but its true position seems 
 to be in shell-marl underlying peat-mosses. The freshwater 
 shells of such marl and others occasionally associated with 
 peat, as well as the landshells met with in the same, are in- 
 variably of species now living. 
 
 Great Dismal Swamp. I have described in my 'Travels in 
 North America,' f an extensive swamp or morass, 40 miles 
 long from north to south, and 25 wide, between the 
 towns of Norfolk in Virginia, and Weldon in North Caro- 
 lina. It is called the f Great Dismal,' and has somewhat the 
 
 * Bulletin dela Soc. Geol. de France, f Travels, &c., in 1841, 1842, vol. i. 
 
 torn. ii. p. 26. p. 143. 
 
506 ENCLOSING OF FOSSILS IN PEAT, [Cir. XLIY. 
 
 appearance of an inundated river-plain covered with aquatic 
 trees and shrubs, the soil being as black as that of a peat-bog. 
 It is higher on all sides except one than the surrounding 
 country, towards which it sends forth streams of water to the 
 north, east, and south, receiving a supply from the west only. 
 In its centre it rises 12 feet above the flat region which 
 bounds it. The soil, to the depth of 15 feet, is formed of 
 vegetable matter without any admixture of earthy particles, 
 and offers an exception to a general rule before alluded to, 
 namely, that such peaty accumulations scarcely ever occur so 
 far south as lat. 36, or in any region where the summer heat 
 is so great as in Virginia. In digging canals through the 
 morass for the purpose of obtaining timber, much of the 
 black soil has been thrown out from time to time, and 
 exposed to the sun and air, in which case it soon rots away 
 so that nothing remains behind, showing clearly that it owes 
 its preservation to the shade afforded by a luxuriant vegeta- 
 tion and to the constant evaporation of the spongy soil by 
 which the air is cooled during the hot months. The surface 
 of the bog is carpeted with mosses, and densely covered 
 with ferns and reeds, above which many evergreen shrubs 
 and trees flourish, especially the White Cedar (Gupressus 
 thyoides), which stands firmly supported by its long tap roots 
 in the softest parts of the quagmire. Over the whole the 
 deciduous Cypress (Taxodium distichum) is seen to tower with 
 its spreading top, in full leaf in the season when the sun's 
 rays are hottest, and when, if not intercepted by a screen of 
 foliage, they might soon cause the fallen leaves and dead 
 plants of the preceding autumn to decompose, instead of 
 adding their contributions to the peaty mass. On the sur- 
 face of the whole morass lie innumerable trunks of large 
 and tall trees blown down by the winds, while thousands of 
 others are buried at various depths in the black mire below. 
 They remind the geologist of the prostrate position of large 
 stems of Sigillaria and Lepidodendron, converted into coal in 
 ancient carboniferous rocks. 
 
:n. XLIV.] BLOWN SAND, AND VOLCANIC EJECTIONS. 507 
 
 EMBEDDING OF HUMAN AND OTHER REMAINS, AND WORKS OF 
 ART, IN BLOWN SAND. 
 
 The drifting of sand may next be considered among the 
 causes capable of preserving organic remains and works of 
 art on the emerged land. 
 
 African sands. The sands of the African deserts have 
 been driven by the west winds over part of the arable land 
 of Egypt, on the western bank of the Mle, in those places 
 where valleys open into the plain, or where there are gorges 
 through the Libyan mountains. By similar sand-drifts the 
 ruins of ancient cities have been buried between the temple 
 of Jupiter Ammon and Nubia. 
 
 We have seen that Sir J. G. Wilkinson is of opinion that, 
 while the sand-drift is making aggressions at certain points 
 upon the fertile soil of Egypt, the alluvial deposit of the 
 N ile is advancing very generally upon the desert ; and that, 
 upon the whole, the balance is greatly in favour of the ferti- 
 lising mud.* 
 
 JSTo mode of interment can be conceived more favourable 
 to the conservation of monuments for indefinite periods than 
 that now so common in the region immediately westward of 
 the plain of the Mle. The sand which surrounded and filled 
 the great temple of Ipsambul, first discovered by Burckhardt, 
 itiid afterwards partially uncovered by Belzoni and Beechey, 
 was so fine as to resemble a fluid when put in motion. 
 Neither the features of the colossal figures, nor the colour of 
 the stucco with which some were covered, nor the paintings 
 on the walls, had received any injury from being enveloped 
 for ages in this dry inpalpable dust.f 
 
 At some future period, perhaps when the pyramids shall 
 have perished, the action of the sea, or an earthquake, may 
 lay open to the day some of these buried temples. Or we may 
 suppose the desert to remain undisturbed, and changes in the 
 surrounding sea and land to modify the climate and the 
 direction of the prevailing winds, so that these may then 
 
 * See p. 433. t Stratton, Ed. Phil. Journ., No. v. p. 62. 
 
508 ENCLOSING OF FOSSILS IN PEAT, [Cn. XLIV. 
 
 waft away the Libyan sands as gradually as they once brought 
 them to those regions. 
 
 Whole caravans are said to have been overwhelmed by the 
 Libyan sands ; and Burckhardt informs us that ' after pass- 
 ing the Akaba near the head of the Red Sea, the bones of 
 dead camels are the only guides of the pilgrim through the 
 wastes of sands.' f We did not see,' says Captain Lyon, 
 speaking of a plain near the Soudah mountains, in Northern 
 Africa, ' the least appearance of vegetation ; but observed 
 many skeletons of animals, which had died of fatigue on the 
 desert, and occasionally the grave of some human being. 
 All these bodies were so dried by the heat of the sun, that 
 putrefaction appears not to have taken place after death. 
 In recently expired animals I could not perceive the slightest 
 offensive smell ; and in those long dead, the skin with the 
 hair on it remained unbroken and perfect, although so brittle 
 as to break with a slight blow. The sand- winds never cause 
 these carcasses to change their places ; for, in a short time, 
 a slight mound is formed round them, and they become 
 stationary.'* 
 
 Towns overwhelmed by sand floods. The burying of several 
 towns and villages in England, France, and Jutland, by 
 blown sand is on record ; thus, for example, near St. Pol de 
 Leon, in Brittany, a whole village was completely buried 1 
 beneath drift sand, so that nothing was seen but the spire of 
 the church. f In Jutland marine shells adhering to sea- 
 weed are sometimes blown by the violence of the wind to the 
 height of 100 feet and buried in similar hills of sand. 
 
 In Suffolk, in the year 1688, part of Downham was over- 
 whelmed by sands which had broken loose about 100 yearsi 
 before, from a warren five miles to the south-west. . This 
 sand had, in the course of a century, travelled five miles, and 
 covered more than 100 acres of land. J A considerable traci 
 of cultivated land on the north coast of Cornwall has been 
 inundated by drift sand, forming hills several hundred feel 
 above the level of the sea, and composed of comminutec 
 
 * Travels in North Africa in the 1772. See also the case of the burie 
 Years 1818, 1819, and 1820, p. 83. church of Eccles, Vol. I. p. 513. 
 
 t Mem. de 1'Acad. des Sci. de Paris, J Phil. Trans, vol. ii. p. 722. 
 
CH. XLIV.] BLOWN" SAXD, AND VOLCANIC EJECTIONS. 500 
 
 marine shells, in which some terrestrial shells are enclosed 
 entire. By the shifting of these sands the ruins of ancient 
 buildings have been discovered ; and in some cases where 
 wells have been bored to a great depth, distinct strata, separ- 
 ated by a vegetable crust, are visible. In some places, as at 
 New Quay, large masses have become sufficiently indurated 
 to be used for architectural purposes. The lapidification, 
 which is still in progress, appears to be due to oxide of 
 iron held in solution by the water which percolates the 
 sand.* 
 
 IMBEDDING OF ORGANIC AND OTHER REMAINS IN VOLCANIC 
 FORMATIONS ON THE LAND. 
 
 I have in some degree anticipated the subject of this sec- 
 tion in former chapters, when speaking of the buried cities 
 around Naples, and those on the flanks of Etna.f From the 
 facts referred to, it appeared that the preservation of human 
 remains and works of art is frequently due to the descent of 
 floods caused by the copious rains which accompany erup- 
 tions. These aqueous lavas, as they are called in Campania, 
 flow with great rapidity ; and in 1822 surprised and suffo- 
 cated seven persons in the villages of St. Sebastian and 
 Massa, on the flanks of Vesuvius. 
 
 In the tuffs, moreover, or solidified mud, deposited by 
 these aqueous lavas, impressions of leaves and of trees have 
 been observed. Some of those, formed after the eruption 
 of Vesuvius in 1822, are now preserved in the museum at 
 Naples. 
 
 Lava itself may become indirectly the means of preserving 
 terrestrial remains, by overflowing beds of ashes, pumice, and 
 ejected matter, which may have been showered down upon 
 animals and plants, or upon human remains. Few substances 
 are better non-conductors of heat than volcanic dust and 
 scoriae, so that a bed of such materials is rarely melted by a 
 superimposed lava-current. After consolidation, the lava 
 affords secure protection to the lighter and more removable 
 
 * Boase on Submersion of Part of the of Cornwall, vol. ii. p. 140. 
 Mount's Bay, &c., Trans. Roy. Geol. -Sue. f Vol. I. p. 640, and Vol. II. p. 22. 
 
510 ENCLOSING OF FOSSILS IN PEAT, ETC. [Cn. XLIV. 
 
 mass below, in which the organic relics may be enveloped. 
 The Herculanean tuffs containing the rolls of papyrus, of 
 which the characters are still legible, have, as was before 
 remarked, been for ages covered by lava. 
 
 Another mode by which lava may tend to the conservation 
 of imbedded remains, at least of works of human art, is by its 
 overflowing them when it is not intensely heated, in which 
 case they sometimes suffer little or no injury. 
 
 Thus when the Etnean lava-current of 1669 covered four T 
 teen towns and villages, and part of the city of Catania, it did 
 not melt down a great number of statues and other articles 
 in the vaults of Catania; and at the depth of 35 feet in 
 the same current, on the site of Mompiliere, one of the buried 
 towns, the bell of a church and some statues were found 
 uninjured (p. 24). 
 
 
511 
 
 CHAPTER XLV. 
 
 BURYING OP FOSSILS IN ALLUVIAL DEPOSITS AND IN CAVES. 
 
 FOSSILS IN ALLUVIUM EFFECTS OF SUDDEN INUNDATIONS TERRESTRIAL ANIMALS 
 
 MOST ABUNDANTLY PRESERVED IN ALLUVIUM WHERE EARTHQUAKES PREVAIL 
 
 MARINE ALLUVIUM BURIED TOWNS EFFECTS OF LANDSLIPS ORGANIC RE- 
 MAINS IN FISSURES AND CAVES FORM AND DIMENSIONS OF CAVERNS 
 
 THEIR PROBABLE ORIGIN CLOSED BASINS AND SUBTERRANEAN RIVERS OF 
 
 THE MOREA KATAVOTHRA FORMATION OF BRECCIAS WITH RED CEMENT 
 
 HUMAN REMAINS IMBEDDED IN MOREA SCHMERLING ON INTERMIXTURE OF 
 
 HUMAN REMAINS AND BONES OF EXTINCT QUADRUPEDS AS PROVING THE 
 
 FORMER CO-EXISTENCE OF MAN WITH THOSE LOST SPECIES BONE-BRECCIAS 
 
 FORMED IN OPEN FISSURES AND CAVES. 
 
 FOSSILS ix ALLUVIUM. The next subject for our considera- 
 tion, according to the division before proposed, is the imbed- 
 ding of organic bodies in alluvium. 
 
 The gravel, sand, and mud in the bed of a river does not 
 often contain any animal or vegetable remains; for the 
 whole mass is so continually shifting its place, and the 
 attrition of the various parts is so great, that even the 
 hardest rocks contained in it are, at length, ground down to 
 powder. But when sand and sediment are swept by a flood 
 over lands bordering a river, such an alluvium may envelop 
 trees or the remains of animals, which, in this manner, are 
 often permanently preserved. In the mud and sand pro- 
 ! duced by the floods in Scotland, in 1829, the dead and 
 mutilated bodies of hares, rabbits, moles, mice, partridges, 
 d even the bodies of men, were found partially buried.* 
 But in these and similar cases one flood usually effaces 
 }he memorials left by another, and it is only when rivers 
 are eroding and deepening valleys that portions of old river 
 channels are left high and dry beyond the reach of floods, in 
 which case the organic remains may be preserved for ages 
 
 * Sir T. D. Lander, Bart., on Floods in Morayshire, Aug. 1839, p.Jl77. 
 
512 BUEYING OF FOSSILS IN [Cn. XLV. 
 
 In districts repeatedly deranged by earthquakes rivers often 
 shift their channels from one part of a valley to another, 
 and alluvial accumulations caused by transient floods become 
 permanent depositaries of organic substances. 
 
 Marine alluvium. In May, 1787, a dreadful inundation of 
 the sea was caused at Coringa, Ingeram, and other places, 
 on the coast of Coromandel, in the East Indies, by a hurri- 
 cane blowing from the NE., which raised the waters so that 
 they rolled inland to the distance of about twenty miles from 
 the shore, swept away many villages, drowned more than 
 10,000 people, and left the country covered with marine mud, 
 on which the carcasses of about 100,000 head of cattle were 
 strewed. An old tradition of the natives of a similar flood, 
 said to have happened about a century before, was, till this 
 event, regarded as fabulous by the European settlers.* The 
 same coast of Coromandel was, so late as May, 1832, the 
 scene of another catastrophe of the same kind ; and when 
 the inundation subsided, several vessels were seen grounded 
 in the fields of the low country about Coringa. 
 
 Many of the storms termed hurricanes have evidently been 
 connected with submarine earthquakes, as shown by the 
 atmospheric phenomena attendant on them, and by the 
 sounds heard in the ground and the odours emitted. 
 
 Houses and works of art in alluvial deposits. A very ancient 
 subterranean town, apparently of Hindoo origin, was dis- 
 covered in India in 1833, in digging the Doab canal. Its 
 site is north of Saharunpore, near the town of Behat, 
 and 17 feet below the present surface of the country. 
 More than 170 coins of silver and copper were found, and 
 many articles in metal and earthenware. The overlying 
 deposit consisted of about 5 feet of river sand, with a 
 substratum, about 12 feet thick, of red alluvial clay. In 
 the neighbourhood are several rivers and torrents, which 
 descend from the mountains charged with vast quantities 
 of mud, sand, and shingle ; and within the memory of persons 
 now living the modern Behat has been threatened by an 
 inundation, which, after retreating, left the neighbouring 
 
 * Dodsley's Ann. Kegist., 1788. 
 
CH. XLV.] ALLUVIAL DEPOSITS AND CAVES. 513 
 
 country strewed over with a superficial covering of sand 
 several feet thick. In sinking wells in the environs, masses 
 of shingle and boulders have been reached resembling those 
 now in the river- channels of the same district, under a 
 deposit of thirty feet of reddish loam. Captain Cautley, 
 therefore, who directed the excavations, supposes that the 
 matter discharged by torrents has gradually raised the whole 
 country skirting the base of the lower hills ; and that the 
 ancient town, having been originally built in a hollow, was 
 submerged by floods, and covered over with sediment seven- 
 teen feet in thickness.* 
 
 We are informed, by M. Boblaye, that in the Morea, the 
 formation termed ceramique, consisting of pottery, tiles, and 
 bricks, intermixed with various works of art, enters so 
 largely into the alluvium and vegetable soil upon the plains 
 of Greece, and into hard and crystalline breccias which have 
 been formed at the foot of declivities, that it constitutes 
 an important stratum which might, even in the absence of 
 zoological characters, serve to mark part of the human epoch 
 in a most indestructible manner.-f- 
 
 Landslips. The landslip, by suddenly precipitating large 
 
 masses of rock and soil into a valley, overwhelms a multitude 
 
 of animals, and sometimes buries permanently whole villages, 
 
 with their inhabitants and large herds of cattle. Thus three 
 
 villages, with their entire population, were covered, when the 
 
 mountain of Piz fell in 1772, in the district of Treviso, in 
 
 the state of Venice, J and part of Mount Grenier, south of 
 
 hambery, in Savoy, which fell down in the year 1248, 
 
 uried five parishes, including the town and church of St. 
 
 Jidre, the ruins occupying an extent of about nine square 
 
 liles. 
 
 The number of lives lost by the slide of the Rossberg, in 
 witzerland, in 1806, was estimated at more than 800, a 
 reat number of the bodies, as well as several villages and 
 3attered houses, being buried deep under mud and rock. 
 
 * Journ. of Asiat. Sue., Nos. xxv. and J Malte-Brun's Geog., vol. i. p. 435. 
 
 i ., 1 834. Bakewell, Travels in the Tarentaise, 
 
 t Ann. des Sci. Nat., torn. xxii. p. vol. i. p. 201. 
 17, Feb. 1831. 
 
 VOL. II. L L 
 
514 BURYING OF FOSSILS IN [On. XLV. 
 
 In the same country, several hundred cottages, with eighteen 
 of their inhabitants and a great number of cows, goats, and 
 sheep, were victims to the sudden fall of a bed of stones, 
 thirty yards deep, which descended from the summits of the 
 Diablerets in Yallais. In the year 1618, a portion of Mount 
 Conto fell, in the county of Chiavenna, in Switzerland, and 
 buried the town of Pleurs, with all its inhabitants, to the 
 number of 2,430. 
 
 It is unnecessary to multiply examples of similar local 
 catastrophes, which have been very numerous in mountainous 
 parts of Europe, within the historical period, more especially 
 in regions convulsed by earthquakes. It is there that enor- 
 mous masses of rock and earth, even in comparatively low 
 and level countries, are detached from the sides of valleys, 
 and cast down into the river courses, and often so unexpect- 
 edly that they overwhelm, even in the daytime, every living 
 thing upon the plains. 
 
 PRESERVATION OP ORGANIC REMAINS IN FISSURES AND CAVES. 
 
 In the history of earthquakes it was shown that many 
 hundreds of new fissures and chasms had opened in certain 
 regions during the last 150 years, some of which are 
 described as being of unfathomable depth. We also perceive 
 that mountain masses have been violently fractured and 
 dislocated, during their rise above the level of the sea ; and 
 thus we may account for the existence of many cavities in 
 the interior of the earth by the simple agency of earthquakes ; 
 but there are some caverns, especially in limestone rocks, 
 which, although usually, if not always, connected with rents, 
 are nevertheless of such forms, and dimensions, alternately 
 expanding into spacious chambers, and then contracting 
 again into narrow passages, that we cannot suppose them to 
 have owed their origin exclusively to the mere fracturing and 
 displacement of solid masses. 
 
 In the limestone of Kentucky, in the basin of Green Eiver, 
 one of the tributaries of the Ohio, a line of underground 
 cavities has been traced in one direction for a distance of 
 ten miles, without any termination ; and one of the chambers, 
 
CH. XLV.] ALLUVIAL DEPOSITS AND CAVES. 515 
 
 of which there are many, all connected by narrow tunnels, 
 is no less than ten acres in area, and 150 feet in its greatest 
 height. Besides the principal series of c antres vast,' there 
 are a great many lateral embranchments not yet explored.* 
 
 The cavernous structure here alluded to, is not altogether 
 confined to calcareous rocks ; for it has lately been observed 
 in micaceous and argillaceous schist in the Grecian island 
 of Thermia (Cythnos of the ancients), one of the Cyclades. 
 Here also spacious halls, with rounded and irregular walls, 
 are connected together by narrow passages or tunnels, and 
 there are many lateral branches which have no outlet. A 
 current of water has evidently at some period flowed through 
 the whole, and left a muddy deposit of bluish clay upon 
 the floor; but the erosive action of the stream cannot be 
 supposed to have given rise to the excavations in the first 
 instance. M. Virlet suggests that fissures were first caused 
 by earthquakes, and that these fissures became the chimneys 
 or vents for the disengagement of gas, generated below by 
 volcanic heat. Gases, he observes, such as the muriatic, 
 sulphuric, fluoric, and others, might, if raised to a high 
 temperature, alter and decompose the rocks which they 
 traverse. There are signs of the former action of such 
 vapours in rents of the micaceous schist of Thermia, and 
 thermal springs now issue from the grottos of that island. 
 We may suppose that afterwards the elements of the decom- 
 posed rocks were gradually removed in a state of solution by 
 mineral waters ; a theory which, according to M. Virlet, is 
 confirmed by the effect of heated gases which escape from 
 rents in the isthmus of Corinth, and which have greatly 
 altered and corroded the hard siliceous and jaspideous rocks.f 
 
 When we reflect on the quantity of carbonate of lime 
 annually poured out by mineral waters, we are prepared to 
 admit that large cavities must, in the course of ages, be 
 formed at considerable depths below the surface in calcareous 
 rocks 4 These rocks, it will be remembered, are at once 
 more soluble, more permeable, and more fragile, than any 
 
 * Nahum Ward, Trans, of Antiq. Soc. f Bull, de la Soc. Geol. de France, 
 
 of Massachusetts. Holmes's United torn. ii. p. 329. 
 States, p. 438. J See above, Vol. I. p. 401. 
 
 LL 2 
 
516 BURYING- OF FOSSILS IN [On. XLV. 
 
 others, at least all the compact varieties are very easily 
 broken by the movements of earthquakes, which would 
 produce only flexures in argillaceous strata. Fissures once 
 formed in limestone are not liable, as in many other forma- 
 tions, to become closed up by impervious clayey matter, and 
 hence a stream of acidulous water might for ages obtain a 
 free and unobstructed passage.* 
 
 Morea. Nothing is more common in limestone districts 
 than the engulfment of rivers, which after holding a sub- 
 terranean course of many miles escape again by some new 
 outlet. As they are usually charged with fine sediment, and 
 often with sand and pebbles where they enter, whereas they 
 are commonly pure and limpid where they flow out again, 
 they must deposit much matter in empty spaces in the 
 interior of the earth. In addition to the materials thus in- 
 troduced, stalagmite, or carbonate of lime, drops from the 
 roofs of caverns, and in such mixture the bones of animals 
 washed in by rivers are often entombed. In this manner we 
 may account for those bony breccias which we often find in 
 caves, some of which are of high antiquity while others are 
 very recent and in daily progress. In no district are engulfed 
 streams more conspicuous than in the Morea, where the 
 phenomena attending them have been studied and described 
 in great detail by M. Boblaye and his fellow-labourers of the 
 French expedition to Greece. f Their account is peculiarly 
 interesting to geologists, because it throws light on the red 
 osseous breccias containing the bones of extinct quadrupeds 
 which are so common in almost all the countries bordering 
 the Mediteiraiiean. It appears that the numerous caverns 
 of the Morea occur in a compact limestone, of the age of 
 the English chalk, immediately below which are arenaceous 
 strata referred to the period of our greensand. In the more 
 elevated districts of that peninsula there are many- "deep 
 land-locked valleys, or basins, closed round on all sides by 
 mountains of fissured and cavernous limestone. The year is 
 divided almost as distinctly as between the tropics into a 
 rainy season, which lasts upwards of four months, and a 
 
 * See remarks by M. Boblaye, Ann. f Ann. des Mines, 3me serie, torn. iv. 
 des Mines, 3me serie, torn. iv. 1833. 
 
CH. XLV.] ALLUVIAL DEPOSITS AND CAVES. 517 
 
 season of drought of nearly eight months' duration. When 
 the torrents are swollen by the rains, they rush from surround- 
 ing heights into the enclosed basins ; but, instead of giving 
 rise to lakes, as would be the case in most other countries, 
 they are received into gulfs or chasms, called by the Greeks 
 ' Katavothra,' and which correspond to what are termed 
 ' swallow-holes ' in the north of England. The water of 
 these torrents is charged with pebbles and red ochreous 
 earth, resembling precisely the well-known cement of the 
 osseous breccias of the Mediterranean. It dissolves in acids 
 with effervescence, and leaves a residue of hydrated oxide of 
 iron, granular iron, impalpable grains of silex, and small 
 crystals of quartz. Soil of the same description abounds 
 everywhere on the surface of the decomposing limestone in 
 Greece, that rock containing in it much siliceous and ferru- 
 ginous matter. 
 
 Many of the Katavothra being insufficient to give passage 
 to all the water in the rainy season, a temporary lake is 
 formed round the mouth of the chasm, which then becomes 
 still further obstructed by pebbles, sand, and red mud, thrown 
 down from the turbid waters. The lake being thus raised, 
 its waters generally escape through other openings, at higher 
 levels, around the borders of the plain, constituting the bottom 
 of the closed basin. 
 
 In some places, as at Kavaros and Tripolitza, where the 
 principal discharge is by a gulf in the middle of the plain, 
 nothing can be seen over the opening in summer, when the 
 lake dries up, but a deposit of red mud, cracked in all 
 directions. But the Katavothron is more commonly situated 
 at the foot of the surrounding escarpment of limestone ; 
 and in that case there is sometimes room enough to allow a 
 person to enter, in summer, and even to penetrate far into 
 the interior. Within is seen a suite of chambers, communi- 
 cating with each other by narrow passages ; and M. Virlet 
 relates, that in one instance he observed, near the entrance, 
 human bones imbedded in recent red mud, mingled with the 
 remains of plants and animals of species now inhabiting the 
 Morea. It is not wonderful, he says, that the bones of man 
 should be met with in such receptacles ; for so murderous 
 
518 BURYING OF FOSSILS IN [On. XLV. 
 
 have been the late wars in Greece, that skeletons are often 
 seen lying exposed on the surface of the country.* 
 
 In summer, when no water is flowing into the Katavothron, 
 its mouth, half closed up with red mud, is masked by a vigorous 
 vegetation, which is cherished by the moisture of the place. 
 It is then the favourite hiding-place and den of foxes and 
 jackals ; so that the same cavity serves at one season of the 
 year for the habitation of carnivorous beasts, and at another 
 as the channel of an engulfed river. Near the mouth of one 
 chasm, M. Boblaye and his companions saw the carcass of a 
 horse, in part devoured, the size of which seemed to have 
 prevented the jackals from dragging it in : the marks of 
 their teeth were observed on the bones, and it was evident 
 that the floods of the ensuing winter would wash in whatso- 
 ever might remain of the skeleton. 
 
 It has been stated that the waters of all these torrents 
 of the Morea are turbid where they are engulfed ; but when 
 they come out again, often at the distance of many leagues, 
 they are perfectly clear and limpid, being only charged 
 occasionally with a slight quantity of calcareous sand. The 
 points of efflux are usually near the sea-shores of the Morea, 
 bat sometimes they are submarine; and when this is the 
 case, the sands are seen to boil up for a considerable space, 
 and the surface of the sea, in calm weather, swells in large 
 convex waves. It is curious to reflect, that when this 
 discharge fails in seasons of drought, the pressure of the sea 
 may force its salt waters into subterraneous caverns, a,nd 
 carry in marine sand and shells, to be mingled with ossiferous 
 mud, and the remains of terrestrial animals. 
 
 In general, however, the efflux of water at these inferior 
 openings is constant and surprisingly uniform, seeming to 
 prove that the caverns in the interior serve as reservoirs, and 
 that the water escapes gradually from them, in consequence 
 of the smallness of the rents and passages by which they 
 communicate with the surface. 
 
 The phenomena above described are not confined to the 
 Morea, but occur in Greece generally, and in those parts of 
 
 * Bull, de la Soc. G6ol. de France, torn. iii. p. 223. 
 
CH. XLV.] ALLUVIAL DEPOSITS AND CAVES. 519 
 
 Italy, Spain, Asia Minor, and Syria, where the calcarecms 
 formations of the Morea extend. The Copaic lake in Boeotia 
 has no outlet, except by underground channels ; and hence 
 we can explain those traditional and historical accounts of 
 its having gained on the surrounding plains and overflowed 
 towns, as such floods must have happened whenever the 
 outlet was partially choked up by mud, gravel, or the sub- 
 sidence of rocks, caused by earthquakes. When speaking 
 of the numerous fissures in the limestones of Greece, M. 
 Boblaye reminds us of the famous earthquake of 469 B.C., 
 when, as we learn from Cicero, Plutarch, Strabo, and Pliny, 
 Sparta was laid in ruins, part of the summit of Mount Tay- 
 getus torn off, and numerous gulfs and fissures caused in the 
 rocks of Lacoiiia. 
 
 During the great earthquake of 1693, in Sicily, several 
 thousand people were at once entombed in the ruins of 
 caserns in limestone, at Sortino Yecchio ; and, at the same 
 time, a large stream, which had issued for ages from one of 
 the grottos below that town, changed suddenly its sub- 
 terranean course, and came out from the mouth of a cave 
 lower down the valley, where no water had previously flowed. 
 To this new point the ancient water-mills were transferred ; 
 as I learnt when I visited the spot in 1829. 
 
 When the courses of engulfed rivers are thus liable to 
 change, from time to time, by alterations in the levels of a 
 country, and by the rending and shattering of mountain 
 masses, we must suppose that the dens of wild beasts will 
 sometimes be inundated by subterranean floods, and their 
 carcasses buried under heaps of alluvium. The bones, more- 
 over, of individuals which have died in the recesses of caves, 
 or of animals which have been carried in for prey, may be 
 drifted along, and mixed up with mud, sand, and fragments 
 of rocks, so as to form osseous breccias. 
 
 In 1833 I had an opportunity of examining the celebrated 
 caves of Franconia, and among others that of Eabenstein, 
 then newly discovered. Their general form, and the nature 
 and arrangement of their contents, appeared to me to agree 
 perfectly with the notion of their having once served as the 
 channels of subterranean rivers. This mode of accounting 
 
520 BURYING OF FOSSILS IN [On. XLV. 
 
 for tlie introduction of transported matter into the Fran- 
 conian and other caves, filled up as they often are even to 
 their roofs with osseous breccia, was long ago proposed by 
 M. C. Provost,"* and seems at length to be very generally 
 adopted. But I do not doubt that bears inhabited some of 
 the German caves, or that the cavern of Kirkdale, in York- 
 shire, was once Ihe den of hysenas. The abundance of bony 
 dung, associated with hysenas' bones, has been pointed out 
 by Dr. Buckland, and with reason, as confirmatory of this 
 opinion. 
 
 The same author observed in every cave examined by him 
 in Germany, tharfc deposits of mud and sand, with or without 
 rolled pebbles and angular fragments of rock, were covered 
 over with a single crust of stalagmite. f In the English caves 
 he remarked a similar absence of alternations of alluvium and 
 stalagmite. But Dr. Schmerling has discovered in a cavern 
 at Chockier, about two leagues from Liege, three distinct 
 beds of stalagmite, and between each of them a mass of 
 breccia, and mud mixed with quartz pebbles, and in the 
 three deposits the bones of extinct quadrupeds. J 
 
 This exception does not invalidate the generality of the 
 phenomenon pointed out by Dr. Buckland, one cause of 
 which may perhaps be this, that if several floods pass at 
 different intervals of time through a subterranean passage, 
 the last, if it has power to drift along fragments of rock, 
 will also tear up any alternating stalagmitic and alluvial 
 beds that may have been previously formed. Another cause 
 may be, that a particular line of caverns will rarely be so 
 situated, in relation to the lowest levels of a country, as to 
 become, at two distinct epochs, the receptacle of engulfed 
 rivers. 
 
 As the same chasms may remain open throughout periods 
 of indefinite duration, the species inhabiting a country may 
 in the meantime be greatly changed, and thus the remains 
 of animals belonging to very different epochs may become 
 mingled together in a common tomb. 
 
 * Mem. de la Soc. d'Hist. Nat. de J Journ. de G6ol., torn. i. p. 286. 
 
 Paris, torn. iv. July, 1830. 
 
 t Keliquise Diluvianse, p. 108. 
 
CH. XLV.] ALLUVIAL DEPOSITS AND CAVES. 521 
 
 In several caverns on the banks of the Meuse, near Liege, 
 Dr. Schmerling found human bones in the same mud and 
 breccia with those of the elephant, rhinoceros, bear, and 
 other quadrupeds of extinct species. He has observed none 
 of the dung of any of these animals ; and from this circum- 
 stance, and the appearance of the mud and pebbles, he 
 concludes that these caverns were never inhabited by wild 
 beasts, but washed in by a current of water. As the human 
 skulls and bones were in fragments, and no entire skeleton 
 had been found, he does not believe that these caves were 
 places of sepulture, but that the human remains were washed 
 in at the same time as the bones of extinct quadrupeds, and 
 that these lost species of mammalia coexisted on the earth 
 with man.* 
 
 Bone-breccias formed in open fissures and caves. Among the 
 various modes in which the bones of animals become pre- 
 served independently of the agency of land floods and en- 
 gulfed rivers, I may mention that open fissures often serve as 
 natural pitfalls in which herbivorous animals perish. This 
 may happen the more readily when they are chased by 
 beasts of prey, or when surprised while carelessly browsing on 
 the shrubs which so often overgrow arid conceal the edges of 
 fissures. f 
 
 During the excavations recently made near Behat in India, 
 the bones of two deer were found at the bottom of an ancient 
 well which had been filled up with alluvial loam. Their 
 horns were broken to pieces, but the jawbones and other 
 parts of the skeleton remained tolerably perfect. ' Their 
 presence,' says Captain Cautley, c is easily accounted for, as 
 a great number of these and other animals are constantly 
 lost in galloping over the jungles and among the high grass 
 by falling into deserted wells. 5 J 
 
 Above the village of Selside, near Ingleborough in York- 
 shire, a chasm of enormous but unknown depth occurs in 
 
 * The above was written in 1834, find there a full account of the Belgian 
 
 before the coexistence of man with the caves which Ire-examined in 1860. 
 
 extinct animals had become a generally f Buckland, Keliquise Diluvianse, p. 
 
 received doctrine. In my ' Antiquity of 25. 
 
 Man,' chap. iv.,I have done more justice J See above, pp. 512, 513. 
 to Dr. Schmerling, and the reader will 
 
522 BUKYING OF FOSSILS IN [On. XLV. 
 
 the scar-limestone, a member of the carboniferous series. 
 c The chasm/ says Professor Sedgwick, c is surrounded by 
 grassy shelving banks, and many animals, tempted towards 
 its brink, have fallen down and perished in it. The approach 
 of cattle is now prevented by a strong lofty wall ; but there 
 can be no doubt that, during the last two or three thousand 
 years, great masses of bony breccia must have accumulated 
 in the lower parts of the great fissure, which probably 
 descends through the whole thickness of the scar-limestone, 
 to the depth of perhaps five or six hundred feet.' * 
 
 When any of these natural pitfalls happen to communicate 
 with lines of subterranean caverns, the bones, earth, and 
 breccia may sink by their own weight, or be washed into the 
 vaults below. 
 
 At the north extremity of the rock of Gibraltar are per- 
 pendicular fissures, on the ledges of which a number of 
 hawks nestle and rear their young in the breeding season. 
 They throw down from their nests the bones of small birds, 
 mice, and other animals on which they feed, and these are 
 gradually united into a breccia of angular fragments of the 
 decomposing limestone with a cement of red earth. 
 
 At the pass of Escrinet in France, on the northern escarp- 
 ment of the Coiron hills, near Aubenas, I have seen a breccia 
 in the act of forming. Small pieces of disintegrating lime- 
 stone are transported, during heavy rains, by a streamlet, to 
 the foot of the declivity, where landshells are very abundant. 
 The shells and pieces of stone soon become cemented together 
 by stalagmite into a compact mass, and the talus thus formed 
 is in one place 50 feet deep, and 500 yards wide. So firmly 
 is the lowest portion consolidated, that it is quarried for mill- 
 stones. 
 
 Recent stalagmitic limestone of Cuba. One of the most 
 singular examples of the recent growth of stalagmitic lime- 
 stone in caves and fissures, is that described by Mr. E,. C. 
 Taylor, as observable on the north-east part of the island of 
 Cuba.f The country there is composed of a white marble, 
 in which are numerous cavities, partially filled with a cal- 
 
 * On the Lake Mountains of North f Notes on Geol. of Cuba, 1836, 
 
 of England, Geol. Soc., Jan. 5. 1831. Phil. Mag., July, 1837. 
 
CH. XLV.] ALLUVIAL DEPOSITS AND CAVES. 523 
 
 careous deposit of a brick-red colour. In this red deposit 
 are shells, or often the hollow casts of shells, chiefly referable 
 to eight or nine species of land snails, a few scattered bones 
 of quadrupeds, and, what is still more singular, marine uni- 
 valve shells, often at the height of many hundred, or even 
 one thousand feet above the sea. The following explanation 
 is given of the gradual increase of this deposit. Land snails 
 of the genera Helix, Cyclostoma, Pupa, and Clausilia, retire 
 into the caves, the floors of which are strewed with myriads 
 of their dead and unoccupied shells, at the same time that 
 water infiltered through the mountain throws down carbonate 
 of lime, enveloping the shells, together with fragments of the 
 white limestone which occasionally falls from the roof. 
 Multitudes of bats resort to the caves ; and their dung, 
 which is of a bright red colour (probably derived from the 
 berries on which they feed), imparts its red hue to the mass. 
 Sometimes also the Hutia, or great Indian rat of the island, 
 dies and leaves its bones in the caves. ' At certain seasons 
 the soldier-crabs resort to the sea-shore, and then return 
 from their pilgrimage, each carrying with them, or rather 
 dragging, the shell of some marine univalve for many a 
 weary mile. They may be traced even at the distance of 
 eight or ten miles from the shore, on the summit of moun- 
 tains 1,200 feet high, like the pilgrims of the olden times, 
 each bearing his shell to denote the character and extent of 
 his wanderings.' By this means several species of marine 
 testacea of the genera Trochus, Turbo, Littorina, and Mono- 
 donta, are conveyed into inland caverns, and enter into the 
 composition of the newly formed rock. 
 
524 
 
 CHAPTER XLYI. 
 
 IMBEDDING OP ORGANIC REMAINS IN SUBAQUEOUS DEPOSITS. 
 
 DIVISION OF THE SUBJECT IMBEDDING OF TERRESTRIAL ANIMALS AND PLANTS 
 
 INCREASED SPECIFIC GRAVITY OF WOOD SUNK TO GREAT DEPTHS IN THE SEA 
 
 DRIFT-TIMBER CARRIED BY THE MACKENZIE INTO SLAVE LAKE AND POLAR 
 
 SEA FLOATING TREES IN THE MISSISSIPPI IN THE GULF-STREAM ON THE 
 
 COAST OF ICELAND, SPITZBERGEN, AND LABRADOR SUBMARINE FORESTS 
 
 EXAMPLES ON COAST OF HAMPSHIRE AND IN BAY OF FUNDY 
 
 MINERALISATION OF PLANTS IMBEDDING OF INSECTS OF REPTILES 
 
 BONES OF BIRDS WHY RARE IMBEDDING OF TERRESTRIAL QUADRUPEDS BY 
 
 RIVER FLOODS SKELETONS IN RECENT SHELL-MARL IMBEDDING OF MAMMI- 
 FEROUS REMAINS IN MARINE STRATA. 
 
 DIVISION OF THE SUBJECT. Having treated of the imbedding 
 of organic remains in deposits formed upon the land, I shall 
 next consider the including of the same in deposits formed 
 under water. 
 
 It will be convenient to divide this branch of our subject 
 into three parts; considering, first, the various modes 
 whereby the relics of terrestrial species may be buried in 
 subaqueous formations; secondly, the modes whereby 
 animals and plants inhabiting fresh water may be so entombed; 
 thirdly, how marine species may become preserved in new 
 strata. 
 
 The phenomena above enumerated demand a fuller share 
 of attention than those previously examined, since the depo- 
 sits which originate upon dry land are insignificant in thick- 
 ness, superficial extent, and durability, when contrasted with 
 those of subaqueous origin. At the same time, the study of 
 the latter is beset with greater difficulties ; for we are here 
 concerned with the results of processes much farther removed 
 from the sphere of ordinary observation. There is, indeed, 
 no circumstance which so seriously impedes the acquisition 
 of just views in our science as an habitual disregard of the 
 important fact, that the reproductive effects of the principal 
 
CH. XLVL] IMBEDDING OF ORGANIC REMAINS. 525 
 
 agents of change are confined to another element to that 
 larger portion of the globe, from which, by our very organi- 
 sation, we are almost entirely excluded.* 
 
 IMBEDDING OP TERRESTRIAL PLANTS. 
 
 When a tree falls into a river from the undermining of the 
 banks or from being washed in by a torrent or flood, it floats 
 on the surface, not because the woody portion is specifically 
 lighter than water, but because it is full of pores containing 
 air. When soaked for a considerable time, the water makes 
 its way into these pores, and the wood becomes water-logged 
 and sinks. The time required for this process varies in 
 different woods ; but several kinds may be drifted to great 
 distances, sometimes across the ocean, before they lose their 
 buoyancy. 
 
 If wood be sunk to vast depths in the sea, it may be im- 
 pregnated with water suddenly. Captain Scoresby informs 
 us, in his Account of the Arctic Kegions, that on one occa- 
 sion a whale, on being harpooned, ran out all the line in the 
 boat, which it then dragged under water, to the depth of 
 several thousand feet, the men having just time to escape to 
 a piece of ice. When the fish returned to the surface ( to 
 blow,' it was struck a second time, and soon afterwards killed. 
 The moment it expired it began to sink an unusual cir- 
 cumstance, which was found to be caused by the weight of 
 the sunken boat, which still remained attached to it. By 
 means of harpoons and ropes the fish was prevented from 
 sinking, until it was released from the weight by connecting 
 a rope to the lines of the attached boat, which was no sooner 
 done than the fish rose again to the surface. The sunken 
 boat was then hauled up with great labour ; for so heavy was 
 it, that although before the accident it would have been 
 buoyant when full of water, } r et it now required a boat at 
 each end to keep it from sinking. ' When it was hoisted into 
 the ship, the paint came off the wood in large sheets ; and 
 the planks, which were of wainscot, were as completely 
 soaked in every pore as if they had lain at the bottom of the 
 
 * See above, Vol. I. p. 99. 
 
526 IMBEDDING OF ORGANIC REMAINS [On. XLVI. 
 
 sea since the flood ! A wooden apparatus that accompanied 
 the boat in its progress through the deep, consisting chiefly 
 of a piece of thick deal, about fifteen inches square, happened 
 to fall overboard, and though it originally consisted of the 
 lightest fir, sank in the water like a stone. The boat was 
 rendered useless; even the wood of which it was built, on 
 being offered to the cook for fuel, was tried and rejected as 
 incombustible.'* 
 
 Captain Scoresby found that, by sinking pieces of fir, elm, 
 ash, &c. to the depth of 4,000 and sometimes 6,000 feet, 
 they became impregnated with sea- water, and when drawn 
 up again, after immersion for an hour, would no longer float. 
 The effect of this impregnation was to increase the dimen- 
 sions as well as the specific gravity of the wood, every solid 
 inch having increased one-twentieth in size and twenty-one 
 twenty-fifths in weight, f 
 
 Drift-wood of the Mackenzie River. When timber is drifted 
 down by a river, it is often arrested by lakes ; and, becoming 
 water-logged, it may sink and be imbedded in lacustrine 
 strata, if any be there forming ; sometimes a portion floats 
 on till it reaches the sea. In the course of the Mackenzie 
 Eiver in the northwestern part of North America, we have 
 an example of vast accumulations of vegetable matter now in 
 progress under both these circumstances. 
 
 In Slave Lake in particular, which is 200 miles long, the 
 quantity of drift-timber brought down annually is enormous. 
 6 As the trees,' says Dr. Richardson, ' retain their roots, 
 which are often loaded with earth and stones, they readily 
 sink, especially when water- soaked ; and accumulating in the 
 eddies, form shoals, which ultimately augment into islands. 
 A thicket of small willows covers the new-formed island as 
 soon as it appears above water, and their fibrous roots serve 
 to bind the whole firmly together. Sections of these islands 
 are annually made by the river ; and it is interesting to study 
 the diversity of appearances they present, according to their 
 different ages. The trunks of the trees gradually decay 
 until they are converted into a blackish-brown substance 
 
 * Account of the Arctic Regions, vol. ii. p. 193. f Ibid- P- 202. 
 
CH. XLVL] IN SUBAQUEOUS DEPOSITS. 527 
 
 resembling peat, but which still retains more or less of the 
 fibrous structure of the wood ; and layers of this often alter- 
 nate with layers of clay and sand, the whole being penetrated, 
 to the depth of four or five yards or more, by the long fibrous 
 roots of the willows. A deposition of this kind, with the aid 
 of a little infiltration of bituminous matter, would produce an 
 excellent imitation of coal, with vegetable impressions of the 
 willow-roots. What appeared most remarkable was the hori- 
 zontal slaty structure that the old alluvial banks presented, 
 or the regular curve that the strata assumed from unequal 
 subsidence. 
 
 ' It was in the rivers only that we could observe sections 
 of these deposits ; but the same operation goes on, on a much 
 more magnificent scale, in the lakes. A shoal of many miles 
 in extent is formed on the south side of Athabasca Lake, by 
 the drift timber and vegetable debris brought down by the 
 Elk Eiver; and the Slave Lake itself must in process of 
 time be filled up by the matters daily conveyed into it from 
 Slave River. Vast quantities of drift-timber are buried 
 under the sand at the mouth of the river, and enormous piles 
 of it are accumulated on the shores of every part of the 
 lake.'* 
 
 The banks of the Mackenzie display almost everywhere 
 horizontal beds of wood coal, alternating with bituminous 
 clay, gravel, sand, and friable sandstone ; sections, in short, 
 of such deposits as are now evidently forming at the bottom 
 of the lakes which it traverses. 
 
 Notwithstanding the vast forests intercepted by the lakes, 
 a still greater mass of drift-wood is found where the 
 Mackenzie reaches the sea, in lat. 69 N., where no wood grows 
 at present except a few stunted willows. At the mouths of 
 the river the alluvial matter has formed a barrier of islands 
 and shoals, where we may expect a great formation of coal at 
 some distant period. 
 
 The abundance of floating timber on the Mackenzie is 
 owing to the direction and to the length of the course of this 
 river, which runs from south to north, so that the sources of 
 
 * Dr. Eichardson's Geognost. Obs. on Capt. Franklin's Polar Expedition. 
 
528 IMBEDDING OF OKGANIC EEMAINS [On. XLVI. 
 
 the stream lie in much warmer latitudes than its mouths. 
 In the country, therefore, where the sources are situated, the 
 frost breaks up at an earlier season, while yet the waters in 
 the lower part of its course are ice-bound. Hence the 
 current of water, rushing down northward, reaches a point 
 where the thaw has not begun, and finding the channel of 
 the river blocked up with ice, it overflows the banks, sweeping 
 through forests of pines, and carrying away thousands of up- 
 rooted trees. 
 
 Drift-timber on coasts of Iceland, Spitzbergen, &c. Although 
 the Icelander can obtain no timber from the land, he is sup- 
 plied with it abundantly by the ocean. An immense quantity 
 of thick trunks of pines, firs, and other trees are thrown 
 upon the northern coast of the island, especially upon North 
 Cape and Cape Langaness, and are then carried by the waves 
 along these two promontories to other parts of the coast, 
 so as to afford sufficiency of wood for fuel and for construct- 
 ing boats. Timber is also carried to the shores of Labrador 
 and Greenland ; and Krantz assures us that the masses of 
 floating wood thrown by the waves upon the island of John 
 de Mayen often equal the whole of that island in extent.* 
 
 In a similar manner the bays of Spitzbergen are filled with 
 drift-wood, which accumulates also upon those parts of the 
 coast of Siberia that are exposed to the east, consisting of 
 larch, pine, Siberian cedar, fir, and other kinds of trees, 
 said to come from distant southern latitudes. Some of 
 the trunks have been deprived of their bark by friction, but 
 retain their roots and branches and are in such a state of pre- 
 servation as to form excellent building timber, f Parts of the 
 branches and almost all the roots remain fixed to the pines 
 which have been drifted into the North Sea, into latitudes 
 too cold for the growth of such timber, but the trunks are 
 usually barked. 
 
 The leaves and lighter portions of plants are seldom car- 
 ried out to sea, in any part of the globe, except during tropical 
 hurricanes among islands, and during the agitations of the 
 
 * Krantz, Hist, of Greenland, torn. i. f Olafsen, Voyage to Iceland, torn. i. 
 pp. 53-54, 
 
CH.XLVL] IN SUBAQUEOUS DEPOSITS. 529 
 
 atmosphere which sometimes accompany earthquakes and 
 volcanic eruptions. 
 
 It will appear from these observations that, although the 
 remains of terrestrial vegetation, borne down by aqueous 
 causes from the land, are chiefly deposited at the bottom of 
 lakes or at the mouths of rivers, yet a considerable quantity 
 is drifted about in all directions by currents, and may become 
 imbedded in any marine formation., or may sink down, 
 when water-logged, to the bottom of unfathomable abysses, 
 and there accumulate without intermixture of other sub- 
 stances. 
 
 It may be asked, whether we have any data for inferring 
 that the remains of a considerable proportion of the existing 
 species of plants will be permanently preserved, so as to be 
 hereafter recognisable,, supposing the strata now in progress 
 to be at some future period upraised ? To this enquiry it 
 may be answered, that there are no reasons for expecting 
 that more than a small number of the plants now flourishing 
 in the globe will become fossilised ; since the entire habita- 
 tions of a great number of them are remote from lakes and 
 seas, and even where they grow near to large bodies of water, 
 the circumstances are quite accidental and partial which 
 favour the imbedding and conservation of vegetable remains. 
 
 Submarine forest on coast of Hants. Allusion has been 
 made in the first volume, p. 544, to several localities on the 
 British shores in which the remains of trees are seen in a 
 vertical position submerged beneath the mean level of the 
 sea, often with their roots attached. In many instances it 
 seems scarcely possible to explain their submergence without 
 assuming a change to have taken place in the relative level 
 of land and sea. But such an hypothesis does not seem 
 necessary in the case about to be described. My friend, Arch- 
 deacon Harris,, discovered, in 1831, evident traces of a fir- 
 wood beneath the mean level of the sea, at Bournemouth, in 
 Hampshire, the formation having been laid open during a 
 low spring tide. It is situated between the beach and a bar 
 of sand about 200 yards off, and extends 50 yards along the 
 shore, cropping out from beneath a bed of sand and shingle. 
 It also lies in the direct line of the Bournemouth Valley, from 
 
 VOL. II. M M 
 
530 IMBEDDING OF OHGANIC REMAINS [Cn. XLVI, 
 
 the termination of which it is separated by 200 yards oi 
 shingle and drift-sand. Down the valley flows a large brook, 
 traversing near its mouth a considerable tract of rough, 
 boggy, and heathy ground, which produces a few birch trees, 
 and a great abundance of the bog- myrtle (Myrica, gale). In 
 that part of the submerged peat which was exposed at lo\\ 
 water were seen twenty or more large stumps of fir, from one 
 to two feet in height, the roots and bases of which still retair 
 their bark. The sap-wood of these is soft and spongy, but per- 
 fectly white, and exhibiting its original character. The heart- 
 wood is exceedingly hard and tough, and in the larger stumps 
 of a greenish hue like asbestos, saturated with moisture 
 and exhaling a strong odour of sulphuretted hydrogen 
 c This odour, and the greenish colour, are dependent,' says 
 Mr. Harris, ' on an incipient formation of iron pyrites, whicl 
 is proceeding with some rapidity in the peaty stratum beneath 
 The pyrites occurs in small concretions, enclosing both roots 
 and fibres. In some instances it may be seen filling up th< 
 hollow stems of grasses, in others it has penetrated to thi 
 heart of pieces of fir-wood, two or three inches in diameter 
 following the grain of the wood and often supplying its place 
 so as not to be easily perceivable till broken.' 
 
 Seventy-six rings of annual growth were counted in i 
 transverse section of one of the trees, which was fourteei 
 inches in diameter. Besides the stumps and roots of fir 
 rushes, and other compressed vegetable matter and piece 
 of alder and birch, are found in the peat. In the centr< 
 of the formation the peat was pierced two feet and a hal 
 without being passed through ; towards its edges, however 
 it is seen resting on a stratum of bluish pebbles, clay an< 
 sand, which crops out also on its seaward side, and is precisely 
 similar to the sand and pebbles that occur on the adjoining 
 heaths. The whole formation was shown to exist 40 year 
 before, in the same situation and presenting the same appear 
 ances as in 1831, and I learn from Archdeacon Harris (Feb 
 1868) that on several occasions he has since revisited the spo 
 and again observed the stumps in situ. 
 
 Now as the sea is encroaching on this shore, we may sup 
 pose that at some former period the Bournemouth Yalley ex 
 
Cu. XLVI.] IN SUBAQUEOUS DEPOSITS. 531 
 
 tended far lower, and that its extremity consisted, as at 
 present, of rough and boggy ground, partly clothed with fir- 
 trees. It is also probable that the whole of this rested on 
 the sand and pebbles already mentioned, and that the sea, in 
 its progressive encroachments, eventually laid bare, at low 
 water, the foundations of this marshy ground; in which 
 case, much of the sand constituting these foundations might 
 have been washed out by the rapid descent of the fresh water 
 through them at the fall of the tide. The superstratum of 
 vegetable matter being matted and bound together by the 
 roots of trees, would not be washed away, but might be 
 undermined, and thus sink down below the level of the sea, 
 until the waves washed sand and shingle over it. This 
 operation may have also been assisted by the occasional 
 damming up of the brook by the sand and shingle thrown up 
 during storms. Mr. Harris informs me that such an obstruc- 
 tion actually occurred in the years 1818 and 1824, and the 
 bed of the brook was completely obliterated. On these 
 occasions an artificial channel was immediately cut ; had 
 this, however, not been done, the lower part of the valley 
 would have been flooded ; and by this means the under strata 
 would have become more saturated with water, and the in- 
 creased pressure would have augmented the tendency of the 
 water to escape through them. In confirmation of this 
 hypothesis we may observe, that small streams of fresh water 
 often pass under the sands of the sea-beach, so that they 
 may be crossed dryshod, whilst the water where it issues 
 again, may be seen to carry out sand and pebbles with great 
 rapidity. 
 
 The Rev. W. B. Clarke, after examining the Bournemouth 
 submarine peat and several other similar deposits on the 
 north side of Poole Harbour, came, in 1838, to a conclusion, 
 like that adopted by Archdeacon Harris and myself, that they 
 had been sunk and submerged in modern times by the under- 
 mining of the sandy strata on which they rested, and did not 
 imply a general subsidence or change of level in that part of 
 the coast.* 
 
 * On Peat-bogs and Submarine Forests of Bourne Mouth. Rev. "W. B. Clarke, 
 Proc. of Geol. Soc., p. 599. 1838. 
 
 M si 2 
 
532 IMBEDDING OF OKGANIC EEMAINS [On. XL VI. 
 
 Submerged forest in Bay of Fundy. One of the best au- 
 thenticated examples of an old upland soil with trees, now 
 covered by about thirty feet of water at high tide, occurs 
 at Tort Lawrence in the Bay of Fundy, near the boundary 
 between Nova Scotia and New Brunswick. Dr. Dawson, an ex- 
 perienced geologist and most careful observer, has shown that 
 below layers of marine marsh-alluvium containing shells of 
 ttfanguinolaria fusca, (a bivalve shell probably identical with 
 Tellina Baltica, Linn.,) there is a bed of tough blue clay, 
 and beneath it an old peaty soil with erect trunks of trees 
 and roots. All the stumps observed were those of pine and 
 beech (Pinus strobus and Fagus ferruginea), trees indicative 
 rather of dry upland than of swampy ground. The largest 
 stump of a pine measured two and a half feet in diameter 
 and exhibited about 200 rings of annual growth. Dr. Dawson 
 counted thirty stumps in a limited area, and the same forma- 
 tion occurs at so many points as to lead him to infer that there 
 has been a very general sinking down of the land in the 
 same district. The powerful tides of the Bay of Fundy, rising 
 and falling 40 feet, cause this formation to be peculiarly well 
 exposed to view at many points, the deposit being laid bare 
 by the continual encroachments of the sea.* 
 
 Mineralisation of plants. Although the botanist and chemist 
 have as yet been unable to explain fully the manner in which 
 wood becomes petrified, it is nevertheless ascertained that, 
 under favourable circumstances, the lapidifying process is 
 now continually going on. A piece of wood was procured by 
 Mr. Stokes, from an ancient Roman aqueduct in Westphalia, 
 in which some portions were converted into spindle-shaped 
 bodies, consisting of carbonate of lime, while the rest of the 
 wood remained in a comparatively unchanged state. f It 
 appears that in some cases the most perishable, in others the 
 most durable, portions of plants are preserved, variations 
 which doubtless depend on the time when the mineral matter 
 was supplied. If introduced immediately, on the first com- 
 mencement of decomposition, then the most destructible 
 
 * Dawson, Submerged Forest at Fort t Geol. Trans., second series, vol. v. 
 
 Lawrence, Quart. Geol. Journ., vol. xi. p. 212. 
 p. 119. 1854. 
 
CH. XLVL] IX SUBAQUEOUS DEPOSITS. 533 
 
 parts are lapidified, while the more durable do not waste 
 away till afterwards, when the supply has failed, and so never 
 become petrified. The converse of these circumstances gives 
 rise to exactly opposite results. 
 
 Professor Goppert, of Breslau, has instituted a series of 
 curious experiments, in which he has succeeded in producing 
 some very remarkable imitations of fossil petrifactions. He 
 placed recent ferns between soft layers of clay, dried these in 
 the shade, and then slowly and gradually heated them, till 
 the clay was red-hot. The result was the production of so 
 perfect a counterpart of fossil plants as might have deceived 
 an experienced geologist. According to the different degrees 
 of heat applied, the plants were obtained in a brown or per- 
 fectly carbonised condition ; and sometimes, but more rarely, 
 they were in a black shining state, adhering closely to the 
 layer of clay. If the red heat was sustained until all the 
 organic matter was burnt up, only an impression of the plant 
 remained. 
 
 The same chemist steeped plants in a moderately strong 
 solution of sulphate of iron, and left them immersed in it for 
 several days, until they were thoroughly soaked in the liquid. 
 They were then dried, and kept heated until they would no 
 longer shrink in volume, and until every trace of organic 
 matter had disappeared. On cooling them he found that the 
 oxide formed by this process had taken the form of the plants. 
 A variety of other experiments were made by steeping animal 
 and vegetable substances in siliceous, calcareous, and metallic 
 solutions, and all tended to prove that the mineralisation of 
 organic bodies can be carried much farther in a short time 
 than had been previously supposed.* 
 
 Imbedding of insects. I have observed the elytra and other 
 parts of beetles in a band of fissile clay, separating two beds 
 of recent shell-marl, in the Loch of Kinnordy in Forfarshire. 
 Amongst these, Mr. Curtis recognised Elator lineatus and 
 Atopa cervina, species still living in Scotland. These, as well 
 as other remains which accompanied them, appear to belong 
 to terrestrial, not aquatic, species, and must have been 
 
 * G-oppert, Poggendorff s Annalen part iv., Leipsic, 1836. See also Lyell's 
 ier Physik und Chemie, vol. xxxviii. Manual of Creol., p. 49. 
 
534 IMBEDDING OF ORGANIC REMAINS [Cn. XL VI. 
 
 carried down in muddy water during an inundation. In the 
 lacustrine peat of the same locality, the elytra of beetles are 
 not uncommon ; but in the deposits of drained lakes gener- 
 ally, and in the silt of our estuaries, the relics of this class 
 of the animal kingdom are rare. In the blue clay of very 
 modern origin of Lewes levels, Dr. Mantell has found the 
 Indusia, or cases of the larvse of Phryganea, in abundance, 
 with minute shells belonging to the genera Planorbis, 
 Limnea, &c., adhering to them.* 
 
 When speaking of the migrations of insects, I pointed out 
 that an immense number are floated into lakes and seas by 
 rivers, or blown by winds far from the land ; but they are so 
 buoyant that we can only suppose them, under very peculiar 
 circumstances, to sink to the bottom before they are either 
 devoured by insectivorous animals or decomposed. 
 
 Of land and freshwater reptiles. As the bodies of several 
 crocodiles were found in the mud brought down to the sea 
 by the river inundation which attended an earthquake in 
 Java, in the year 1699, we may imagine that extraordinary 
 floods of mud may stifle many individuals of the shoals of 
 alligators and other reptiles which frequent lakes and the 
 deltas of rivers in tropical climates. Thousands of frogs 
 were found leaping about among the wreck, carried into the 
 sea by the inundations in Moray shire, in 1829 ;f and it is 
 evident that whenever a sea-cliff is undermined, or land is 
 swept by other violent causes into the sea, land reptiles may 
 be carried in. 
 
 Of birds. We might have anticipated that the imbedding 
 of the remains of birds in new strata would be of very rare 
 occurrence, for their powers of flight insure them against 
 perishing by numerous casualties to which quadrupeds are 
 exposed during floods ; and if they chance to be drowned, or 
 to die when swimming on the water, it will scarcely ever 
 happen that they will be submerged so as to become preserved 
 in sedimentary deposits. In consequence of the hollow 
 tubular structure of their bones and the quantity of their 
 feathers they are extremely light in proportion to their 
 
 * Trans. Geol. Soc., vol. iii. part i. f Sir T. D. Lauder's Account, 2nd ed., 
 
 p. 201, second series. p. 312. 
 
 
CH. XLVI.] IN SUBAQUEOUS DEPOSITS. :>:;."> 
 
 volume ; so that when first killed they do not sink to the 
 bottom like quadrupeds, but float on the surface until the 
 carcass either rots away or is devoured by predaceous animals. 
 To these causes we may ascribe the absence of any vestige 
 of the bones of birds in the recent marl formations of Scotland ; 
 although these lakes, until the moment when they were artifi- 
 cially drained, were frequented by a great abundance of water- 
 fowl. 
 
 IMBEDDING OF TERRESTRIAL QUADRUPEDS. 
 
 Eiver inundations recur in most climates at very irregular 
 intervals, and expend their fury on those rich alluvial plains, 
 where herds of herbivorous quadrupeds congregate together. 
 These animals are often surprised ; and, being unable to stem 
 the current, are hurried along until they are drowned, when 
 they sink at first immediately to* the bottom. Here their 
 bodies are drifted along, together with sediment, into lakes or 
 seas, and may then be covered by a mass of mud, sand, and 
 pebbles, thrown down upon them. If there be no sediment 
 superimposed, the gases generated by putrefaction usually 
 cause the bodies to rise again to the surface about the ninth or 
 at latest the fourteenth day. The pressure of a thin covering 
 of mud would not be sufficient to retain them at the bottom ; 
 for we see the putrid carcasses of dogs and cats, even in rivers, 
 floating with considerable weights attached to them, and in 
 sea- water they would be still more buoyant. 
 
 Where the body is so buried in drift- sand, or mud accumu- 
 lated upon it, as never to rise again, the skeleton may be 
 preserved entire ; but if it comes again to the surface while 
 in the process *of putrefaction, the bones commonly fall 
 piecemeal from the floating carcass, and may in that case be 
 scattered at random over the bottom of the lake, estuary, or 
 sea ; so that a jaw may afterwards be found in one place, a 
 rib in another, a humerus in a third all included, perhaps, 
 in a matrix of fine materials, where there may be evidence 
 of very slight transporting power in the current, or even of 
 none, but simply of some chemical precipitate. 
 
 A large number of the bodies of drowned animals, if they 
 float into the sea or a lake, especially in hot climates, are 
 
536 IMBEDDING OF OKG-ANIC KEMAINS [Cn. XL VI. 
 
 instantly devoured by sharks, alligators, and other carnivo- 
 rous beasts, which may have power to digest even the bones ; 
 but during extraordinary floods, when the greatest number 
 of land animals are destroyed, the waters are commonly so 
 turbid, especially at the bottom of the channel, that even 
 aquatic species are compelled to escape into some retreat 
 where there is clearer water lest they should be stifled. For 
 this reason, as well as the rapidity of sedimentary deposition 
 at such seasons, the probability of carcasses becoming per- 
 manently imbedded is considerable. 
 
 In recent shell-marl, Scotland. In some instances, the 
 skeletons of quadrupeds are met with abundantly in recent 
 shell-marls in Scotland, where we cannot suppose them to 
 have been imbedded by the action of rivers or floods. They 
 all belong to species which now inhabit, or are known to 
 have been indigenous in Scotland. The remains of several 
 hundred skeletons have been procured within the last century 
 from five or six small lakes in Forfarshire, where shell-marl 
 has been worked. Those of the stag (Cervus Elaphus) are 
 most numerous ; and if the others be arranged in the order 
 of their relative abundance, they will follow nearly thus 
 the ox, the boar, the horse, the sheep, the dog, the hare, the 
 fox, the wolf, and the cat. The beaver seems extremely rare ; 
 but it has been found in the shell-marl of Loch Marlie, in 
 Perthshire, and in the parish of Edrom, in Berwickshire. 
 
 In the greater part of these lake-deposits there are no 
 signs of floods ; and the expanse of water was originally so 
 confined, that the smallest of the above-mentioned quadrupeds 
 could have crossed, by swimming from one shore to the 
 other. Deer, and such species as take readily to the water, 
 may often have been mired in trying to land, where the 
 bottom was soft and quaggy, and in their efforts to escape 
 may have plunged deeper into the marly bottom. But many 
 individuals, I suspect, of different species, have fallen in 
 when crossing the frozen surface in winter ; for nothing can 
 be more treacherous than the ice when covered with snow, 
 in consequence of the springs, which are numerous, and 
 which, retaining always an equal temperature, cause the ice, 
 in certain spots, to be extremely thin, while in every other 
 
Cn. XL VI.] IN SUBAQUEOUS DEPOSITS. 537 
 
 part of the lake it is strong enough to bear the heaviest 
 weights. 
 
 Flood in the Solway Firth, 1 794. One of the most memor- 
 able floods of modern date, in our island, is that which 
 visited part of the southern borders of Scotland, on the 24th 
 of January, 1794, and which spread particular devastation 
 over the country adjoining the Solway Firth. 
 
 We learn from the account of Captain Napier, that the 
 heavy rains had swollen every stream which entered the 
 Firth of Solway; so that the inundation not only carried 
 away a great number of cattle and sheep, but many of the 
 herdsmen and shepherds, washing down their bodies into the 
 estuary. After the storm, when the flood subsided, an extra- 
 ordinary spectacle was seen on a large sand-bank called f the 
 beds of Esk,' where there is a meeting of the tidal waters, 
 and where heavy bodies are usually left stranded after great 
 floods. On this single bank were found collected together 
 the bodies of 9 black cattle, 3 horses, 1,840 sheep, 45 dogs, 
 180 hares, besides a great number of smaller animals, and, 
 mingled with the rest, the corpses of two men and one 
 woman.* 
 
 Floods in Scotland, 1829. In those more recent floods in 
 Scotland, in August, 1829, whereby a fertile district on the 
 east coast became a scene of dreadful desolation, a vast 
 number of animals and plants were washed from the land, 
 and found scattered about after the storm, around the mouths 
 of the principal rivers. An eye-witness thus describes the 
 scene which presented itself at the mouth of the Spey, in 
 Morayshire : ' For several miles along the beach crowds 
 were employed in endeavouring to save the wood and other 
 wreck with which the heavy-rolling tide was loaded ; whilst 
 the margin of the sea was strewed with the carcasses of 
 domestic animals, and with millions of dead hares and 
 rabbits. 'f 
 
 Savannahs of South America. We are informed by Hum- 
 boldt, that during the periodical swellings of the large rivers 
 in South America great numbers of quadrupeds are annually 
 
 * Treatise on Practical Store Farm- Morayshire, 1829; and above, Vol. I. 
 ing, p. 25. p. 349. 
 
 f Sir T. D. Lander's Floods in 
 
538 IMBEDDING OF OKGANIC KEMAINS [On. XL VI. 
 
 drowned. Of the wild horses, for example, which graze in 
 immense troops in the savannahs, or level grassy plains, 
 thousands are said to perish when the river Apure, a tributary 
 of the Orinoco, is swollen, before they have time to reach the 
 rising ground of the Llanos. The mares, during the season 
 of high water, may be seen, followed by their colts, swimming 
 about and feeding on the grass, of which the top alone waves 
 above the waters. In this state they are pursued by croco- 
 diles ; and their thighs frequently bear the prints of the 
 teeth of these carnivorous reptiles. c Such is the pliability,' 
 observes the celebrated traveller, ' of the organisation of the 
 animals which man has subjected to his sway, that horses, 
 cows, and other species of European origin, lead, for a time, 
 an amphibious life, surrounded by crocodiles, water-serpents, 
 and manatees. When the rivers return again into their beds, 
 they roam in the savannah, which is then spread over with a 
 fine odoriferous grass, and enjoy, as in their native climate, 
 the renewed vegetation of spring. 3 * 
 
 Floods of the Parana. The great number of animals which 
 are drowned in seasons of drought in the tributaries of the 
 Plata, was before mentioned. Sir W. Parish states, that the 
 Parana flowing from the mountains of Brazil to the estuary 
 of the Plata, is liable to great floods, and during one of these, 
 in the year 1812, vast quantities of cattle were carried away, 
 'and when the waters began to subside, and the islands 
 which they had covered became again visible, the whole 
 atmosphere for a time was poisoned by the effluvia from the 
 innumerable carcasses of skunks, capybaras, tigers, and other 
 wild beasts which had been drowned. 'f 
 
 Floods of the Ganges. We find it continually stated, by 
 those who describe the Ganges and Burrampooter, that these 
 rivers carry before them, during the flood season, not only 
 floats of reeds and timber, but dead bodies of men, deer, and 
 
 oxen.J 
 
 Java, 1699. I have already referred to the effects of a 
 flood which attended an earthquake in Java in 1699, when 
 the turbid waters of the Batavian river destroyed all the 
 
 * Humboldt's Pers. Nar., vol. iv. t Buenos Ayres and La Plata, p. 187. 
 
 p. 394. | Malte-Bmn, Geog., vol. iii. p. 22. 
 
CH. XLVL] IN SUBAQUEOUS DEPOSITS. f>o!) 
 
 fish except the carp ; and when drowned buffaloes, tigers, 
 rhinoceroses, deer, apes, and other wild beasts, were brought 
 down to the sea-coast by the current, with several crocodiles 
 which had been stifled in the mud. (See above, p. 159.) 
 
 On the western side of the same island, in the territory of 
 Galongoon, in the Kegencies, a more recent volcanic eruption 
 (that of 1822, before described see above, p. 57), was attended 
 by a flood, during which the river Tandoibore down hundreds 
 of carcasses of rhinoceroses and buifaloes, and swept away 
 more than 100 men and women from a multitude assembled 
 on its banks to celebrate a festival. Whether the bodies 
 reached the sea, or were deposited, with drift matter, in some 
 of the large intervening alluvial plains, we are not in- 
 formed.* 
 
 Sumatra. ' On the coast of Orissa,' says Heynes, ' I have 
 seen tigers and whole herds of black cattle carried along by 
 what are called freshes, and trees of immense size.'f 
 
 Virginia, 1771. I might enumerate a great number of 
 local deluges that have swept through the fertile lands 
 bordering on large rivers, especially in tropical countries, 
 but I should surpass the limits assigned to this work. I 
 may observe, however, that the destruction of the islands, 
 in rivers, is often attended with great loss of life. Thus 
 when the principal river in Virginia rose in 1771, to the 
 height of 25 feet above its ordinary level, it swept entirely 
 away Elk Island, on which were 700 head of quadru- 
 peds, horses, oxen, sheep, and hogs, and nearly 100 
 houses. J 
 
 The reader will gather, from what was before said re- 
 specting the deposition of sediment by aqueous causes, that 
 .the greater number of the remains of quadrupeds drifted 
 away by rivers must be intercepted by lakes before they 
 reach the sea, or buried in freshwater formations near the 
 mouths of rivers. If they are carried still farther, the pro- 
 babilities are increased of their rising to the surface in a 
 state of putrefaction, and, in that case, of being there devoured 
 
 * This accountl had from Mr. Baum- f Tracts on India, p. 397. 
 
 hauer, Director-General of Finances in \ Scots Mag., vol. xxxiii. 
 
 Java. 
 
540 IMBEDDING OF OKGANIC KEMAINS. [On. XL VI. 
 
 by aquatic beasts of prey, or of subsiding into some spots 
 whither no sediment is conveyed, and, consequently, where 
 every vestige of them will, in the course of time, disappear. 
 
 Mammiferous remains in marine strata. As the bones of 
 mammalia are often so abundantly preserved in peat, and 
 such lakes as have just been described, the encroachments of 
 the sea upon a coast must sometimes throw down the imbedded 
 skeletons, so that they may be carried away by tides and 
 currents, and entombed in submarine formations. Some of 
 the smaller quadrupeds, also, which burrow in the ground, 
 as well as reptiles and every species of plant, are liable to be 
 cast down into the waves by this cause, which must not be 
 overlooked, although probably of comparatively small im- 
 portance amongst the numerous agents whereby terrestrial 
 organic remains are included in submarine strata. 
 
 During the great earthquake of Conception in 1835, some 
 cattle, which were standing on the steep sides of the island 
 of Quiriquina, were rolled by the shock into the sea, while 
 on a low island at the head of the Bay of Conception seventy 
 animals were washed off by a great wave and drowned.* 
 
 * Darwin's Journal, p. 372, 2nd ed. 1845. p. 304. 
 
541 
 
 CHAPTER XL VII. 
 
 IMBEDDING OF THE REMAINS OF MAN AND HIS WORKS IN 
 SUBAQUEOUS STRATA. 
 
 DRIFTING OF HUMAN BODIES TO THE SEA BY RIVEE INUNDATIONS HOW HUMAN 
 
 CORPSES MAY BE PRESERVED IN RECENT DEPOSITS FOSSIL SKELETONS OF MEN 
 
 NUMBER OF WRECKED VESSELS FOSSIL CANOES, SHIPS, AND WORKS OF ART 
 
 CHEMICAL CHANGES WHICH METALLIC ARTICLES HAVE UNDERGONE AFPER 
 
 LONG SUBMERGENCE IMBEDDING OF CITIES AND FORESTS IN SUBAQUEOUS 
 
 STRATA BY SUBSIDENCE EARTHQUAKE OF CUTCH IN 1819 BURIED TEMPLES 
 
 OF CASHMERE BERKELEY'S ARGUMENTS FOR THE RECENT DATE OF THE CREA- 
 TION OF MAN MONUMENTS OF PRE-HISTORIC MAN DISCOVERED IN POST-TERTI- 
 ARY STRATA. 
 
 I SHALL now proceed to enquire in what manner the mortal 
 remains of man and the works of his hands may be per- 
 manently preserved in subaqueous strata. Of the many 
 hundred million human beings which perish in the course of 
 every century on the land, every vestige is usually destroyed 
 in the course of a few thousand years ; but of the smaller 
 number that perish in the waters, a certain proportion must 
 be entombed under circumstances that may enable parts of 
 them to endure throughout entire geological epochs. 
 
 The bodies of men, together with those of the inferior 
 animals, are occasionally washed down during river inunda- 
 tions into seas and lakes. Belzoni witnessed a flood on the 
 Nile in September, 1818, where, although the river rose 
 only three feet and a half above its ordinary level, several 
 villages, with some hundreds of men, women, and children, 
 were swept away.* It was before mentioned that a rise of 
 six feet of water in the Ganges, in 1763, was attended with 
 a much greater loss of life. (See above, Yol. I. p. 474.) 
 
 In the year 1771, when the inundations in the north of 
 
 * Narrative of Discovery in Egypt, &c., London, 1820. 
 
542 IMBEDDING OF THE BEMAINS OF MAN AND [On. XLVII. 
 
 England appear to have equalled the floods of Morayshire 
 in 1829, a great number of houses and their inhabitants were 
 swept away by the rivers Tyne, Can, Wear, Tees, and Greta ; 
 and no less than twenty-one bridges were destroyed in the 
 courses of these rivers. At the village of Bywell the flood 
 tore the dead bodies and coffins out of the churchyard, and 
 bore them away, together with many of the living inhabit- 
 ants. During the same tempest an immense number of cattle, 
 horses, and sheep were also transported to the sea, while the 
 whole coast was covered with the wreck of ships. Four cen- 
 turies before (in 1338), the same district had been visited by 
 a similar continuance of heavy rains followed by disastrous 
 floods, and it is not improbable that these catastrophes 
 may recur periodically, though after uncertain intervals. 
 As the population increases, and buildings and bridges are 
 multiplied, we must expect the loss of lives and property to 
 augment.* 
 
 Preservation of human bodies in the bed of the sea. If to 
 the hundreds of human bodies committed to the deep in the 
 way of ordinary burial we add those of individuals lost by 
 shipwrecks, we shall find that, in the course of a single 
 year, a great number of human remains are consigned to 
 the subaqueous regions. I shall hereafter advert to a calcu- 
 lation by which it appears that more than 500 British vessels 
 alone, averaging each a burden of about 120 tons, were 
 wrecked, and sunk to the bottom, annually between the 
 years 1793 and 1829. Of these the crews for the most part 
 escape, although it sometimes happens that all perish. In one 
 great naval action several thousand individuals sometimes 
 share a watery grave. 
 
 Many of these corpses are instantly devoured by predaceous 
 fish, sometimes before they reach the bottom ; still more 
 frequently when they rise again to the surface, and float in a 
 state of putrefaction. Many decompose on the floor of the 
 ocean, where no sediment is thrown down upon them ; but 
 if they fall upon a reef where corals and shells are becoming 
 agglutinated into a solid rock, or subside where the delta of 
 
 * Scots Mag. vol. xxxiii. 1771. 
 
Cii. XLVIL] HIS WORKS IN SUBAQUEOUS STRATA. 543 
 
 a river is advancing, they may be preserved for an incalcu- 
 lable series of ages. 
 
 Often at the distance of a few hundred feet from a coral 
 reef, where wrecks are often not unfrequent, there are no 
 soundings at the depth of many hundred fathoms. Canoes, 
 merchant vessels, and ships of war may have sunk and have 
 been enveloped, in such situations, in calcareous sand and 
 breccia, detached by the breakers from the summit of a 
 submarine mountain. Should a volcanic eruption happen 
 to cover such remains with ashes and sand, and a current of 
 lava be afterwards poured over them, the ships and human 
 skeletons might remain uninjured between the superincum- 
 bent mass, like the houses and works of art in the sub- 
 terranean cities of Campania. Already many human remains 
 may have been thus preserved beneath formations more than 
 1,000 feet in thickness ; for, in some volcanic archipelagos, 
 a period of thirty or forty centuries might well be supposed 
 sufficient for such an accumulation. It was stated, that at 
 the distance of about 40 miles from the base of the delta of 
 the Ganges, there is an elliptical space about 15 miles 'in 
 diameter where soundings of from 100 to 300 fathoms 
 sometimes fail to reach the bottom. (See above, Vol. I. 
 p. 475.) As during the flood season the quantity of mud 
 and sand poured by the great rivers into the Bay of Bengal 
 is so great that the sea only recovers its transparency at the 
 distance of 60 miles from the coast, this depression must be 
 gradually shoaling, especially as during the monsoons, the 
 sea, loaded with mud and sand, is beaten back in that 
 direction towards the delta. If therefore a ship or human 
 body sink down to the bottom in such a spot, it will probably 
 soon become buried under sediment. 
 
 Even on that part of the floor of the ocean to which no 
 accession of drift matter is carried (a part which probably 
 constitutes, at any given period, by far the larger proportion 
 of the whole submarine area), there are circumstances 
 accompanying a wreck which favour the conservation of 
 skeletons. For when the vessel fills suddenly with water, 
 especially in the night, many persons are drowned between 
 decks and in their cabins, so that their bodies are prevented 
 
541 IMBEDDING OF THE KEMAINS OF MAN AND [Cn. XL VII. 
 
 .from rising again to the surface. The vessel often strikes 
 upon an uneven bottom, and is overturned ; in which case 
 the ballast, consisting of sand, shingle, and rock, or the 
 cargo, frequently composed of heavy and durable materials, 
 may be thrown down upon the carcasses. In the case of 
 ships of war, cannon, shot, and other warlike stores, may 
 press down with their weight the timbers of the vessel as 
 they decay, and beneath these and the metallic substances 
 the bones of man may be preserved. 
 
 Power of human remains to resist decay. There can be no 
 doubt that human remains are as capable of resisting decay 
 as are the harder parts of the inferior animals ; and I have 
 already cited the remark of Cuvier, that c in ancient fields of 
 battle the bones of men have suffered as little decomposition 
 as those of horses which were buried in the same grave.' 
 (See above, Vol. I. p. 166.) In the delta of the Ganges bones 
 of men have been found in digging a well at the depth of 90 
 feet ; * but as that river frequently shifts its course and fills 
 up its ancient channels, we are not called upon to suppose 
 that these bodies are of extremely high antiquity, or that 
 they were buried when that part of the surrounding delta 
 where they occur was first gained from the sea. 
 
 Several skeletons of men, more or less mutilated, have 
 been found in the West Indies, on the northwest coast of 
 the main land of Guadaloupe, in a kind of rock which is 
 known to be forming daily, and which consists of minute 
 fragments of shells and corals, incrusted with a calcareous 
 cement resembling travertin, by which also the different 
 grains are bound together. The lens shows that some of the 
 fragments of coral composing this stone still retain the same 
 red colour which is seen in the reefs of living coral which 
 surround the island. The shells belong to species of the 
 neighbouring sea intermixed with some terrestrial kinds 
 which now live on the island, and among them is the 
 Bulimus Guadaloupensis of Ferussac. The human skeletons 
 still retain some of their animal matter, and all their phos- 
 phate of lime. One of them, of which the head is wanting, 
 
 * Von Hoff, vol. i. p. 379. 
 
CH. XLVIL] HIS WORKS IN SUBAQUEOUS STRATA. 545 
 
 may now be seen in the British Museum, and another in the 
 Royal Cabinet at Paris. According to M. Konig, the rock in 
 which the former is enclosed is harder under the mason's saw 
 and chisel than statuary marble. It is described as forming 
 a kind of glacis, probably an indurated beach, which slants 
 from the steep cliffs of the island to the sea, and is nearly 
 all submerged at high tide. 
 
 Number of wrecked vessels. When we reflect on the number 
 of curious monuments consigned to the bed of the ocean 
 in the course of every naval war from the earliest times, our 
 conceptions are greatly raised respecting the multiplicity of 
 lasting memorials which man is leaving of his labours. 
 During our last great struggle with France, thirty-two of 
 our ships of the line went to the bottom in the space of 
 twenty-two years, besides seven 50-gun ships, eighty-six 
 frigates, and a multitude of smaller vessels. The navies of 
 the other European powers, France, Holland, Spain, and 
 Denmark, were almost annihilated during the same period, 
 so that the aggregate of their losses must have many times 
 exceeded that of Great Britain. In every one of these ships 
 were batteries of cannon constructed of iron or brass, whereof 
 a great number had the dates and places of their manu- 
 facture inscribed upon them in letters cast in metal. In 
 each there were coins of copper, silver, and often many 
 of gold, capable of serving as valuable historical monu- 
 ments ; in each were an infinite variety of instruments of 
 the arts of war and peace ; many formed of materials, such 
 as glass and earthenware, capable of lasting for indefinite 
 ages when once removed from the mechanical action of the 
 waves, and buried under a mass of matter which may exclude 
 the corroding action of sea-water. The quantity, moreover, 
 of timber which is conveyed from the land to the bed of the 
 sea by the sinking of ships of a large size is enormous ; for 
 it is computed that 2,000 tons of wood are required for the 
 building of one 74-gun ship; and reckoning fifty oaks of 
 100 years' growth to the acre, it would require forty acres of 
 oak forest to build one of these vessels.* 
 
 * Quart, Journ. of Agricult, No. ix. p. 433. 
 VOL. II. N N 
 
546 IMBEDDING OF THE EEMAINS OF MAN AND [Cn. XL VII. 
 
 It would be an error to imagine that the fury of war is 
 more conducive than the peaceful spirit of commercial enter- 
 prise to the accumulation of wrecked vessels in the bed of 
 the sea. From an examination of Lloyd's lists, from the 
 year 1793 to the commencement of 1829, the late Admiral 
 Smyth ascertained that the number of British vessels alone 
 lost during that period amounted on an average to no less 
 than one and a half daily ; an extent of loss which would 
 hardly have been anticipated, although we learn from Mo- 
 reau's tables that the number of merchant vessels employed 
 at that time, in the navigation of England and Scotland, 
 amounted to about 20,000, having one with another a mean 
 burden of 120 tons.* According to Lloyd's list for the 
 years 1820, 1830, and 1831, no less than 1,953 vessels were 
 lost in those three years, their average tonnage being about 
 150 tons, or in all nearly 300,000 tons, being at the enormous 
 rate of 100,000 tons annually of the merchant vessels of one 
 nation only. 
 
 Out of 551 ships of the royal navy lost to the country 
 during the period above mentioned, only 160 were taken or 
 destroyed by the enemy, the rest having either stranded or 
 foundered, or having been burnt by accident: a striking 
 proof that the dangers of our naval warfare, however great, 
 may be far exceeded by the storm, the shoal, the lee-shore, 
 and all the other perils of the deep.f 
 
 In the wreck register for 1866, published by the Board of 
 Trade, the number of shipwrecks and other casualties at sea 
 is stated at no less than 1,860 on the coast of the United 
 Kingdom and in the adjacent seas, and the number of 
 persons drowned as 896, showing how greatly the loss 
 increases from increasing activity in commerce. 
 
 Buried ships, canoes, and works of art. When a vessel is 
 stranded in shallow water, it usually becomes the nucleus of a 
 sandbank, as has been exemplified in several of our harbours, 
 and this circumstance tends greatly to its preservation. 
 Between the years 1780 and 1790 a vessel from Purbeck, 
 laden with 300 tons of stone, struck on a shoal off the 
 
 * Caesar Moreau's Tables of the Na- f I give these results on the author- 
 
 vigation of Great Britain. ity of the late Admiral Smyth, E. N. 
 
CH. XLVIL] HIS WORKS IN SUBAQUEOUS STRATA. 547 
 
 entrance of Poole harbour and foundered ; the crew were 
 saved, but the vessel and cargo remain to this day at the 
 bottom. Since that period the shoal at the entrance of the 
 harbour has so extended itself in a westerly direction towards 
 Peveril Point in Purbeck, that the navigable channel is thrown 
 a mile nearer that point.* The cause is obvious : the tidal 
 current deposits the sediment with which it is charged around 
 any object which checks its velocity. Matter also drifted 
 along the bottom is arrested by any obstacle, and accumulates 
 round it, just as the African sand-winds, before described, 
 raise a small hillock over the carcass of every dead camel 
 exposed on the surface of the desert. 
 
 I before alluded to an ancient Dutch vessel, discovered in 
 the deserted channel of the river Rother, in Sussex, of which 
 the oak wood was much blackened, but its texture unchanged. 
 (See above, Yol. I. p. 528.) The interior was filled with fluvia- 
 tile silt, as was also the case in regard to a vessel discovered 
 in a former bed of the Mersey, and another disinterred where 
 the Sfc. Katherine Docks are excavated in the alluvial plain 
 of the Thames. In like manner many ships have been found 
 preserved entire in modern strata, formed by the silting up of 
 estuaries along the southern shores of the Baltic, especially 
 in Pomerania. Between Bromberg and Nakel, for example, 
 a vessel and two anchors in a very perfect state were dug up 
 ar from the sea.f 
 
 Several vessels have been lately detected half buried in the 
 lelta of the Indus, in the numerous deserted branches of that 
 iver, far from where the stream now flows. One of these, 
 bund near Yikkar in Sinde, was 400 tons in burden, old- 
 ashioned, and pierced for fourteen guns, and in a region 
 here it had been matter of dispute whether the Indus had 
 sver been navigable by large vessels. J 
 
 At the mouth of a river in Nova Scotia, a schooner of 
 52 tons, laden with live stock, was lying with her side to 
 tide, when the bore, or tidal wave, which rises there 
 ibout 10 feet in perpendicular height, rushed into the estuary, 
 
 * This account I received from the { Lieut. Carless, Geograph. Journ., 
 
 lonourable and Yen. Chas. Harris. vol. viii. p. 338. 
 
 t Von Hoff, vol. i. p. 368. 
 
 N j? 2 
 
548 IMBEDDING OF THE REMAINS OF MAN AND [On. XLVII. 
 
 and overturned the vessel, so that it instantly disappeared. 
 After the tide had ebbed, the schooner was so totally buried 
 in the sand, that the taffrel or upper rail over the stern was 
 alone visible.* We are informed by Leigh that, on drain- 
 ing Martin Mere, a lake eighteen miles in circumference, in 
 Lancashire, a bed of marl was laid dry, wherein no fewer 
 than eight canoes were found imbedded. In figure and 
 dimensions they were not unlike those now used in America. 
 In a morass about nine miles distant from this mere a whet- 
 stone and an axe of mixed metal were dug up.f In Ayrshire 
 also, three canoes were found in Loch Doon early in the 
 present century ; and during the year 1831 four others, each 
 hewn out of separate oak trees. They were 23 feet in length, 
 2^ in depth, and nearly 4 feet in breadth at the stern. In 
 the mud which filled one of them was found a war-club of 
 oak and a stone battle-axe. A canoe of oak was also found 
 in 1820, in peat overlying the shell-marl of the Loch of Kin- 
 nordy in Forfar shire. J 
 
 Manner in which ships may be preserved in a deep sea. It is 
 extremely possible that the submerged woodwork of ships 
 which have sunk where the sea is two or three miles deep has 
 undergone greater chemical changes in an equal space of 
 time than in the cases above mentioned ; for the experiments 
 of Scoresby show that wood may at certain depths be impreg- 
 nated in a single hour with salt water, so that its specific 
 gravity is entirely altered, (See above, p. 525.) It may often 
 happen that springs charged with carbonate of lime, silex, 
 and other mineral ingredients, may issue at great depths, in 
 which case every pore of the vegetable tissue may be injected 
 with the lapidifying liquid, whether calcareous or siliceous, 
 before the smallest decay commences. The conversion, also, 
 of wood into lignite is probably more rapid under enormous 
 pressure. But the change of the timber into lignite or coal 
 would not prevent the original form of a ship from being dis- 
 tinguished ; for as we find, in strata of the carboniferous era, 
 
 * Silliman's Geol. Lectures, p. 78, J Geol. Trans., second series, vol. ii. 
 
 who cites Penn. p. 87. For buried canoes near Glasgow 
 
 t Leigh's Lancashire, p. 17, A. D. see ' Antiquity of Man,' p. 48. 
 1700. 
 
Cn. XL VII.] HIS WORKS IN SUBAQUEOUS STRATA. 549 
 
 the bark of the hollow reed-like trees converted into coal, and 
 the central cavity filled with sandstone, so might we trace 
 the outline of a ship in coal ; while in the indurated mud, 
 sandstone, or limestone, filling the interior, we might dis- 
 cover instruments of human art, ballast consisting of rocks 
 foreign to the rest of. the stratum, and other contents of the 
 ship. 
 
 Submerged metallic substances. Many of the metallic sub- 
 stances which fall into the waters probably lose, in the course 
 of ages, the forms artificially imparted to them ; but under 
 certain circumstances these may be preserved for indefinite 
 periods. The cannon enclosed in a calcareous rock, drawn 
 up from the delta of the Rhone, which is now in the museum 
 at Montpellier, might probably have endured as long as the 
 calcareous matrix ; but even if the metallic matter had been 
 removed, and had entered into new combinations, still a 
 mould of its original shape would have been left, correspond- 
 ing to those impressions of shells which we see in rocks, from 
 which all the carbonate of lime has been subtracted. About 
 the year 1776, says Mr. King, some fishermen, sweeping for 
 anchors in the Gulf-stream (a part of the sea near the Downs), 
 drew up a very curious old swivel gun, nearly eight feet in 
 length. The barrel, which was about five feet long, was of 
 brass ; but the handle by which it was traversed was about 
 three feet in length, and the swivel and pivot on which it 
 turned were of iron. Around these latter were formed in- 
 crustations of sand converted into a kind of stone, of ex- 
 ceedingly strong texture and firmness ; whereas round the 
 barrel of the gun, except where it was near adjoining to the 
 iron, there were no such incrustations, the greater part of 
 it being clean, and in good condition, just as if it had still 
 continued in use. In the incrusting stone, adhering fco it on 
 the outside, were a number of shells and corallines, ' just as 
 they are often found in a fossil state.' These were all so 
 strongly attached, that it required as much force to separate 
 them from the matrix c as to break a fragment off any hard 
 rock.'* 
 
 In the year 1745, continues the same writer, the Fox man- 
 
 * Phil. Trans., 1779. 
 
550 IMBEDDING OF THE REMAINS OF MAN AND [On. XLVIL 
 
 of-war was stranded on the coast of East Lothian, and went 
 to pieces. About thirty-five years afterwards a violent storm 
 laid bare a part of the wreck, and threw up near the place 
 several masses, ' consisting of iron, ropes, and balls,' covered 
 over with ochreous sand, concreted and hardened into a kind 
 of stone. The substance of the rope w*as very little altered. 
 The consolidated sand retained perfect impressions of parts of 
 an iron ring, ' just as impressions of extraneous fossil bodies 
 are found in various kinds of strata.'* 
 
 After a storm in the year 1824, which occasioned a con- 
 siderable shifting of the sands near St. Andrew's, in Scotland, 
 a gun-barrel of ancient construction was found, which is con- 
 jectured to have belonged to one of the wrecked vessels of 
 the Spanish Armada. It is now in the museum of the Anti- 
 quarian Society of Scotland, and is incrusted over by a thin 
 coating of sand, the grains of which are cemented by brown 
 ferruginous matter. Attached to this coating are fragments 
 of various shells, as of the common Cardium, Mya, &c. 
 
 Many other examples are recorded of iron instruments 
 taken up from the bed of the sea near the British coast, 
 incased by a thick coating of conglomerate, consisting of 
 pebbles and sand, cemented by oxide of iron. 
 
 Dr. Davy describes a bronze helmet, of the antique Grecian 
 form, taken up in 1825, from a shallow part of the sea, 
 between the citadel of Corfu and the village of Castrades. 
 Both the interior and exterior of the helmet were partially 
 incrusted with shells and a deposit of carbonate of lime. The 
 surface generally, both under the incrustation and where 
 freed from it, was of a variegated colour, mottled with spots 
 of green, dirty white, and red. On minute inspection with a 
 lens, the green and red patches proved to consist of crystals 
 of the red oxide and carbonate of copper, and the dirty white 
 chiefly of oxide of tin. 
 
 The mineralising process, says Dr. Davy, which has pro- 
 duced these new combinations, has, in general, penetrated 
 very little into the substance of the helmet. The incrustation 
 and rust removed, the metal is found bright beneath ; in 
 
 * Phil. Trans., vol. Ixix. 1779. 
 
CH. XLVIL] HIS WORKS IN SUBAQUEOUS STRATA. 551 
 
 some places considerably corroded, in others very slightly. 
 It proves, on analysis, to be copper alloyed with 18- 5 per 
 cent, of tin. Its colour is that of our common brass, and it 
 possesses a considerable degree of flexibility. 
 
 * It is a curious question,' he adds, ' how the crystals were 
 formed in the helmet, and on the adhering calcareous deposit. 
 There being no reason to suppose deposition from solution, 
 are we not under the necessity of inferring, that the mineral- 
 ising process depends on a small motion and separation of 
 the particles of the original compound ? This motion may 
 have been due to the operation of electro-chemical powers 
 which may have separated the different metals of the alloy.'* 
 
 Millions of silver dollars and other coins have been some- 
 times submerged in a single ship, and on these, when they 
 happen to be enveloped in a matrix capable of protecting 
 them from chemical changes, much information of historical 
 interest will remain inscribed, and endure for periods as inde- 
 finite as have the delicate markings of zoophytes or lapidified 
 plants in some of the ancient secondary rocks. In almost 
 every large ship, moreover, there are some precious stones set 
 in seals, and other articles of use and ornament composed of 
 the hardest substances in nature, on which letters and various 
 images are carved engravings which they may retain when 
 included in subaqueous strata, as long as a crystal preserves 
 its natural form. 
 
 It was, therefore, a splendid boast, that the deeds of the 
 English chivalry at Agincourt made Henry's chronicle 
 
 as rich with praise 
 
 As is the ooze and bottom of the deep 
 With sunken wreck and sumless treasuries ; 
 
 for it is probable that a greater number of monuments of 
 the skill and industry of man will, in the course of ages, be 
 collected together in the bed of the ocean, than will exist at 
 any one time on the surface of the continents.* 
 
 * Phil. Trans., 1826, part ii. p. 55. 
 
552 IMBEDDING OF THE REMAINS OF MAN AND [Cn. XLVII. 
 
 EFFECTS OF THE SUBSIDENCE OF LAND, IN IMBEDDING CITIES 
 AND FORESTS IN SUBAQUEOUS STRATA. 
 
 We have hitherto considered the transportation of plants 
 and animals from the land by aqueous agents, and their in- 
 humation in lacustrine or submarine deposits, and we may 
 now enquire what tendency the subsidence of tracts of land 
 may have to produce analogous effects. Several examples of 
 the sinking down of buildings, and portions of towns near 
 the shore, to various depths beneath the level of the sea 
 during subterranean movements, were enumerated in the first 
 volume, Chapter XXIV. The events alluded to were comprised 
 within a brief portion of the historical period, and confined 
 to a small number of the regions of active volcanos. Yet 
 these authentic facts, relating merely to the last century and 
 a half, gave indications of considerable changes in the phy- 
 sical geography of the globe, and we are not to suppose that 
 these were the only spots throughout the surrounding land 
 and sea which suffered similar depressions. 
 
 If, during the short period since South America has been 
 colonised by Europeans, we have proof of alterations of level 
 at the three principal ports on the western shores, Callao, 
 Valparaiso, and Conception,* we cannot for a moment suspect 
 that these cities, so distant from each other, have been 
 selected as the peculiar points where the desolating power 
 of the earthquake has expended its chief fury. On con- 
 sidering how small is the area occupied by the seaports of 
 this disturbed region points where alone each slight change 
 of the relative level of the sea and land can be recognised, 
 and reflecting on the proofs in our possession of the local 
 revolutions that have happened on the site of each port, 
 within the last century and a half, our conceptions must be 
 greatly exalted respecting the magnitude of the alterations 
 which the country between the Andes and the sea may 
 have undergone, even in the course of the last six thousand 
 years. 
 
 Cutch earthquake. The manner in which a large extent of 
 surface may be submerged, so that the terrestrial plants and 
 
 * See above, pp. -90, 94, 154, 156. 
 
CH.XLVH.] HIS WORKS IN SUBAQUEOUS STRATA. 553 
 
 animals may be imbedded in subaqueous strata, cannot be 
 better illustrated than by the earthquake of Cutch, in 1819, 
 before alluded to (p. 97). It is stated, that, for some years 
 after that earthquake, the withered tamarisks and other 
 shrubs protruded their tops above the waves, in parts of the 
 lagoon formed by subsidence, on the site of the village of 
 Sindree and its environs ; but, after the flood of 1826, they 
 were seen no longer. Every geologist will at once perceive 
 that forests sunk by such subterranean movements may be- 
 come imbedded in subaqueous deposits, both fluviatile and 
 marine, and the trees may still remain erect, or sometimes 
 the roots and part of the trunks may continue in their 
 original position, while the current may have broken off, or 
 levelled with the ground, their upper stems and branches. 
 
 Buildings how preserved under water. Some of the buildings 
 which have at different times subsided beneath the level of 
 the sea have been immediately covered up to a certain extent 
 with strata of volcanic matter showered down upon them. 
 Such was the case at Tomboro in Sumbawa, in the present 
 century, and at the site of the Temple of Serapis, in the 
 environs of Puzzuoli, probably about the 12th century. The 
 entrance of a river charged with sediment in the vicinity 
 may still more frequently occasion the rapid envelopment of 
 buildings in regularly stratified formations. But, if no foreign 
 matter be introduced, the buildings, when once removed to 
 a depth where the action of the waves is insensible, and 
 where no great current happens to flow, may last for indefi- 
 nite periods, and be as durable as the floor of the ocean itself, 
 which may often be composed of the very same materials. 
 There is no reason to doubt the tradition mentioned by the 
 classic writers, that the submerged Grecian towns of Bura 
 and Helice were seen under water; and ruins of old sub- 
 merged towns are mentioned by Captain Spratt as being 
 visible in the sea off the eastern extremity of Crete or Candia. 
 It has been already mentioned that different eye-witnesses 
 have observed the houses of Port Royal, at the bottom of the 
 sea, at intervals of 88, 101, and 143 years after the convul- 
 sion of 1692 (p. 160). 
 
 Buried temples of Cashmere. The celebrated valley of 
 
554: IMBEDDING OF THE EEMAINS OF MAN AND [On. XLVII. 
 
 Cashmere (or Kashmir) in India, situated at the southern foot 
 of the Himalaya range, is about 60 miles in length, and 20 
 in breadth, surrounded by mountains which rise abruptly 
 from the plain to the height of about 5,000 feet. In the 
 cliffs of the river Jelam and its tributaries, which traverse 
 this beautiful valley, strata consisting of fine clay, sand, soft 
 sandstone, pebbles, and conglomerate are exposed to view. 
 They contain freshwater shells, of the genera Lymneus, 
 Paludina, and Cyrena, with landshells, all of recent species, 
 and are precisely such deposits as would be formed if the 
 whole valley were now converted into a great lake, and if the 
 numerous rivers and torrents descending from the surround- 
 ing mountains were allowed sufficient time to fill up the lake- 
 basin with fine sediment and gravel. Fragments of pottery 
 met with at the depth of 40 and 50 feet in this lacustrine 
 formation show that the upper part of it at least has accumu- 
 lated within the human epoch. 
 
 Dr. Thomas Thomson, who visited Cashmere in 1848, 
 observes that several of the lakes which still exist in the great 
 valley, such as that near the town of Cashmere, five miles in 
 diameter, and some others, are deeper than the adjoining 
 river-channels, and may have been formed by subsidence 
 during the numerous earthquakes which have convulsed that 
 region in the course of the last 2,000 years. It is also pro- 
 bable that the freshwater strata seen to extend far and wide 
 over the whole of Cashmere originated not in one continuous 
 sheet of water once occupying the entire valley, but in many 
 lakes of limited area, formed and filled in succession. Among 
 other proofs of such lake-basins of moderate dimensions 
 having once existed and having been converted into land at 
 different periods, Dr. Thomson mentions that the ruins of 
 Avantipura, not far from the modern village of that name, 
 stand on an older freshwater deposit at the base of the 
 mountains, and terminate abruptly towards the plain in a 
 straight line, such as admits of 110 other explanation than by 
 supposing that the advance of the town in that direction was 
 arrested by a lake, now drained or represented only by a 
 marsh. In that neighbourhood, as very generally throughout 
 Cashmere, the rivers run in channels or alluvial flats, bounded 
 
OH. XL VII.] HIS WORKS IN SUBAQUEOUS STRATA. 555 
 
 by cliffs of lacustrine strata, horizontally stratified, and these 
 strata form low table-lands from 20 to 50 feet high between 
 the different watercourses. On a table-land of this kind 
 near Avantipura, portions of two buried temples are seen, 
 which have been partially explored by Major Cunningham, 
 who, in 1847, discovered that in one of the buildings a mag- 
 nificent colonnade of seventy-four pillars is preserved under- 
 ground. He exposed to view three of the pillars in a cavity 
 still open. All the architectural decorations below the level 
 of the soil are as perfect and fresh-looking as when first 
 executed. The spacious quadrangle must have been silted 
 up gradually at first, for some unsightly alterations, not in 
 accordance with the general plan and style of architecture, 
 were detected, evidently of subsequent date, and such as could 
 only have been required when the water and sediment had 
 already gained a certain height in the interior of the temple. 
 This edifice is supposed to have been erected about the 
 year 850 of our era, and was certainly submerged before the 
 year 1416, when the Mahomedan king, Sikandar, called 
 Butshikan or the idol-breaker, destroyed all the images of 
 Hindoo temples in Cashmere. Ferishta the historian parti- 
 cularly alludes to Sikandar having demolished every Cash- 
 merian temple save one, dedicated to Mahadeva, which 
 escaped f in consequence of its foundations being below the 
 neighbouring water.' The unharmed condition of the 
 human-headed birds and other images in the buried edifice 
 near Avantipura leave no doubt that they escaped the fury 
 of the iconoclast by being under water, and perhaps silted up 
 before the date of his conquest.* 
 
 MODERN ORIGIN OF MAN AS INFERRED FROM GEOLOGICAL 
 EVIDENCE. 
 
 Bishop Berkeley on the recent date of the creation of man. 
 Bishop Berkeley, in a memorable passage written more than 
 a century ago, inferred, on grounds which may be termed 
 strictly geological, the recent date of the creation of man. 
 
 * Thomson's Western Himalaya and ningham, vol. xvii. Journ. Asiat. Soc. 
 Thibet, p. 292. London, 1852. Cnn- Bengal, pp. 241, 277. 
 
556 IMBEDDING OF THE REMAINS OF MAN AND [On. XLVII. 
 
 6 To anyone,' says he, c who considers that on digging into 
 the earth, such quantities of shells, and in some places, bones 
 and horns of animals, are found sound and entire, after hav- 
 ing lain there in all probability some thousands of years, it 
 should seem probable that guns, medals, and implements in 
 metal or stone might have lasted entire, buried under ground 
 forty or fifty thousand years, if the world had been so old. 
 How comes it then to pass that no remains are found, no 
 antiquities of those numerous ages preceding the Scripture 
 accounts of time ; that no fragments of buildings, no public 
 monuments, no intaglios, cameos, statues, basso-relievos, 
 medals, inscriptions, utensils, or artificial works of any kind, 
 are ever discovered, which may bear testimony to the exist- 
 ence of those mighty empires, those successions of monarchs, 
 heroes, and demi-gods, for so many thousand years ? Let us 
 look forward and suppose ten or twenty thousand years to 
 come, during which time we will suppose that plagues, famine, 
 wars, and earthquakes shall have made great havoc in the 
 world, is it not highly probable that at the end of such a 
 period, pillars, vases, and statues now in being of granite, or 
 porphyry, or jasper (stones of such hardness as we know 
 them to have lasted 2,000 years above ground, without any 
 considerable alteration), would bear record of these and past 
 ages ? Or that some of our current coins might then be dug 
 up, or old walls and the foundations of buildings show them- 
 selves, as well as the shells and stones of the primeval world, 
 which are preserved down to our times ? * 
 
 We may with confidence anticipate, like Berkeley, that if 
 the duration of the planet is indefinitely protracted, many 
 edifices and implements of human workmanship and the 
 skeletons of men will be entombed in freshwater, marine, 
 and volcanic strata, and will continue to exist even when a 
 great part of the present mountains, continents, and seas shall 
 have disappeared. The earth's crust must be remodelled 
 more than once before all the memorials of man which are 
 continually becoming entombed in the rocks now forming will 
 be destroyed. One complete revolution will be inadequate to 
 
 * Alciphron, or the Minute Philosopher, vol. ii. pp. 84, 85. 1732. 
 
CH. XLVIL] HIS WORKS IN SUBAQUEOUS STRATA. 557 
 
 efface every monument of our existence ; for many works of art 
 might enter again and again into the formations of succes- 
 sive eras, and escape obliteration even though the very rocks 
 in which they had been for ages imbedded were destroyed, 
 just as pebbles included in the conglomerates of one epoch 
 often contain the organised remains of beings which flourished 
 during a prior era. 
 
 Yet it is no less true, as a late distinguished philosopher 
 has declared, ' that none of the works of a mortal being can 
 be eternal.' They are in the first place wrested from the 
 hands of man, and lost as far as regards their subserviency 
 to his use, by the instrumentality of those very causes which 
 place them in situations where they are enabled to endure for 
 indefinite periods. And even when they have been included 
 in rocky strata, when they have been made to enter as it 
 were into the solid framework of the globe itself, they 
 must nevertheless eventually perish ; for every year some 
 portion of the earth's crust is shattered by earthquakes, or 
 melted by volcanic fire, or ground to dust by the moving 
 waters on the surface. ' The river of Lethe,' as Bacon 
 eloquently remarks, ' runneth as well above ground as 
 below.' * 
 
 Monuments of pre-historic man in Europe. The reader will 
 see from what was said in the forty- third chapter, that although 
 we might expect man to become cosmopolitan as soon as he 
 had acquired such intellectual superiority as belongs even 
 to the lowest of the human races now inhabiting the globe, 
 yet so long as he was slightly inferior to these races, he may 
 have continued for an indefinite time restricted to one limited 
 area, like the living species of anthropomorphous mammalia. 
 Even if he existed as a rational being before the close of the 
 Pliocene Period, we have no right to assume in the present 
 state of science that we should have obtained geological evi- 
 dence of his existence. When treating of the changes of 
 climate in the first volume, I gave some account (p. 177) of 
 the results of the joint investigations of the geologist and 
 archgeologist in regard to the remains of pre-historic man. It 
 
 * Essay on the Vicissitude of Things. 
 
558 IMBEDDING OF THE EEMAINS OF MAN AND [On. XLVII. 
 
 will there be seen that all these remains belong to the latter 
 part of that modern period in geology which I have called 
 Post-tertiary, when all the shells, marine and freshwater, 
 were already of the same species as those now living. 
 
 The age of Iron was preceded in Europe by that of Bronze, 
 when tools of that mixed metal were in use. These bronze 
 weapons prevailed in Switzerland and Gaul long before the 
 Roman invasion of those countries. Implements of the same 
 mixture of copper and tin occur in many of the Swiss lake- 
 villages and in the peat-mosses of Great Britain, Ireland, and 
 Scandinavia. But coins are entirely absent, and no proofs of 
 the art of writing or of letters having been invented have as 
 yet been brought to light. Some of the pottery of the Bronze 
 age is said to show marks of the potter's wheel, but the 
 greater part of it was made by hand. Professor Nilsson long 
 ago observed that the handles of the swords as well as the 
 bracelets of the Bronze age indicate that the size of the race 
 which used them was smaller than that of the present inhab- 
 itants of Northern Europe. Many animals had been domes- 
 ticated by man in this period, as is shown by the bones pre- 
 served in certain Swiss lake-dwellings ; several cereals also 
 and fruits were cultivated. Gold, amber, and glass were in 
 use for ornamental purposes, but there is no evidence that 
 silver, zinc, and lead were known. In the Swiss lake-villages 
 of the antecedent Stone period called Neolithic, as being 
 newer than a still older age of stone, men were evidently 
 ignorant of the art of metallurgy. Polished axes commonly 
 called Celts, chisels, and other tools, were so abundant in 
 Northern and Western Europe that the Dublin museum con- 
 tains more than 2 ? 000 of them, that of Copenhagen more 
 than 10,000, and that of Stockholm not fewer than 15,000.* 
 
 The Danish shell-mounds or kitchen-middens, as well as 
 many of the Swiss lake-dwellings, and a large part of the 
 European peat, belong to this Neolithic period, but none 
 of the polished implements of this age occur in the river- 
 drift gravel-beds, nor in association with extinct mammalia. 
 Hand-made pottery was in use ; the ox, sheep, goat, pig and 
 
 * Sir J. Lubbock, Introchiction to Translation of Nilsson's ' Primitive Inhab- 
 itants of Scandinavia,' p. xxiv. 
 
CH. XLVJL] HIS WOEKS IN SUBAQUEOUS STEATA. 559 
 
 dog were already domesticated, agriculture had commenced, 
 and flax was cultivated and woven into tissues. 
 
 Next in our retrospective survey we come to the monuments 
 of what M. Lartet has called the Kern-deer period, when that 
 animal abounded in the South of France. 
 
 To this era belong the caves of the Dordogne in central 
 France, in which MM. Lartet, Christy, and others have ob- 
 tained thousands of implements made out of stone, bone, and 
 horn without a trace of any associated pottery, still less of 
 metallic tools, or polished stone implements. M. Lartet 
 found in one cave of this period at La Madeleine a fragment 
 of mammoth tusk on which was rudely carved a representa- 
 tion of the animal itself; a fact which seems to prove that this 
 species coexisted with these cave-men. Traces also of the 
 musk-ox and cave-lion have been met with in the same caves, 
 but some doubts are still entertained whether these quadrupeds 
 were contemporary with the men of the Rein-deer period. 
 This period may be considered as intermediate between the 
 Neolithic and Palseolithic ages, but it has been classed pro- 
 visionally by Sir J. Lubbock as Palseolithic. The climate 
 then prevailing in the south of Europe was evidently much 
 colder than it is now, but the state of physical geography 
 has not since undergone any material alteration. 
 
 Lastly we arrive at the still older monuments of the Palseo- 
 lithic Period properly so called, which consist chiefly of un- 
 polished stone implements buried in ancient river-gravels and 
 in the mud and stalagmite of caves. Both the gravel and the 
 caves are now so situated in their relation to the present 
 drainage and geography of the countries where they occur as 
 to imply a great lapse of intervening time during which the 
 erosive power of rivers has been active in deepening the 
 valleys. The implements of this age in Western Europe are 
 chiefly composed of chalk-flint more rarely of chert from the 
 greensand. Besides being unpolished they differ in shape 
 from those of the Neolithic age.* They are associated with 
 remains of the mammoth, the woolly-haired rhinoceros, the 
 hippopotamus, the musk-ox, and many other quadrupeds of 
 
 * See Lyell's ' Antiquity of Man,' pp. 114 and 118, and Lubbock's 'Pre-historic 
 Times.' 
 
560 IMBEDDING OF THE REMAINS OF MAN AND [On. XLVIL 
 
 extinct and living species. No pottery has been found strictly 
 referable to this era, and there is an entire absence of 
 metallic weapons. 
 
 The beds of gravel often called drift, which contain anti- 
 quities of this age, may be said to have been deposited by the 
 existing rivers, when these ran in the same direction as at 
 present, and drained the same areas, but before the valleys 
 had been scooped out to their present depth. The height 
 above the present alluvial plains at which the old drift occurs 
 is often no more than 20 or 30 feet, but sometimes 100 or even 
 200 feet. Flint flakes having a fine cutting edge, evidently 
 chipped off by the hand of man, are met with not only in the 
 old drift, but in formations of the Neolithic and Bronze ages, 
 for they afford the finest cutting edge that was obtainable 
 before the invention of steel. In the caves of this early Stone 
 period implements of the same antique type, with fossil skele- 
 tons of man, have been detected, agreeing, as before hinted, 
 (p. 487) in osteological character with some of the existing 
 races of man. It has been estimated that the number of 
 flint implements of the Palaeolithic type already found in 
 northern France and southern England, exclusive of flakes, is 
 not less than 3,000.* No similar tools have been met with 
 in Denmark, Sweden, or Norway, where Nilsson, Thomsen, 
 and other antiquaries have collected with so much care the 
 relics of the Stone age. Hence it is supposed that Palaeo- 
 lithic Man never penetrated into Scandinavia, which may 
 perhaps have been as much covered with ice and snow as the 
 greater part of Greenland is at present. 
 
 Palaeolithic implements in the drift of the south of Hampshire. 
 Flint implements of the normal type of the Palaeolithic 
 period have been lately found in the south of Hampshire, 
 not in caves nor in old river-gravels within the limits of 
 existing valleys, but in a tabular mass of drift which caps the 
 Tertiary strata, and which is intersected both by the Solent 
 and by the valleys of all the rivers which flow into that channel 
 of the sea. The position of these implements, to which the 
 archaeologists of Salisbury have called our attention within the 
 
 * Sir J. Lubbock, Introduction to Nilsson' s ' Primitive Inhabitants of Scandi- 
 navia,' p. xx. 
 
Cn. XLVIL] HIS WORKS IN SUBAQUEOUS STEATA. 561 
 
 last four years, attests perhaps in a more striking manner the 
 antiquity of pre-historic man in Europe than any other monu- 
 ment of the earlier Stone age yet discovered. The great bed 
 of gravel resting on Eocene Tertiary strata in which these 
 implements have been found, consists in most places of half- 
 rolled or semi-angular chalk-flints, mixed with rounded 
 pebbles washed out of the Tertiary strata. But this drift, 
 although often continuous over wide areas, is not everywhere 
 present, nor does it always present the same characters. The 
 first flint implements found in it were discovered mid- way 
 between Gosport and Southampton, by Mr. James Brown of 
 Salisbury, in May 1864, included in gravel from 8 to 12 
 feet thick, capping a cliff which at its greatest height is 35 
 feet above high-water mark. I have visited this spot, which 
 had previously been seen by Messrs. Prestwich and Evans. 
 The flint-tools exactly resemble those found at Abbeville 
 and Amiens in France, being some of them of the oval, and 
 others of the lanceolate form. Many of them exhibit the 
 same colours and ochreous stain as do the flints in the gravel 
 in which they lay. A fine series of these implements, from 
 the Hampshire cliffs, may now be seen in the Blackmore 
 Museum at Salisbury. 
 
 In the gravel capping the cliffs alluded to are blocks of 
 sandstone of various sizes, some of enormous dimensions, 
 more than 20 feet in circumference and from 1 to 2J feet 
 thick. They have probably not travelled far, being a portion 
 of the wreck of the Eocene strata which have suffered much 
 denudation. Nevertheless to explain how they and the 
 stone implements became enveloped in the debris of chalk- 
 flints, we must have recourse to ice, which may have been 
 frozen on to them in winter, so as to give them buoyancy 
 and enable rivers or the sea to transport them to slight 
 distances from their original site. An extreme climate, 
 causing a vast accumulation of snow during a cold winter, 
 and great annual floods when this snow was suddenly melted 
 in the beginning of the warm season, may best account for 
 the destruction of large masses of chalk in the upland country, 
 and the spreading over the ancient surface of the flinty 
 material originally dispersed in layers through the soft chalk 
 
 VOL. II. 
 
5G2 IMBEDDING OF THE REMAINS OF MAN AND [On. XL VII. 
 
 The occasional occurrence of unrolled chalk-flints in the 
 gravel in places where they must have travelled twelve miles 
 from their nearest source, also implies the aid of ice-action. 
 The transverse valleys now intersecting the region near the 
 coast where the flint tools are found, near Gosport, must 
 have been cut through the Tertiary strata, after the over- 
 lying gravel had been superimposed, for this last forms a flat 
 table-land between the valleys. 
 
 On the whole we may infer that not only the valleys oi 
 the smaller streams near Gosport, but those of the Test 
 (or Southampton river) and of the stream which enters at 
 Lymington, and those of the rivers Avon and Stour, which 
 reach the Solent at Christchurch, as well as the Bourne- 
 mouth valley, have all been excavated since Palseolithic man 
 inhabited this region ; for not only at various points east oi 
 the Southampton estuary, but west of it also on both sides 
 of the opening at Bournemouth, flint tools of the ancient 
 type have been met with in the gravel capping the cliffs. The 
 gravel from which the flint tool was taken at Bournemouth 
 is about 100 feet above the level of the sea ; as I ascertained 
 after examining the spot in 1867.* 
 
 The gravel consists in great part of pebbles derived from 
 Tertiary strata ; and if it was originally spread out by rivers, 
 the course of the drainage must since have been altered to 
 such an extent that it is not easy to trace any connection 
 between the old watercourses and those of the existing 
 valleys. 
 
 Lastly, I learn from Mr. Evans that Mr. Thomas Codrington 
 has just discovered (Feb. 8, 1868), an oval flint implement in 
 gravel at the top of the Eorelaiid cliff on the most eastern 
 point of the Isle of Wight five miles south-east of Eyde. It 
 is of the true Palseolithic type, and the gravel in which it is 
 imbedded at the height of about 80 feet above the level oi 
 the sea, mav, as Mr. Evans suggests, have once extended to 
 the cliffs near Gosport ; in which case we should have to infer 
 
 * Mr. Alfred Stevens first dug out a soon afterwards obtained two other 
 
 hatchet (April, 1866) from this gravel similar implements from gravel west 
 
 at the top of the sea-cliff east of the of the Bournemouth valley. 
 Bournemouth opening. Dr. Blackmore 
 
Cu. XLVII.] HIS WORKS IX SUBAQUEOUS STRATA. 5C3 
 
 that the channel called the Solent had not yet been scooped 
 out when this region was inhabited by Palaeolithic man. The 
 gravel found at Freshwater at the west end of the Isle of 
 Wight, in which the remains of the mammoth have been 
 detected, is probably of the same date. 
 
 If we ascend the Avon from Christchurch to Salisbury 
 about 30 miles to the north, we find in gravels at various 
 heights above the river, and in old fluviatile alluvium, flint 
 tools of the same Palaeolithic type. One of these was taken 
 out by Dr. Blackmore from beneath the remains of a mam- 
 moth, at Fisherton, near Salisbury. The remains of no less 
 than 21 species of mammalia have also been detected at the 
 same place, the greatest number, perhaps, obtained in any one 
 spot in Great Britain. The associated land and freshwater 
 shells belong to 31 species, and are all still living in England, 
 although the quadrupeds imply a colder climate. Among 
 these are the mammoth and woolly-haired rhinoceros, the 
 rein-deer, and Norwegian lemming, the Greenland lemming, 
 and another species of the same family, the Spermophilus, 
 allied to the marmot. Of this last 13 individuals have 
 been found, some of the skeletons being perfect, and lying, 
 as remarked by Dr. Blackmore, in the curved attitude of 
 hibernation, as may now be seen in the Blackmore Museum. 
 Besides the bones of quadrupeds, the femur and coracoid 
 bones of the wild goose (Anser palustris), have been met with, 
 and some egg-shells corresponding in size with the eggs of 
 the wild goose and wild duck. These shells are in part 
 covered with superficial incrustations. As the wild goose 
 now resorts to arctic regions in the breeding season, the 
 occurrence of its eggs at Fisherton seems to imply a cold 
 climate such as would have suited the lemming and 
 marmot.* 
 
 To conclude, there are three independent classes of evi- 
 dence, which in this part of Hampshire point distinctly to 
 the vast antiquity of Palaeolithic man. First, the great 
 denudation of the Chalk and Tertiary strata, and the im- 
 portant changes in the shape and depth of the valleys and 
 the contour of the sea-coast which have since occurred in 
 
 * Evans, Geol. Quart. Journ., p. 193, Aug. 1864. 
 O o 2 
 
564 IMBEDDING OF THE KEMAINS OF MAN. [Cn. XLVIL 
 
 Hampsliire ; secondly, a marked change in the fauna, by the 
 dying out of so many conspicuous species of quadrupeds ; 
 and thirdly, the change of climate from a colder to a warmer 
 temperature, implied by the former presence of northern 
 animals, and by the ice-borne erratics of the drift. 
 
 Age of pottery buried in upraised marine strata in Sardinia. 
 I have elsewhere called attention * to a marine formation 
 described by Count Albert de la Marmora as occurring at 
 Cagliari, on the southern coast of the island of Sardinia, at 
 the height of more than 300 feet above the level of the 
 Mediterranean. In this deposit some rude fragments of 
 pottery were found together with a flattened ball of baked 
 earthenware, with a hole through the axis, supposed to have 
 been used for weighting fishing-nets. These works of art 
 were associated with marine shells all of living species, the 
 oysters and mussels having both valves united together. I 
 know of no other instance in Europe of a sea-bottom of the 
 human period having been lifted up 300 feet above its former 
 level ; but in countries like Sardinia, where the latest vol- 
 canic cones are of Newer Pliocene, if not of Post-Pliocene 
 date, such an upheaval may not imply a greater antiquity 
 than may belong to Neolithic times. f 
 
 * See 'Antiquity of Man' p. 177. Sardinia, I think it most probable that 
 
 t In my 'Antiquity of Man' (p. 177) the bone-breccias in question maybe 
 
 I inferred that these upraised marine older than the marine strata in which 
 
 strata containing pottery were as old as the works of art are imbedded. This 
 
 certain bone-breccias near Cagliari, in question has now acquired increased im- 
 
 which the remains of two species of ex- portance since it has been determined 
 
 tinct mammalia have been found ; but that hitherto no pottery (see above, 
 
 on reconsidering De la Marmora's ac- p. 560) has been detected in Palaeolithic 
 
 count of the geology of that part of deposits in the North of Europe. 
 
565 
 
 CHAPTEE XLYIII. 
 
 IMBEDDING OP AQUATIC SPECIES IN SUBAQUEOUS STRATA. 
 
 INHUMATION OF FRESHWATER PLANTS AND ANIMALS SHELL-MARL FOSSI- 
 LISED SEED-VESSELS AND STEMS OF CHARA RECENT DEPOSITS IN AMERICAN 
 
 LAKES FRESHWATER SPECIES DRIFTED INTO SEAS AND ESTUARIES LEWES 
 
 LEVELS ALTERNATIONS OF MARINE AND FRESHWATER STRATA, HOW CAUSED 
 
 IMBEDDING OF MARINE PLANTS AND ANIMALS CETACEA STRANDED ON OUR 
 
 SHORES LITTORAL AND ESTUARY TESTACEA SWEPT INTO THE DEEP SEA 
 
 BURROWING SHELLS LIVING TESTACEA FOUND AT CONSIDERABLE DEPTHS 
 
 BLENDING OF ORGANIC REMAINS OF DIFFERENT AGES. 
 
 HAVING treated of the imbedding of terrestrial plants and 
 animals, and of human remains, in deposits now forming 
 beneath the waters, I come next to consider iii what manner 
 aquatic species may be entombed in strata formed in their 
 own element. 
 
 Freshwater plants and animals. The remains of species 
 belonging to those genera of the animal and vegetable 
 kingdoms which are more or less exclusively confined to 
 fresh water are for the most part preserved in the beds of 
 lakes or estuaries, but they are oftentimes swept down by 
 rivers into the sea, and there intermingled with the exuviae 
 of marine races. The phenomena attending their inhumation 
 in lacustrine deposits are sometimes revealed to our observ- 
 ation by the drainage of small lakes, such as are those in 
 Scotland, which have been laid dry for the sake of obtain- 
 ing shell-marl for agricultural uses. 
 
 In these modern formations, as seen in Forfarshire, two or 
 three beds of calcareous marl are sometimes observed separated 
 from each other by layers of drift peat, sand, or fissile clay. 
 The marl often consists almost entirely of an aggregate of 
 shells of the genera Limnea, Planorbis, Yalvata, and Cyclas, 
 of species now existing in Scotland. A considerable proportion 
 of the Testacea appear to have died very young, and few of 
 
566 
 
 IMBEDDING OF AQUATIC SPECIES [On. XL VIII. 
 
 the shells are of a size which indicates their having attained 
 a state of maturity. The shells are sometimes entirely de- 
 composed, forming a pulverulent marl ; sometimes in a state 
 of good preservation. They are frequently intermixed with 
 stems of Charse and other aquatic vegetables^ the whole being 
 matted together and compressed, forming laminae often as 
 thin as paper. 
 
 Fossilised seed-vessels and stems of Char a. As the Chara is 
 an aquatic plant which occurs frequently fossil in formations 
 of different eras, and is often of much importance to the 
 geologist in characterising entire groups of strata, I shall 
 describe the manner in which I have found the recent species 
 in a petrified state. They occur in a marl-lake in Forfarshire, 
 enclosed in nodules, and sometimes in a continuous stratum 
 of a kind of travertin. 
 
 Fig. 140. 
 
 Seed-vessel of Chara hispida. 
 
 a. Part of the stem with the seed-vessel attached. Magnified. 
 
 b. Natural size of the seed-vessel. 
 
 c. Integument of the Gyrogonite, or petrified seed-vessel of Chara hispida, found in the Scotch 
 
 marl lakes. Magnified. 
 
 d. Section showing the nut within the integument. 
 
 e. Lower end of the integument to which the stem was attached. 
 
 /. Upper end of the integument to which the stigmata were attached. 
 g. One of the spiral valves of c. 
 
 The seed-vessel of these plants is remarkably tough and 
 hard, and consists of a membranous nut covered by an integu- 
 ment (d, fig. 140), both of which are spirally striated or 
 ribbed. The integument is composed of five spiral valves, of 
 
CH. XLVIIL] 
 
 IX SUBAQUEOUS STKATA. 
 
 5G7 
 
 a quadrangular form (g). In Chara hispida, whicli abounds 
 in a living state in the lakes of Forfarshire, and which has 
 become fossil in the Bakie Loch, each of the spiral valves of 
 the seed-vessel turns rather more than twice round the circum- 
 ference, the whole together making between ten and eleven 
 rings. The number of these rings differs greatly in different 
 species, but in the same appears to be very constant. 
 
 The stems of Charge occur fossil in the Scotch marl in 
 great abundance. In some species, as in Chara hispida, the 
 plant when living contains so much carbonate of lime in its 
 vegetable organisation, independently of calcareous in- 
 crustation, that it effervesces strongly with acids when dry. 
 
 Fig. 141. 
 
 Stem and branches of Chara hitpida. 
 
 a. Stem and branches of the natural size. 
 
 b. Section of the stem magnified. 
 
 c. Showing the central tube surrounded by two rings of smaller tubes. 
 
 The longitudinal strise on the stems of Chara hispida have 
 a tendency to be spiral, and as appears to be the case with 
 other species of the genus, turn always like the worm of a 
 screw from right to left, while those of the seed-vessel wind 
 round in a contrary direction. A cross section of the stem 
 exhibits a curious structure, for it is composed of a large 
 
568 IMBEDDING OF AQUATIC SPECIES [Cn. XLVIII. 
 
 tube surrounded by smaller tubes (fig. 141, b, c), as is seen 
 in some extinct as well as recent species. In the stems of 
 several species, however, there is only a single tube.* 
 
 The valves of a small animal called Cypris (C. ornata ? Lam.) 
 occur completely fossilised, like the stems of Charse, in the 
 Scotch travertin above mentioned. The same Cypris in- 
 habits the lakes and ponds of England, where, together with 
 many other species, it is not uncommon. Although extremely 
 minute, they are visible to the naked eye, and may be observed 
 in great numbers, swimming swiftly through the waters of 
 our stagnant pools and ditches. The antennae, at the end of 
 which are fine pencils of hair, are the principal organs for 
 swimming, and are moved with great rapidity. The animal 
 
 Fig. 143. 
 
 Cypris umfasciata, & living species, greatly Cypris vidua, a living species, 
 
 magnified. greatly magnified.f 
 
 a. Upper part. 6. Side view of the same. 
 
 resides within two small valves, not unlike those of a bivalve 
 mollusk, and moults its integuments annually, which the 
 conchiferous mollusk does not. The cast-off shells, resem- 
 bling thin scales, and occurring in countless myriads in 
 many ancient freshwater marls, impart to them a divi- 
 sional structure, like that so frequently derived from plates of 
 mica. 
 
 The recent strata of lacustrine origin above alluded to are 
 of very small extent, but analogous deposits on the grandest 
 scale are forming in the great Canadian lakes, as in Lakes 
 Superior and Huron, where beds of sand and clay are seen 
 
 * On Freshwater Marl, &c. By C. p. 73. 
 Lyell, Geol. Trans., vol. ii., second series, f See Desmaret's Crustacea, pi. 55. 
 
CH. XLVIIL] IN SUBAQUEOUS STRATA. 569 
 
 enclosing shells of existing species.* The Chara also plays 
 the same part in the subaqueous vegetation of North 
 America as in Europe. I observed along the borders of 
 several freshwater lakes in the state of New York a luxuriant 
 crop of this plant in clear water of moderate depth, rendering 
 the bottom as verdant as a grassy meadow. Here, therefore, 
 we may expect some of the tough seed-vessels to be preserved 
 in mud, just as we detect them fossil in the Eocene strata of 
 Hampshire, or in the neighbourhood of Paris, and many 
 other countries. 
 
 IMBEDDING OP FRESHWATER SPECIES IN ESTUARY AND 
 MARINE DEPOSITS. 
 
 In Lewes levels. We have sometimes an opportunity of 
 examining the deposits which within the historical period 
 have silted up some of our estuaries ; and excavations made 
 for wells and other purposes, where the sea has been finally 
 excluded, enable us to observe the state of the organic remains 
 in these tracts. The valley of the Ouse between Newhaven 
 and Lewes is one of several estuaries from which the sea 
 has retired within the last seven or eight centuries; and 
 here, as appears from the researches of Dr. Mantell, strata 
 30 feet and upwards in thickness have accumulated. At 
 the top, beneath the vegetable soil, is a bed of peat about 
 5 feet thick, enclosing many trunks of trees. Next below is 
 a stratum of blue clay containing freshwater shells of about 
 nine species, such as now inhabit the district. Intermixed 
 with these was observed the skeleton of a deer. Lower down, 
 the layers of blue clay contain, with the above-mentioned 
 freshwater shells, several marine species well known on 
 our coast. In the lowest beds, often at the depth of 36 feet, 
 these marine Testacea occur without the slightest inter- 
 mixture of fluviatile species, and amongst them the skull of 
 a narwal, or sea-unicorn (Monodon monoceros) , has been de- 
 tected. Underneath all these deposits is a bed of pipe-clay, 
 derived from the subjacent chalk.f 
 
 * Dr. Bigsby, Journ. of Science, &c., also Catalogue of Org. Kem., Geol. 
 No. xxxvii. pp. 262, 263. Trans, vol. iii. part i. p. 201, 2nd series. 
 
 f Mantell, Geol. of Sussex, p. 285 ; 
 
570 IMBEDDING OF AQUATIC SPECIES [On. XLVI.LL 
 
 If we had no historical information respecting the former 
 existence of an inlet of the sea, in this valley and of its 
 gradual obliteration, the inspection of the section above 
 described would show, as clearly as a written chronicle, 
 the following sequence of events. First, there was a salt- 
 water estuary peopled for many years by species of marine 
 Testacea identical with those now living, and into which 
 some of the larger Cetacea occasionally entered. Secondly, 
 the inlet grew shallower, and the water became brackish, or 
 alternately salt and fresh, so that the remains of freshwater 
 and marine shells were mingled in the blue argillaceous 
 sediment of its bottom. Thirdly, the shoaling continued 
 until the river-water prevailed, so that it was no longer hab- 
 itable by marine Testacea, but fitted only for the abode of 
 fluviatile species and aquatic insects. Fourthly, a peaty swamp 
 or morass was formed, where some trees grew, or perhaps 
 were drifted during floods, and where terrestrial quadrupeds 
 were mired. Finally, the soil being flooded by the river only 
 at distant intervals, became a verdant meadow. 
 
 In delta of Ganges and Indus. It was before stated, that 
 on the sea-coast, in the delta of the Ganges, there are eight 
 great openings, each of which has evidently, at some ancient 
 period, served in its turn as the principal channel of dis- 
 charge.* As the base of the delta is 200 miles in length, it 
 must happen that, as often as the great volume of river- 
 water is thrown into the sea by a new mouth, the sea will at 
 one point be converted from salt to fresh, and at another 
 from fresh to salt; for, with the exception of those parts 
 where the principal discharge takes place, the salt water not 
 only washes the base of the delta, but enters far into every 
 creek and lagoon. It is evident, then, that repeated alter- 
 nations of beds containing freshwater shells, with others 
 filled with marine exuvise, may here be formed. It has also 
 been shown by artesian borings at Calcutta (see Vol. I. 
 p. 478), that the delta once extended much farther than 
 now into the gulf, and that the river is only recovering from 
 the sea the ground which had been lost by subsidence at some 
 former period. Analogous phenomena must sometimes be 
 
 * Vol. I. p. 472. 
 
CH. XLVIIL] IN SUBAQUEOUS STRATA. 571 
 
 occasioned by such alternate elevation and depression as has 
 occurred in modern times in the delta of the Indus. * But 
 the subterranean movements affect but a small number of 
 the deltas formed at one period on the globe ; whereas the 
 silting up of some of the arms of great rivers and the opening 
 of others, and the consequent variation of the points where the 
 chief volume of their waters is discharged into the sea, are 
 phenomena common to almost every delta. 
 
 The variety of species of Testacea contained in the recent 
 calcareous marl of Scotland, before mentioned, is very small, 
 but the abundance of individuals extremely great, a cir- 
 cumstance very characteristic of freshwater formations in 
 general, as compared to marine ; for in the latter, as is seen 
 on sea-beaches, coral-reefs, or in the bottom of seas examined 
 by dredging, wherever the individual shells are exceedingly 
 numerous, there rarely fails to be a vast variety of species. 
 
 IMBEDDING OF THE REMAINS OF MAEINE PLANTS AND 
 ANIMALS. 
 
 Marine plants. The large banks of drift sea-weed which 
 occur on each side of the equator in the Atlantic, Pacific, and 
 Indian oceans, were before alluded to.f These, when they 
 subside, may often produce considerable beds of vegetable 
 matter. In Holland, sub-marine peat is derived from Fuci, 
 and on parts of our own coast from sea- wrack (Zostera marina). 
 In places where Algse do not generate peat, they may never- 
 theless leave traces of their form imprinted on argillaceous 
 and calcareous mud, as they are usually very tough in their 
 texture. 
 
 Sea-weeds are often cast up in such abundance on our shores 
 during heavy gales, that we cannot doubt that occasionally 
 vast numbers of them are embedded in littoral deposits now 
 in progress. We learn from the researches of Dr. Forch- 
 hammer, that besides supplying in common with land-plants 
 the materials of coal, the Algse must give rise to important 
 chemical changes in the composition of strata in which they 
 are imbedded. These plants always contain sulphuric acid, 
 
 * Page 99. t Page 392. 
 
572 IMBEDDING- OF AQUATIC SPECIES [Cn. XL VIII. 
 
 and sometimes in as large a quantity as 8J per cent., combined 
 with potash. : magnesia also and phosphoric acid are constant 
 ingredients. Whenever large masses of sea- weeds putrefy 
 in contact with ferruginous clay, sulphuret of iron, or iron 
 pyrites, is formed by the union of the sulphur of the plants 
 with the iron of the clay. Many of the mineral character- 
 istics of ancient rocks, especially the alum slates, and the 
 pyrites which occur in clay slate, and the fragments of an- 
 thracite in marine strata, may be explained by the decom- 
 position of fucoids or sea-weeds.* 
 
 Imbedding of cetacea. It is not uncommon for the larger 
 Cetacea, which can float only in a considerable depth of 
 water, to be carried during storms or high tides into 
 estuaries, or upon low shores, where, upon the retiring of 
 high water, they are stranded. Thus a narwal (Monodon 
 monoceros) was found on the beach near Boston in Lincoln- 
 shire, in the year 1800, the whole of its body buried in the 
 mud. A fisherman going to his boat saw the horn, and 
 tried to pull it out, when the animal began to stir itself. f 
 An individual of the common whale (Balcena mysticetus), 
 which measured 70 feet, came ashore near Peterhead, in 
 1682. Many individuals of the genus Balsenoptera have met 
 the same fate. It will be sufficient to refer to those cast 
 on shore in the Firth of Forth near Burntisland, and at 
 Alloa, recorded by Sibbald and Neill. The other individual 
 mentioned by Sibbald, as having come ashore at Boyne, in 
 Banffshire, was probably a razor-back. Of the genus Catodon 
 (Cachalot), Ray mentions a large one stranded on the west 
 coast of Holland in 1598, a,nd the fact is also commemorated 
 in a Dutch engraving of the time of much merit. Sibbald, 
 too, records that a herd of Cachalots, upwards of 100 in 
 number, were found stranded at Cairston, in Orkney. The 
 dead bodies of the larger Cetacea are sometimes found 
 floating on the surface of the waters, as was the case with 
 the immense whale exhibited in London in 1831. And the 
 carcass of a sea-cow or Lamantine (Halicora) was, in 1785, 
 cast ashore near Leith. 
 
 * Forchhammer, Report British As- f Fleming's Brit. Animals, p. 37; in 
 
 soc. 1844. -which work other cases are enumerated. 
 
CH. XL VIII.] 
 
 IN SUBAQUEOUS STRATA. 
 
 573 
 
 Fig. 144. 
 
 To some accident of this kind we may refer the position 
 of the skeleton of a whale, 73 feet long, which was found 
 at Airthie, on the Forth, near Stirling, imbedded in clay 20 
 feet higher than the surface of the highest tide of the river 
 Forth at the present day. From the situation of the Roman 
 station and causeways at a small distance from the spot, it 
 is concluded that the whale must have been stranded there 
 at a period prior to the Christian era.* 
 
 Marine reptiles. Some singular fossils have been dis- 
 covered in the Island of Ascension in a 
 stone said to be continually forming on 
 the beach, where the waves throw up 
 small rounded fragments of shells and 
 corals, which, in the course of time, 
 become firmly agglutinated together, 
 and constitute a stone used largely for 
 building and making lime. In a quarry 
 on the NW. side of the island, about 
 100 yards from the sea, some fossil eggs 
 of turtles have been discovered in the 
 hard rock thus formed. The eggs must have been nearly 
 hatched at the time when they perished ; for the bones of the 
 young turtle are seen in the interior, with their shape fully 
 developed, the interstices between the bones being entirely 
 filled with grains of sand, which are cemented together, so 
 that when the egg-shells are removed perfect casts of their 
 form remain in stone. In the single specimen here figured 
 (fig. 144), which is only five inches in its longest diameter, 
 no less than seven eggs are preserved. J 
 
 To explain the state in which they occur fossil, it seems 
 necessary to suppose that after the eggs were almost hatched 
 in the warm sand, a great wave threw upon them so much 
 
 the 
 
 * Quart. Journ. of Lit. Sci., &c., No. 
 xv. p. 172. Oct. 1819. 
 
 f This specimen has been presented 
 by Mr. Lonsdale to the Geographical 
 Society of London. 
 
 J The most conspicuous of the bones 
 represented within the shell in fig. 145, 
 appear to be the clavicle and coracoid 
 bone. They are hollow ; and for this 
 
 reason resemble, at first sight, the 
 bones of birds rather than of reptiles ; 
 for the latter have no medullary cavity. 
 Prof. Owen, in order to elucidate this 
 point, dissected for me a very young 
 turtle, and found that the exterior por- 
 tion only of the bones was ossified, the 
 interior being still filled with cartilage. 
 
574 IMBEDDING OF AQUATIC SPECIES [On. XLVIIL 
 
 more sand as to prevent the rays of the sun from penetrating, 
 so that the yolk was chilled and deprived of vitality. The 
 shells were perhaps slightly broken at the same time, so that 
 small grains of sand might gradually be introduced into the 
 interior by water as it percolated through the beach. 
 
 Marine testacea. The aquatic animals and plants which 
 inhabit an estuary are liable, like the trees and land animals 
 
 Fig. 145. 
 
 One of the eggs in fig. 144, of the natural size, showing the bones of the foetus which had 
 been nearly hatched. 
 
 which people the alluvial plains of a great river, to be swept 
 from time to time far into the deep ; for as a river is per- 
 petually shifting its course, and undermining a portion of its 
 banks with the forests which cover them, so the marine 
 current alters its direction from time to time, and bears away 
 the banks of sand and mud against which it turns its force. 
 These banks may consist in great measure of shells peculiar 
 to shallow and sometimes brackish water, which may have 
 been accumulating for centuries, until at length they are 
 carried away and spread out along the bottom of the sea, at 
 a depth at which they could not have lived and multiplied. 
 Thus littoral and estuary shells are more frequently liable, 
 even than freshwater species, to be intermixed with the ex- 
 uvise of pelagic tribes. 
 
CH. XLVIIL] IN SUBAQUEOUS STRATA. 575 
 
 After the storm of February 4, 1831, when several vessels 
 were wrecked in the estuary of the Forth, the current was 
 directed against a bed of oysters with such force, that great 
 heaps of them were thrown alive upon the beach, and re- 
 mained above high-water mark. I collected many of these 
 oysters, as also the common eatable whelks (Buccinum), 
 thrown up with them, and observed that, although still living, 
 their shells were worn by the long attrition of sand which 
 had passed over them as they lay in their native bed, and 
 which had evidently not resulted from the mere action of the 
 tempest by which they were cast ashore. 
 
 From these facts we learn that the union of the two parts 
 of a bivalve shell does not prove that it has not been trans- 
 ported to a distance ; and when we find shells worn, and with 
 all their prominent parts rubbed off, they may still have been 
 imbedded where they grew. 
 
 Burrowing shells. It sometimes appears extraordinary, 
 when we observe the violence of the breakers on our coast, 
 and see the strength of the current in removing cliffs, and 
 sweeping out new channels, that many tender and fragile 
 shells should inhabit the sea in the immediate vicinity 
 of this turmoil. But a great number' of the bivalve Tes- 
 tacea, and many also of the turbinated univalves, burrow in 
 sand or mud. The Solen and the Cardium, for example, 
 which are usually found in shallow water near the shore, 
 pierce through a soft bottom without injury to their shells ; 
 and the Pholas can drill a cavity through mud of considerable 
 hardness. The species of these and many other tribes can 
 sink, when alarmed, with considerable rapidity, often to the 
 depth of several feet, and can also penetrate upwards again 
 to the surface, if a mass of matter be heaped upon them. 
 The hurricane, therefore, may expend its fury in vain, and 
 may sweep away even the upper part of banks of sand or 
 mud, or may roll pebbles over them, and yet these Testacea 
 may remain below secure and uninjured. 
 
 Shells become fossil at considerable depths. I have already 
 stated that, at the depth of 950 fathoms, between Gibraltar 
 and Ceuta, Captain Smith found a gravelly bottom, with 
 fragments of broken shells, carried thither probably from the 
 
576 IMBEDDING OF AQUATIC SPECIES [Cn. XLVIII. 
 
 comparatively shallow parts of the neighbouring straits, 
 through which a powerful current flows. Beds of shelly sand 
 might here, in the course of ages, be accumulated several 
 thousand feet thick. But without the aid of the drifting power 
 of a current, shells may accumulate in the spot where they 
 live and die, at great depths from the surface, if sediment be 
 thrown down upon them ; for even in our own colder latitudes 
 the depths at which living marine animals abound is very 
 considerable. Captain Vidal ascertained, by soundings made 
 off Tory Island, on the north coast of Ireland, that Crustacea, 
 Starfish, and Testacea occurred at various depths between 
 50 and 100 fathoms ; and he drew up Dentalia from the 
 mud of Gralway Bay, in 230 and 240 fathoms water. 
 
 The same hydrographer discovered on the Rockhall Bank 
 large quantities of shells at depths varying from 45 to 190 
 fathoms. These shells were evidently recent, as they re- 
 tained their colours. In the same region a bed of fish-bones 
 was observed extending for two miles along the bottom of 
 the sea in 10 and 90 fathoms water. At the eastern ex- 
 tremity also of Eockhall Bank fish-bones were met with, 
 mingled with pieces of fresh shell, at the depth of 235 
 fathoms. 
 
 Analogous formations are in progress in the submarine 
 tracts extending from the Shetland Isles to the north of 
 Ireland, wherever soundings can be procured. A continuous 
 deposit of sand and mud, replete with broken and entire 
 shells, Echini, &c., has been traced for upwards of twenty 
 miles to the eastward of the Faroe Islands, usually at the 
 depth of from 40 to 100 fathoms. In one part of this 
 tract (lat. 61 50', long. 6 30') fish-bones occur in extra- 
 ordinary profusion, so that the lead cannot be drawn up 
 without some vertebrae being attached. This ' bone bed,' as 
 it was called by our surveyors, is three miles and a half in 
 length, and forty-five fathoms under water, and contains a 
 few shells intermingled with the bones. 
 
 In the British seas, the shells and other organic remains 
 lie in soft mud or loose sand and gravel ; whereas, in the bed 
 of the Adriatic, Donati found them frequently enclosed in 
 
Cu. XLVIII.] IN SUBAQUEOUS STRATA. 577 
 
 stone of recent origin. This is precisely the difference in 
 character which we might have expected to exist between 
 the British marine formations now in progress and those of 
 the Adriatic ; for calcareous and other mineral springs 
 abound in the Mediterranean and lands adjoining, while 
 they are almost entirely wanting in our own country. I 
 have already adverted to the eight regions of different depths 
 in the .ZEgeari Sea, each characterised by a peculiar assem- 
 blage of shells, which have been described by Professor E. 
 Forbes, who explored them by dredging. (See above, p. 372.) 
 
 But since Edward Forbes fixed the zero of animal life in 
 the .zEgean Sea at 300 fathoms, other observers, Captain 
 McClintock and Dr. Wallich for example, have found living 
 starfish at the depth of a thousand fathoms midway between 
 Greenland and Iceland, and Dr. Hooker in his Antarctic 
 voyage with Captain Sir J. C. Ross established the fact from 
 soundings made off Yictoria Land between lats. 71 and 78 
 south, that the bottom of the ocean was inhabited, at depths 
 of from 200 to 400 fathoms, by Crustacea, mollusca, serpulse, 
 sponges, and other iiivertebrata.* 
 
 In all these cases, it is only necessary that there should 
 be some deposition of sedimentary matter, however minute, 
 such as may be supplied by rivers draining a continent, or 
 currents preying on a line of cliffs, or melting icebergs loaded 
 with mud, sand, and boulders, in order that stratified forma- 
 tions, hundreds of feet in thickness, and replete with organic 
 remains, should result in the course of ages. 
 
 We frequently observe, on the sea-beach, very perfect 
 specimens of fossil shells, quite detached from their matrix, 
 which have been washed out of older formations, consti- 
 tuting the sea-cliffs. They may be all of extinct species, 
 like the Eocene freshwater and marine shells strewed over 
 the southern shores of Hampshire, yet when they become 
 mingled with the shells of the present period, and buried in 
 the same deposits of mud and sand, they would appear, if 
 upraised and examined by future geologists, to have been all 
 
 * ' Antiquity of Man,' p. 268. and Appendix H., p. 528. 
 VOL. II. P P 
 
578 IMBEDDING OF AQUATIC SPECIES. [Cn. XL VIII. 
 
 of the same age. That such intermixture and blending of 
 organic remains of different ages have actually taken place 
 in former times, is unquestionable, though the occurrence 
 appears to be very local and exceptional. It is, however, a 
 class of accidents more likely than almost any other to lead 
 to serious anachronisms in geological chronology. 
 
579 
 
 CHAPTER XLIX. 
 
 FORMATION OF CORAL REEFS. 
 
 GROWTH OF CORAL CHIEFLY CONFINED TO TROPICAL REGIONS PRINCIPAL 
 
 GENERA OF CORAL-BUILDING ZOOPHYTES THEIR RATE OF GROWTH SELDOM 
 
 FLOURISH AT GREATER DEPTHS THAN TWENTY FATHOMS ATOLLS OR ANNU- 
 LAR REEFS WITH LAGOONS MALDIVE ISLES ORIGIN OF THE CIRCULAR FORM 
 CORAL REEFS NOT BASED ON SUBMERGED VOLCANIC CRATERS MR. DAR- 
 WIN'S THEORY OF SUBSIDENCE IN EXPLANATION OF ATOLLS, ENCIRCLING 
 AND BARRIER REEFS WHY THE WINDWARD SIDE OF ATOLLS HIGHEST SUB- 
 SIDENCE EXPLAINS WHY ALL ATOLLS ARE NEARLY ON ONE LEVEL ALTER- 
 NATE AREAS OF ELEVATION AND SUBSIDENCE ORIGIN OF OPENINGS INTO 
 
 THE LAGOONS SIZE OF ATOLLS AND BARRIER REEFS OBJECTION TO THE 
 
 THEORY OF SUBSIDENCE CONSIDERED COMPOSITION, STRUCTURE, AND STRA- 
 TIFIED ARRANGEMENT OF ROCKS NOW FORMING IN CORAL REEFS LIME 
 WHENCE DERIVED SUPPOSED INCREASE OF CALCAREOUS MATTER IN MODERN 
 EPOCHS CONTROVERTED CONCLUDING REMARKS. 
 
 THE powers of the organic creation in modifying the form and 
 structure of the earth's crust are most conspicuously displayed 
 in the labours of the coral animals. We may compare the 
 operation of these zoophytes in the ocean to the effects pro- 
 luced on a smaller scale upon the land by the plants which 
 generate peat. In the case of the Sphagnum, the upper part 
 sregetates while the lower portion is entering into a mineral 
 mass, in which the traces of organisation remain when life 
 ias entirely ceased. In corals, in like manner, the more 
 lurable materials of the generation that has passed away 
 serve as the foundation on which the living animals continue 
 :o rear a similar structure. 
 
 The stony part of the lamelliform zoophyte may be likened 
 :o an internal skeleton; for it is always more or less sur- 
 rounded by a soft animal substance capable of expanding 
 tself ; yet, when alarmed, it has the power of contracting and 
 drawing itself almost entirely into the cells and hollows of 
 the hard coral. Although oftentimes beautifully coloured in 
 their own element, the soft parts become when taken from 
 
 p p 2 
 
580 FORMATION OF CORAL REEFS. [Cii. XLIX. 
 
 the sea nothing more in appearance than a brown slime spread 
 over the stony nucleus.* 
 
 The growth of those corals which form reefs of solid stone 
 is entirely confined to the warmer regions of the globe, rarely 
 extending beyond the tropics about two or three degrees, 
 except under peculiar circumstances, as in the Bermuda 
 Islands, in lat. 32 N"., where the Atlantic is warmer by the 
 Gulf-stream. The Caribbean seas are very coralliferous. 
 The Pacific Ocean, throughout a space comprehended between 
 the thirtieth parallels of latitude on each side of the equator, 
 is extremely productive of coral ; as also are the Arabian and 
 Persian Gulfs. Coral is also abundant in the sea between 
 the coast of Malabar and the island of Madagascar. Flinders 
 describes a reef of coral on the east coast of New Holland as 
 having a length of nearly 1,000 miles, and as being in one 
 part unbroken for a distance of 350 miles. Some groups of 
 coral islands in the Pacific are from 1,100 to 1,200 miles in 
 
 length, by 300 or 400 in 
 le< ' breadth, as the Dangerous 
 
 Archipelago, for example, and 
 that called Eadack by Kot- 
 zebue ; but the islands within 
 these spaces are always small 
 points, and often very thinly 
 sown. 
 
 ? MM. Duchassaing and Jean 
 Michelotti have lately written 
 a concise account of the dis- 
 M. B*. 6 J. Haimes. tribution of corals in relation 
 
 to the depth of the sea.f 
 
 A certain number of zoophytes are littoral and are left 
 uncovered by every low tide for instance, species of the 
 genera Zoantkes and Palytlwa. In shallow spots where a 
 certain depth of water always covers the corals, the species 
 of Porites, Astrcea, Madrepora, Solenastrcea, and Phyllangia, 
 nourish. The Mceandrince are sometimes left uncovered. All 
 these may be termed sub-littoral. At a depth of from 6 to 
 
 * Ehrenberg, Nat. und Bild. der Coralliaires des Antilles. Mem. della 
 Coralleninseln, &c., Berlin, 1834. Reale Accad. delle Scienze di Torino,; 
 
 t Supplement au Memoire sur les serie n. torn, xxiii. 
 
CH. XLIX.] RATE OF THE GROWTH OF CORAL. 581 
 
 10 feet the genera Mussa, Colpophyllia, Lithophyllia, Sym- 
 phyllia, Milleponi, c., are found, and at the depth of from 
 10 to 20 feet the species of Dichocoenia, Stephanocoenia, 
 and Desmophyllum flourish. 
 
 The distribution of particular species, in regard to the 
 depth of water in which they grow, is remarkably uniform. 
 According to Mr. Darwin, as will appear in the sequel, the 
 reef-building corals rarely live at a depth exceeding 120 feet, 
 but M. Duchassaing obtained some species of stony corals 
 at depths of from 600 to 900 feet in the Caribbean Sea. In 
 temperate climates such species as the Caryophyllia Smythi, 
 Stokes, are sub-littoral; but Dr. Duncan reminds me, and 
 the fact is of no small geological significance, when we are 
 reasoning on extinct forms, that the closely allied species 
 C. borealis now lives in deep water off the Shetlands. 
 
 Of the numerous zoophytes which are engaged in the 
 production of coral banks, some of the most common belong 
 to the Lamarckian genera Astrsea, Porites, Madrepora, 
 Millepora, Pocillopora, and Mseandrina. 
 
 Rate of the growth of coral. Very different opinions have 
 been entertained in regard to the rate at which coral reefs 
 increase. In Captain Beechey's late expedition to the Pacific, 
 no positive information could be obtained of any channel 
 having been filled up within a given period ; and it seems 
 established, that several reefs had remained for more than 
 half a century at about the same depth from the surface. 
 
 Ehrenberg also, questions the fact of channels and harbours 
 having been closed up in the Red Sea by the rapid increase 
 of coral limestone. He supposes the notion to have arisen 
 from the circumstance of havens having been occasionally 
 filled up in some places with coral sand, in others with large 
 quantities of ballast of coral rock thrown down from vessels. 
 
 The natives of the Bermuda Islands point out certain corals 
 now growing in the sea, which, according to tradition, have 
 been living in the same spots for centuries. It is supposed 
 that some of them may vie in age with the most ancient trees 
 of Europe. Ehrenberg also observed single corals of the 
 genera Mseaiidriiia and Favia, having a globular form, from 
 6 to 9 feet in diameter, ' which must (he says) be of 
 
582 
 
 FORMATION OF CORAL REEFS. [On. XLIX. 
 
 Fig. 147. 
 Genera of Zoophytes most common in coral reefs. 
 
 Astrcea dipsacea, Ehrenb. sp. Syn. Acanthastrata grundis, 
 Milne Edw. & J. Haimes. 
 
 Fig. 148. 
 
 Extremity of branch of Madrepora 
 muricata, Lin. 
 
 Fig. 150. 
 
 Fig. 149- 
 
 Ca i 'iiop/i/i/lia faxtiijiala , Lam. 
 Syn. EusmilM-fastiiimtii, 
 Mime Edw. & J. Haimes. 
 
 Fig. 151. 
 
 Forties clavaria, Lam. 
 
 Oculina hirtella, Lam. 
 
CH. XLIX.] DEPTH AT WHICH COEALS GROW. 583 
 
 immense antiquity, probably several thousand years old, so 
 that Pharaoh may have looked upon these same individuals 
 in the Eed Sea.'* They certainly imply, as he remarks, 
 that the reef on. which they grow has increased at a very 
 slow rate. After collecting more than 100 species, he found 
 none of them covered with parasitic zoophytes, nor any 
 instance of a living coral growing on another living coral. 
 To this repulsive power which they exert whilst living, against 
 all others of their own class, we owe the beautiful symmetry 
 of some large Maeandrinse, and other species which adorn our 
 museums. Yet Balani and Serpulse can attach themselves to 
 the dermal tissues of living corals, and holes are excavated 
 in them by boring mollusks. 
 
 At the island called Taaopoto, in the South Pacific, the 
 anchor of a ship, wrecked about 50 years before, was observed 
 in seven fathoms' water, still preserving its original form, but 
 entirely iiicrusted by coral, f This fact would seem to imply 
 a slow rate of augmentation ; but to form a correct estimate 
 of the average rate must be very difficult, since it must vary 
 not only according to the species of coral, but according to 
 the circumstances under which each species may be placed ; 
 such, for example, as the depth from the surface, the quantity 
 of light, the temperature of the water, its freedom from 
 sand or mud, or the absence or presence of breakers, which 
 is favourable to the growth of some kinds and is fatal to that 
 of others. It should also be observed that the apparent 
 stationary condition of some coral reefs, which according to 
 Beechey have remained for centuries at the same depth under 
 water, may be due to subsidence, the upward growth of the 
 coral having been just sufficient to keep pace with the sinking 
 of the solid foundation on which the zoophytes have built. 
 We shall afterwards see how far this hypothesis is borne out 
 by other evidence in the regions of annular reefs or atolls. 
 
 In one of the Maldive Islands a coral reef, which, within a 
 few years, existed as an islet bearing cocoa-nut trees, was 
 found by Lieutenant Prentice, ' entirely covered with live coral 
 and madrepore.' The natives stated that the islet had been 
 
 * See Ehrenberg's work above cited, f Stuchbury, West of England Jour- 
 
 p. 751. nal, Xo. i. p. 49. 
 
584 FORMATION OF CORAL REEFS. [Cn. XLIX. 
 
 washed away by a change in the currents, and it is clear that 
 a coating of growing coral had been formed in a short time.*" 
 Experiments, also, of Dr. Allan, on the east coast of Mada- 
 gascar, prove the possibility of coral growing to a thickness of 
 three feet in about half a year ; f so that the rate of increase 
 may, under favourable circumstances, be very far from slow. 
 
 It must not be supposed that the calcareous masses termed 
 coral reefs are exclusively the work of zoophytes : a great 
 variety of shells, and, among them, some of the largest and 
 heaviest of known species, contribute to augment the mass. 
 In the South Pacific, great beds of Serpulse, oysters, mussels, 
 Pinnce marince, Chamce (or Tridacnce), and other shells, 
 cover in profusion almost every reef; and on the beach of 
 coral islands are seen the shells of echini and broken frag- 
 ments of crustaceous animals. Large shoals of fish are also 
 discernible through the clear blue water, and their teeth and 
 hard palates cannot fail to be often preserved although their 
 soft cartilaginous bones may decay. 
 
 It was the opinion of the German naturalist Forster, in 
 1780, after his voyage round the world with Captain Cook, 
 that coral animals had the power of building up steep and 
 almost perpendicular walls from great depths in the sea, a 
 notion afterwards adopted by Captain Flinders and others ; 
 but it is now very generally believed that most of these zoo- 
 phytes cannot live in water of great depths. 
 
 Mr. Darwin has come to the conclusion, that those species 
 which are most effective in the construction of reefs, rarely 
 flourish at a greater depth than 20 fathoms, or 120 feet. In 
 some lagoons, however, where the water is but little agitated, 
 there are, according to Kotzebue, beds of living coral in 25 
 fathoms' water, or 150 feet ; but these may perhaps have 
 begun to live in shallower water, and may have been carried 
 downwards by the subsidence of the reef. There are also 
 various species of zoophytes, and among them some which 
 are provided with calcareous as well as horny stems, which 
 live in much deeper water, even in some cases to a depth of 
 1 80 fathoms ; but these do not appear to give origin to stony 
 reefs. 
 
 * Darwin's Coral Reefs, p. 77. t Ibid. p. 78. 
 
CH. XLIX.] 
 
 DEPTH AT WHICH COEALS GROW. 
 
 585 
 
 There is every variety of form in coral reefs, but the most 
 remarkable and numerous in the Pacific consist of circular 
 or oval strips of dry land, enclosing a shallow lake or 
 lagoon of still water, in which zoophytes and mollusca abound. 
 The annular reefs just raise themselves above the level of the 
 sea, and are surrounded by a deep and often unfathomable 
 ocean. 
 
 In the annexed cut (fig. 152), one of these circular islands 
 
 Fig. l-->2. 
 
 
 View of Whitsunday Island. (Capt. Beechey.)* 
 
 is represented, just rising above the waves, covered with the 
 cocoa-nut and other trees, and enclosing within a lagoon of 
 tranquil water. 
 
 The accompanying section will enable the reader to com- 
 prehend the usual form of such islands. (*Fig. 153.) 
 
 Fig. 153. 
 
 Section of a Coral Island. 
 
 n, a. Habitable part of the island, consisting of a strip of coral, enclosing the lagoon. 
 6, b. The lagoon. 
 
 The subjoined cut (fig. 154) exhibits a small part of the 
 section of a coral island on a larger scale. 
 
 Of thirty-two of these coral islands visited by Beechey in 
 his voyage to the Pacific, twenty-nine had lagoons in their 
 
 * Voyage to the Pacific, &c. in 1825-28. 
 
586 FORMATION OF CORAL REEFS. [Cn. XLIX. 
 
 centres. The largest was 30 miles in diameter, and the 
 smallest less than a mile. All were increasing their dimen- 
 sions by the active operations of the lithophytes, which ap- 
 peared to be gradually extending and bringing the immersed 
 
 Fig. 154. 
 
 4* b 
 
 Section of part of a Coral Island. 
 
 a, 6. Habitable part of the island. 
 
 6, V. Slope of the side of the island, plunging at an angle of forty -five to the depth of 
 fifteen hundred feet. 
 
 c, c. Part of the lagoon. 
 
 d, d. Knolls of coral in the lagoon, with overhanging masses of coral resembling the 
 
 capitals of columns. 
 
 parts of their structure to the surface. The scene presented 
 by these annular reefs is equally striking for its singularity 
 and beauty. A strip of land a few hundred yards wide is 
 covered by lofty cocoa-nut trees, above which is the blue 
 vault of heaven. This band of verdure is bounded by a beach 
 of glittering white sand, the outer margin of which is encir- 
 cled with a ring of snow-white breakers, beyond which are 
 the dark heaving waters of the ocean. The inner beach en- 
 closes the still clear water of the lagoon, resting in its greater 
 part on white sand, and when illuminated by a vertical sun, 
 of a most vivid green. * Certain species of zoophytes abound 
 most in the lagoon, others on the exterior margin, where 
 there is a great surf. < The ocean,' says Mr. Darwin, 6 throw- 
 ing its breakers on these outer shores, appears an invincible 
 enemy, yet we see it resisted and even conquered by means 
 which at first seem most weak and inefficient. No periods 
 of repose are granted, and the long swell caused by the steady 
 action of the trade wind never ceases. The breakers exceed 
 in violence those of our temperate regions, and it is impos- 
 sible to behold them without feeling a conviction that* rocks 
 of granite or quartz would ultimately yield and be demolished 
 by such irresistible forces. Yet these low insignificant coral 
 islets stand and are victorious, for here another power, as 
 antagonist to the former, takes part in the contest. The 
 organic forces separate the atoms of carbonate of lime one by 
 
 * Darwin's Journal, &c., p. 540, and new edit., of 1845, p. 453. 
 
CH.XLIX.] REEFS CONVERTED INTO ISLANDS. 587 
 
 one from the foaming- breakers, and unite them into a sym- 
 metrical structure ; myriads of architects are at work night 
 and day, month after month, and we see their soft and gela- 
 tinous bodies through the agency of the vital laws conquering 
 the great mechanical power of the waves of an ocean, which 
 neither the art of man, nor the inanimate works of nature, 
 could successfully resist.' * 
 
 As the coral animals require to be continually immersed in 
 salt water, they cannot raise themselves by their own efforts 
 above the level of the lowest tides. The manner in which 
 the reefs are converted into islands above the level of the sea 
 is thus described by Chamisso, a naturalist who accompanied 
 Kotzebue in his voyages: 'When the reef,' says he, 'is of 
 such a height that it remains almost dry at low water, the 
 corals leave off building. Above this line a continuous mass 
 of solid stone is seen composed of the shells of mollusks and 
 echini, with their broken-off prickles and fragments of coral, 
 united by calcareous sand, produced by the pulverisation of 
 shells. The heat of the sun often penetrates the mass of 
 stone when it is dry, so that it splits in many places, and the 
 force of the waves is thereby enabled to separate and lift 
 blocks of coral, frequently six feet long and three or four in 
 thickness, and throw them upon the reef, by which means 
 the ridge becomes at length so high that it is covered only 
 during some seasons of the year by the spring tides. After 
 this the calcareous sand lies undisturbed, and offers to the 
 seeds of trees and plants cast upon it by the waves a soil upon 
 which they rapidly grow, to overshadow its dazzling white 
 surface. Entire trunks of trees, which are carried by the 
 rivers from other countries and islands, find here, at length, 
 a resting-place after their long wanderings : with these come 
 some small animals, such as insects and lizards, as the first 
 inhabitants. Even before the trees form a wood, the sea- 
 birds nestle here ; stray land-birds take refuge in the bushes ; 
 and, at a much later period, when the work has been long 
 since completed, man appears and builds his hut on the 
 fruitful soil.' f 
 
 * Darwin's Journal, &c., pp. 547, 548, and 2nd edit,, of 1845, p. 460. 
 t Kotzebue's Voy., 1815-18, vol. iii. pp. 331-333. 
 
588 FORMATION OF CORAL REEFS. [Cn. XLIX. 
 
 In the above description the solid stone is stated to consist 
 of shell and coral, united by sand ; but masses of very compact 
 limestone are also found even in the uppermost and newest 
 parts of the reef, such as could only have been produced by 
 chemical precipitation. Professor Agassiz also informs me 
 that his observations on the Florida reefs (which confirm 
 Darwin's theory of atolls to be mentioned in the sequel) 
 have convinced him, that large blocks are loosened, not by 
 shrinkage in the sun's heat, as Chamisso imagined, but by 
 innumerable perforations of lithodomi and other boring tes- 
 tacea. 
 
 The carbonate of lime may have been principally derived 
 from the decomposition of corals and testacea ; for when the 
 animal matter undergoes putrefaction, the calcareous resi- 
 duum must be set free under circumstances very favourable 
 to precipitation, especially when there are other calcareous 
 substances, such as shells and corals, on which it may be 
 deposited. Thus organic bodies may be enclosed in a solid 
 cement, and become portions of rocky masses.* 
 
 The width of the circular strip of dead coral forming the 
 islands explored by Captain Beechey, exceeded in no instance 
 half a mile from the usual wash of the sea to the edge of the 
 lagoon, and, in general, was only about three or four hundred 
 yards. f The depth of the lagoons is various ; in some, entered 
 by Captain Beechey, it was from 20 to 38 fathoms. 
 
 The two other peculiarities which are most characteristic of 
 the annular reef or atoll is first, that the strip of dead coral 
 is invariably highest on the windward side, and secondly, 
 that there is very generally an opening at some point in the 
 reef affording a narrow passage, often of considerable depth, 
 from the sea into the lagoon. 
 
 Maldive and Laccadive Isles. The chain of reefs and 
 islets called the Maldives (see fig. 155), situated in the 
 Indian Ocean, to the south-west of Malabar, forms a chain 
 470 geographical miles in length, running due north 
 and south, with an average breadth of about 50 miles. It 
 
 * Stutchbury, West of Eng. Journ., Journ. Geol. Soc., Nov. 1864, p. 360. 
 No. i. p. 50, and P. M. Duncan, Quart. f Captain Beechey, part i. p. 188. 
 
CH. XLIX.] CIRCULAR FORM OF CORAL ISLANDS. 
 
 589 
 
 %*r 
 
 !.. .>-**. 
 $'"<& 
 
 *-* 
 
 %.$iiff^ 
 
 A?^ 
 
 is composed throughout of a series of circular assemblages 
 of islets, all formed of coral, the larger groups being from 
 40 to 90 miles in their longest diameter. Captain Hors- 
 burgh, whose chart of these islands is Fig. 155. 
 
 subjoined, states, that outside of each 
 
 * 
 
 circle or atoll, as it is termed, there are 
 coral reefs sometimes extending to the 
 distance of two or three miles, beyond 
 which there are no soundings at im- . 
 meiise depths. But in the centre of 
 each atoll there is a lagoon from 15 
 to 49 fathoms deep. In the chan- 
 nels between the atolls no sound- - 
 ings can usually be obtained at the 
 depth of 150 or even 250 fathoms, but 
 during Captain Moresby's surrey, 
 soundings were struck at 150 and 200 
 fathoms, the only instances as yet 
 known of the bottom having been 
 reached, either in the Indian or Pacific 
 oceans, in a space intervening between 
 two separate and well characterised y 
 atolls. 
 
 The singularity in the form of the 
 atolls of this archipelago consists in 
 their being made up, not of one contin- 
 uous circular reef, but of a ring of small 
 coral islets sometimes more than a 
 hundred in number, each of which is a 
 miniature atoll in itself ; in other words, 
 a ring-shaped strip of coral surround- - 
 ing a lagoon of salt water. To account 
 for the origin of these, Mr. Darwin 
 supposes the larger annular reef to have 
 been broken up into a number of frag- 
 ments, each of which acquired its pecu- 
 liar configurations under the influence 
 of causes similar to those to which the 
 structure of the parent atoll has been due. Many of the 
 
 f a Tialf dvyrt 
 ChtinneL. 
 
 Equatorial Channel 
 
590 FOKMATION OF COEAL EEEFS. [Cn. XLIX. 
 
 minor rings are no less than three, and even five miles in 
 diameter, and some are situated in the midst of the principal 
 lagoon ; but this happens only in cases where the sea can 
 enter freely through breaches in the outer or marginal reef. 
 
 The rocks of the Maldives are composed of sandstone 
 formed of broken shells and corals, such as may be obtained 
 in a loose state from the beach, and which is seen when 
 exposed for a few days to the air to become hardened. 
 The sandstone is sometimes observed to be an aggregate of 
 broken shells, corals, pieces of wood, and shells of the cocoa- 
 nut.'* 
 
 The Laccadive Islands run in the same line with the 
 Maldives, on the north, as do the islands of the Chagos 
 Archipelago, on the south ; so that these may be continua- 
 tions of the same chain of submerged mountains, crested in 
 a similar manner by coral limestones. 
 
 Origin of the circular form not volcanic. The circular 
 and oval shape of so many reefs, each having a lagoon in the 
 centre, and being surrounded on all sides by a deep ocean, 
 naturally suggested the idea that they were nothing more 
 than the crests of submarine volcanic craters overgrown by 
 coral : and this theory I myself advocated in the earlier 
 editions of this work. Although I am now about to show 
 that it must be abandoned, it may still be instructive to point 
 out the grounds on which it was formerly embraced. In the 
 first place, it had been remarked that there were many active 
 volcanos in the coral region of the Pacific, and that in some 
 places, as in Gambier's group, rocks composed of porous lava 
 rise up in a lagoon bordered by a circular reef, just as the 
 two cones of eruption called the Kaimenis have made their 
 appearance in the times of history within the circular gulf 
 of Santorin.f It was also observed that as in S. Shetland, 
 Barren Island, and others of volcanic origin, there is one 
 narrow breach in the walls of the outer cone by which ships 
 may enter a circular gulf, so in like manner there is often a 
 single deep passage leading into the lagoon of a coral island, 
 the lagoon itself seeming to represent the hollow or gulf 
 
 * Captain Moresby on the Maldives, ii. p. 400. 
 Journ. Roy. G-eograph. Soc., vol. v. part f See above, p. 69. 
 
CH. XLIX.] CIRCULAR FORM OF CORAL ISLANDS. 591 
 
 just as the ring of dry coral recalls to our minds the riui 
 of a volcanic crater. More lately, indeed, Mr. Darwin has 
 shown that the numerous volcanic craters of the Galapagos 
 Archipelago in the Pacific have all of them their southern 
 sides the lowest, or in many cases quite broken down, so that 
 if they were submerged and incrusted with coral, they would 
 resemble true atolls in shape.* 
 
 Another argument which I adduced when formerly de- 
 fending this doctrine was derived from Ehrenberg's statement, 
 that some banks of coral in the Red Sea were square, while 
 many others were ribbon-like strips, with flat tops, and with- 
 out lagoons. Since, therefore, all the genera and many of 
 the species of zoophytes in the Red Sea agreed with those 
 which elsewhere construct lagoon islands, it followed that the 
 stone-making zoophytes are not guided by their own instinct 
 in the formation of annular reefs, but that this peculiar shape 
 and the position of such reefs in the midst of a deep ocean 
 must depend on the outline of the submarine bottom, which 
 resembles nothing else in nature but the crater of a loffcy sub- 
 merged volcanic cone. The enormous size, it is true, of some 
 atolls made it necessary for me to ascribe to the craters of 
 many submarine volcanos a magnitude which was startling, 
 and which had often been appealed to as a serious objection 
 to the volcanic theory. That so many of them were of the 
 same height, or just level with the water, did not present a 
 difficulty so long as we remained ignorant of the fact that the 
 reef-building species do not grow at greater depths than 
 25 fathoms. 
 
 May be explained by subsidence. Mr. Darwin, after examiii- 
 ning a variety of coral formations in different parts of the 
 globe, was induced to reject the opinion that their shape 
 represented the form of the original bottom. Instead of 
 admitting that the ring of dead coral rested on a circular or 
 oval ridge of rock, or that the lagoon corresponded to a pre- 
 existing cavity, he advanced a new opinion, which must, at 
 first sight, seem paradoxical in the extreme : namely, that 
 the lagoon is precisely in the place once occupied by the 
 
 * Darwin, Volcanic Islands, p. 113. 
 
592 FORMATION OF CORAL REEFS. [Cn. XLIX. 
 
 highest part of a mountainous island, or, in other cases, by 
 the top of a shoal. 
 
 The following is a brief sketch of the facts and arguments 
 in favour of this new view: Besides those rings of dry 
 coral which enclose lagoons, there are others having a similar 
 form and structure which encircle lofty islands. Of the latter 
 kind is Yanikoro (see Map, fig. 59, p. 586), celebrated on 
 account of the shipwreck of La Peyrouse, where the coral 
 reef runs at the distance of two or three miles from the shore, 
 the channel between it and the land having a general depth 
 of between 200 and 300 feet. This channel, therefore, is 
 analogous to a lagoon, but with an island standing in the 
 middle like a picture in its frame. In like manner in Tahiti 
 we see a mountainous land, with everywhere round its mar- 
 gin a lake or zone of smooth salt water, separated from the 
 ocean by an encircling reef of coral, on which a line of 
 breakers is always foaming. So also New Caledonia, a long 
 narrow island east of New Holland, composed partly of 
 granite and partly of triassic sandstone, is surrounded by a 
 reef 400 miles long. This reef encompasses not only the 
 island itself, but a ridge of rocks which is prolonged in the 
 same direction beneath the sea. No one, therefore, will 
 contend for a moment that in this case the corals are based 
 upon the rim of a volcanic crater, in the middle of which 
 stands a mountain or island of granite and sandstone. 
 
 The great barrier reef, already mentioned as running paral- 
 lel to the north-east coast of Australia for nearly 1,000 miles, 
 is another most remarkable example of a long strip of coral 
 running parallel to a coast. Its distance from the main- 
 land varies from 20 to 70 miles, and the depth of the 
 great arm of the sea thus enclosed is usually between 10 
 and 20 fathoms, but towards one end from 40 to 60. This 
 great reef would extend much farther, according to Mr. 
 Jukes, if the growth of coral were not prevented off the shores 
 of New Guinea by a muddy bottom, caused by rivers charged 
 with sediment which flow from the southern coast of that 
 
 great island.*" 
 
 Quart Joiirn. Geol. Soc. 4, xciii. 
 
CH. XLIX.] 
 
 OKIGIN OF THEIE FORM. 
 
 593 
 
 Two classes of reefs, therefore, have now been considered ; 
 first, the atoll, and, secondly, the encircling and barrier reef, 
 both agreeing perfectly in structure, and the sole difference 
 lying in the absence in the case of the atoll of all land, and 
 in the others the presence of land bounded either by an en- 
 circling or a barrier reef. But there is still a third class of 
 reefs, called by Mr. Darwin ' fringing reefs,' which approach 
 much nearer the land than those of the encircling and barrier 
 class, and which indeed so nearly touched the coast as to 
 leave nothing in the intervening space resembling a lagoon. 
 6 That these reefs are not attached quite close to the shore 
 appears to be the result of two causes ; first, that the water 
 immediately adjoining the beach is rendered turbid by the 
 surf, and therefore injurious to all zoophytes ; and, secondly, 
 that the larger and efficient kinds only flourish on the outer 
 edge amidst the breakers of the open sea.'* 
 
 It will at once be conceded that there is so much analogy 
 between the form and position of the strip of coral in the 
 
 Supposed section of an island with an encircling reef of coral. 
 
 A. The island. 
 
 6, c. Highest points of the encircling reef between which and the coast is seen a space 
 occupied by still water. 
 
 atoll, and in the encircling and barrier reef, that no explana- 
 tion can be satisfactory which does not include the whole. 
 If we turn, in the first place, to the encircling and barrier 
 reefs, and endeavour to explain how the zoophytes could 
 have found a bottom on which to begin to build, we are met 
 at once with a great difficulty. It is a general fact, long since 
 remarked by Dampier, that high land and deep seas go 
 together. In other words, steep mountains coming down 
 
 * Darwin's Journ., p. 557, 2nd edit. chap. 20, and Coral Islands, chapters 
 1, 2, 3. 
 
 VOL. II. Q Q 
 
594 FORMATION OF CORAL REEFS. [Cn. XLIX. 
 
 abruptly to the sea-shore are generally continued with the 
 same slope beneath the water. But where the reef, as at 
 b c (fig. 156), is distant several miles from a steep coast, a line 
 drawn perpendicularly downwards from its outer edges & c to 
 the fundamental rock d e, must descend to a depth exceeding 
 by several thousand feet the limits at which the efficient stone- 
 building corals can exist, for we have seen that they cease 
 to grow in water which is more than 120 feet deep. That 
 the original rock immediately beneath the points b c is ac- 
 tually as far from the surface d e, is not merely inferred from 
 Dampier's rule, but confirmed by the fact, that, immediately 
 outside the reef, soundings are either not met with at all, or 
 only at enormous depths. In short, the ocean is as deep as 
 might have been anticipated in the neighbourhood of a bold 
 coast ; and it is obviously the presence of the coral alone 
 which has given rise to the anomalous existence of shallow 
 water on the reef and between it and the land. 
 
 After studying in minute detail all the phenomena above 
 described, Mr. Darwin has offered in explanation a theory 
 now very generally adopted. The coral-forming polypi, he 
 states, begin to build in water of a moderate depth, and, while 
 they are yet at work, the bottom of the sea subsides gradu- 
 ally, so that the foundation of their edifice is carried down - 
 wards at the same time that they are raising the superstruc- 
 ture. If, therefore, the rate of subsidence be not too rapid, 
 the growing coral will continue to build up to the surface ; 
 the mass always gaining in height above its original base, 
 but remaining in other respects in the same position. Not 
 so with the land : each inch lost is irreclaimably gone ; as it 
 sinks the water gains foot by foot 011 the shore, till in many 
 cases the highest peak of the original island disappears. 
 What was before land is then occupied by the lagoon, the 
 position of the encircling coral remaining unaltered, with the 
 exception of a slight contraction of its dimensions. 
 
 In this manner are encircling reefs and atolls produced ; 
 and in confirmation of his views Mr. Darwin has pointed out 
 examples which illustrate every intermediate state, from that 
 of lofty islands such as Otaheite, encircled by coral, to that 
 of Gambier's group, where a few peaks only of land rise out 
 
CH. XLIX.] 
 
 ORIGIN OF THEIR FORM. 
 
 505 
 
 of a lagoon, and, lastly, to the perfect atoll, having a lagoon 
 several hundred feet deep, surrounded by a reef rising deeply 
 from an unfathomed ocean. 
 
 If we embrace these views, it is clear, that in regions of 
 growing coral a similar subsidence must give rise to barrier 
 reefs along the shores of a continent. Thus suppose A 
 (fig. 157) to represent the north-eas tportion of Australia, and 
 b c the ancient level of the sea, when the coral reef d was 
 formed. If the land sink so that it is submerged more and 
 more, the sea must at length stand at the level e /, the reef 
 in the meantime having been enlarged and raised to the 
 
 Fig. 157 
 
 point g. The distance between the shore /, and the barrier 
 reef g, is now much greater than originally between th<? 
 shore c and the reef d, and the longer the subsidence con- 
 tinues the farther will the coast of the mainland recede. 
 
 When the first edition of this work appeared in 1831, 
 several years before Mr. Darwin had investigated the facts 
 on which his theory is founded, I had come to the opinion 
 that the land was subsiding at the bottom of those parts of 
 the Pacific where atolls are numerous, although I failed to 
 perceive that such a subsidence, if conceded, would equally 
 solve the enigma as to the form both of annular and barrier 
 reefs. 
 
 I shall cite the passage referred to, as published by me in 
 1831 : ' It is a remarkable circumstance that there should 
 be so vast an area in Eastern Oceanica, studded with 
 minute islands, without one single spot where there is a 
 wider extent of land than belongs to such islands as Otaheite, 
 Owhyhee, and a few others, which either have been or are 
 still the seats of active volcanos. If an equilibrium only 
 were maintained between the upheaving and depressing force 
 of earthquakes, large islands would very soon be formed in 
 the Pacific ; for, in that case, the growth of limestone, the 
 
 Q Q 2 
 
596 FORMATION OF CORAL REEFS. [On. XLIX. 
 
 flowing of lava, and the ejection of volcanic ashes, would 
 combine with the upheaving force to form new land. 
 
 ' Suppose a shoal, 600 miles in length, to sink 15 feet, 
 and then to remain unmoved for a thousand years ; during 
 that interval the growing coral may again approach the 
 surface. Then let the mass be fe-elevated 15 feet, so that 
 the original reef is restored to its former position : in this 
 case, the new coral formed since the first subsidence will 
 constitute an island 600 miles long. An analogous result 
 would have occurred if a lava-current 15 feet thick had 
 overflowed the submerged reef. The absence, therefore, of 
 more extensive tracts of land in the Pacific, seems to show 
 that the amount of subsidence by earthquakes exceeds, in 
 that quarter of the globe, at present, the elevation due to the 
 same cause.' * 
 
 Another proof also of subsidence derived from the struc- 
 ture of atolls, was pointed out by me in the following 
 passage in all former editions. ' The low coral islands of 
 the Pacific,' says Captain Beechey, c follow one general rule 
 in having their windward side higher and more perfect than 
 the other. At Gambier and Matilda Islands this inequality 
 is very conspicuous, the weather side of both being wooded, 
 and of the former inhabited, while the other sides are from 
 20 to 30 feet under water ; where, however, they may be 
 perceived to be equally narrow and well defined. It is on 
 the leeward side also that the entrances into the lagoons 
 occur ; and although they may sometimes be situated on a 
 side that runs in the direction of the wind, as at Bow 
 Island, yet there are none to windward.' These observations 
 of Captain Beechey accord with those which Captain Hors- 
 burgh and other hydrographers have made in regard to the 
 coral islands of other seas. From this fortunate circum- 
 stance ships can enter and sail out with ease ; whereas if 
 the narrow inlets were to windward, vessels which once 
 entered might not succeed for months in making their way 
 out again. The well-known security of many of these 
 harbours depends entirely on this fortunate peculiarity in 
 their structure. 
 
 * See Principles of Geology, 1st. edit., vol. ii. p. 296. 
 
CH. XLIX.] ORIGIN OF THEIR FORM. 5 ( J7 
 
 e In what manner is this singular conformation to be ac- 
 counted for ? The action of the waves is seen to be the 
 cause of the superior elevation of some reefs on their wind- 
 ward sides, where sand and large masses of coral rock are 
 thrown up by the breakers ; but there is a variety of cases 
 where this cause alone is inadequate to solve the problem ; 
 for reefs submerged at considerable depths, where the move- 
 ments of the sea cannot exert much power, have, neverthe- 
 less, the same conformation, the leeward being much lower 
 than the windward side.* 
 
 c I am informed by Captain King, that, on examining the 
 reefs called Rowley Shoals, which lie off the north-west 
 coast of Australia, where the east and west monsoons prevail 
 alternately, he found the open side of one crescent-shaped 
 reef, the Imperieuse, turned to the east, and of another, the 
 Mermaid, turned to the west ; while a third oval reef, of the 
 same group, was entirely submerged. This want of con- 
 formity is exactly what we should expect, where the winds 
 vary periodically. 
 
 6 It seems impossible to refer the phenomenon now under 
 consideration to any original uniformity in the configuration 
 of submarine volcanos, on the summits of which we may 
 suppose the coral reefs to grow; for although it is very 
 common for craters to be broken down on one side only, we 
 cannot imagine any cause that should breach them all in the 
 same direction. But the difficulty will, perhaps, be removed, 
 if we call in another part of the volcanic agency subsidence 
 by earthquakes. Suppose the windward barrier to have been 
 raised by the mechanical action of the waves to the height 
 of 2 or 3 yards above the wall on the leeward side, and 
 then the whole island to sink down a few fathoms, the ap- 
 pearances described would then be presented by the sub- 
 merged reef. A repetition of such operations, by the alter- 
 nate elevation and depression of the same mass (an hypothesis 
 strictly conformable to analogy), might produce still greater 
 inequality in the two sides, especially as the violent efflux 
 of the tide has probably a strong tendency to check the 
 
 * Voyage to the Pacific, &c., p. 189. 
 
5U8 FORMATION OF CORAL REEFS. [Cn. XLIX. 
 
 accumulation of the more tender corals on the leeward reef; 
 while the action of the breakers contributes to raise the 
 windward barrier.' * 
 
 Previously to niy adverting to the signs above enumerated 
 of a downward movement in the bed of the ocean, Dr. 
 Macculloch, Captain Beechey, and many other writers had 
 shown that masses of recent coral had been laid dry at 
 various heights above the sea-level, both in the Red Sea, the 
 islands of the Pacific, and in the East and West Indies. 
 After describing thirty-two coral islands in the Pacific, 
 Captain Beechey mentioned that they were all formed of 
 living coral except one, which although of coral formation, 
 was raised about 70 or 80 feet above the level of the sea, 
 and was encompassed by a reef of living coral. It is called 
 Elizabeth or Henderson's Island, and is 5 miles in length 
 by 1 in breadth. It has a flat surface, and, on all sides, 
 except the north, is bounded by perpendicular cliffs above 
 50 feet high, composed entirely of dead coral, more or less 
 porous, honeycombed at the surface, and hardening into a 
 compact calcareous mass, which possesses the fracture of 
 secondary limestone, and has a species of millepore inter- 
 Fig. 158. 
 
 Elizabeth or Henderson's Island. 
 
 spersed through it. These cliffs are considerably undermined 
 by the action of the waves, and some of them appear on the 
 eve of precipitating their superincumbent weight into the 
 sea. Those which are less injured in this way present no 
 alternate ridges or indication of the different levels which 
 the sea might have occupied at different periods ; but a 
 smooth surface, as if the island, which has probably been 
 raised by volcanic agency, had been forced up by one great 
 subterraneous coiivulsion.f At the distance of a few hun- 
 dred yards from this island, no bottom could be gained with 
 200 fathoms of line. 
 
 It will be seen, from the annexed sketch, communicated to 
 
 * See Principles of Geol., 1st. edit., 1832, vol. ii. p. 293. 
 t Beech ey's Voyage to_the Pacific, &c., p. 46. 
 
3IK. DARWIN'S THEOEY OF SUBSIDENCE. 590 
 
 me by Lieutenant Smith, of the Blossom, that the trees 
 (.nine down to the beach towards the centre of the island, 
 where there is a break in the cliffs resembling at first sight 
 the openings which usually lead into lagoons ; but the trees 
 stand on a steep slope, and no hollow of an ancient lagoon 
 was perceived. Beechey also remarks, that the surface of 
 Henderson's Island is flat, and that in Queen Charlotte's 
 Island, one of the same group, but under water, there was 
 no lagoon, the coral having grown up everywhere to one 
 level. The probable cause of this obliteration of the central 
 basin or lagoon will be considered in the sequel. 
 
 That the bed of the Pacific and Indian oceans, where 
 atolls are frequent, must have been sinking for ages, might 
 be inferred, says Mr. Darwin, from simply reflecting on two 
 facts ; first, that the efficient coral-building zoophytes do not 
 flourish in the ocean at a greater depth than 120 feet ; and, 
 secondly, that there are spaces occupying areas of many 
 hundred thousand square miles, where all the islands consist 
 of coral, and yet none of which rise to a greater height than 
 may be accounted for by the action of the winds and waves 
 on broken and triturated coral. Were we to take for granted 
 that the floor of the ocean had remained stationary from the 
 time when the coral began to grow, we should be compelled 
 to assume that an incredible number of submarine moun- 
 tains of vast height (for the ocean is always deep, and often 
 unfathomable between the different atolls,) had all come to 
 within 120 feet of the surface, and yet no one mountain had 
 risen above water. But no sooner do we admit the theory of 
 subsidence than this great difficulty vanishes. However 
 varied may have been the altitude of different islands, or the 
 separate peaks of particular mountain-chains, all may have 
 been reduced to one uniform level by the gradual submer- 
 gence of the loftiest points and the additions made to the 
 calcareous cappings of the less elevated summits as they 
 subsided to great depths. 
 
 Openings into the lagoons. In the general description of 
 atolls and encircling reefs, it was mentioned that there is 
 almost always a deep narrow passage opening into the 
 lagoon, or into the still water between the reef and the 
 
600 FOKMATION OF COEAL EEEFS. [Cn. XLIX. 
 
 shore, which, is kept open by the efflux of the sea as the 
 tide goes down. 
 
 The origin of this channel must, according to the theory 
 of subsidence before explained, be traced back to causes 
 which were in action during the existence of the encircling 
 reef, and when an island or mountain top rose within it, for 
 such a reef precedes the atoll in the order of formation. 
 JSTow in those islands in the Pacific, which are large enough 
 to feed small rivers, there is generally an opening or channel 
 in the surrounding coral reef at the point where the stream 
 of fresh water enters the sea. The depth of these channels 
 rarely exceeds 25 feet; and they may be attributed, says 
 Captain Beechey, to the aversion of the lithophytes to fresh 
 water, and to the probable absence of the mineral matter of 
 which they construct their habitations.* 
 
 Mr. Darwin, however, has shown, that mud at the bottom 
 of river-courses is far more influential than the freshness of 
 the water in preventing the growth of the polypi, for the 
 walls which enclose the openings are perpendicular, and do 
 not slant off gradually, as would be the case, if the nature 
 of the element presented the only obstacle to the increase of 
 the coral-building animals. 
 
 When a breach has thus been made in the reef, it will be 
 prevented from closing up by the efflux of the sea at low 
 tides ; for it is sufficient that a reef should rise a few feet 
 above low-water mark to cause the waters to collect in the 
 lagoon at high tide, and when the sea falls, to rush out at 
 one or more points where the reef happens to be lowest or 
 weakest. This event is strictly analogous to that witnessed 
 in our estuaries where a body of salt water accumulated 
 during the flow issues with great velocity at the ebb of the 
 tide, and scours out or keeps open a deep passage through 
 the bar, which is almost always formed at the mouth of a 
 river. At first there are probably many openings, but the 
 growth of the coral tends to obstruct all those which do not 
 serve as the principal channels of discharge ; so that their 
 number is gradually reduced to a few, and often finally to 
 
 * Voyage to the Pacific, &c., p. 194. 
 
CH. XLIX.] SIZE OF ATOLLS AND BARRIER REEFS. 601 
 
 one. The fact observed universally, that the principal opening 
 fronts a considerable valley in the encircled island, between 
 the shores of which and the outer reef there is often deep 
 water, scarcely leaves any doubt as to the real origin of the 
 channel in all those countless atolls where the nucleus of 
 land has vanished. 
 
 Size of atolls and barrier reefs. In regard to the dimen- 
 sions of atolls, it was stated that some of the smallest ob- 
 served by Beechey in the Pacific were only a mile in diameter. 
 If their external slope under water equals upon an average 
 an angle of 45, then would such an atoll at the depth of 
 half a mile, or 2,640 feet, have a diameter of two miles. 
 Hence it would appear that there must be a tendency in 
 every atoll to grow smaller, except in those cases where 
 oscillations of level enlarge the base on which the coral 
 grows by throwing down a talus of detrital matter all round 
 the original cone of limestone. 
 
 Bow Island is described by Captain Beechey as 70 miles in 
 circumference, and 30 in its greatest diameter, but we have 
 seen that some of the Maldives are much larger. 
 
 As the shore of an island or continent which is subsiding 
 will recede from a coral reef at a slow or rapid rate according 
 as the surface of the land has a steep or gentle slope, we 
 cannot measure the thickness of the coral by its distance 
 from the coast ; yet, as a general rule, those reefs which are 
 farthest from the land imply the greatest amount of sub- 
 sidence. We learn from Minders, that the barrier reef of 
 north-eastern Australia is in some places 70 miles from the 
 mainland, and it should seem that a calcareous formation is 
 there in progress 1,000 miles long from north to south, with 
 a breadth varying from 20 to 70 miles. It may not, indeed, 
 be continuous over this vast area, for doubtless innumerable 
 islands have been submerged one after another between the 
 reef and mainland, like some which still remain, as, for 
 example, Murray's Islands, lat. 9 54' S. We are told that 
 some parts of the gulf enclosed within the barrier are 400 
 feet deep, so that the efficient rock-building corals cannot be 
 growing there, and in other parts of it islands appear en- 
 circled by reefs. 
 
602 FORMATION OF CORAL REEFS. [Cn.XLIX.' 
 
 It will follow as one of the consequences of the theory 
 already explained that, provided the bottom of the sea does 
 not sink too fast to allow the zoophytes to build upwards 
 at the same pace, the thickness of coral will be great in 
 proportion to the rapidity of subsidence, so that if one area 
 sinks 2 feet while another sinks 1, the mass of coral in the 
 first area will be double that in the second. But the down- 
 ward movement must in general have been very slow and 
 uniform, or, where intermittent, must have consisted of a 
 great number of depressions, each of slight amount, other- 
 wise the bottom of the sea would have been carried down 
 faster than the corals could build upwards, and the island 
 or continent would be permanently submerged, having 
 reached a depth of 120 or 150 feet, at which the effective 
 reef-constructing zoophytes cease to live. If, then, the sub- 
 sidence required to account for all the existing atolls must 
 have amounted to 3,000 or 4,000 feet, or even sometimes 
 more, we are brought to the conclusion that there has been 
 a slow and gradual sinking to this enormous extent. Such 
 an inference is perfectly in harmony with views which the 
 grand scale of denudation, everywhere observable in the 
 older rocks, has led geologists to adopt in reference to up- 
 ward movements. They must also have been gradual and 
 continuous throughout indefinite ages to allow the waves and 
 currents of the ocean to operate with adequate power. 
 
 The map constructed by Mr. Darwin to display at one 
 view the geographical position of all the coral reefs through- 
 out the globe is of the highest geological interest, leading 
 to splendid generalisations, when we have once embraced 
 the theory that all atolls and barrier reefs indicate recent 
 subsidence, while the presence of fringing reefs proves 
 the land to] be stationary or rising. These two classes of 
 coral formations are depicted by different colours; and 
 one of the striking facts brought to light by the same 
 classification, of coral formations is the absence of active 
 volcanos in areas of subsidence, and their frequent presence 
 in the areas of elevation. The only supposed exception to 
 this remarkable coincidence at the time when Mr. Darwin 
 wrote, in 1842, was the volcano of Torres Strait, at the 
 
CH. XLIX.] MR. DARWIN'S MAP OF CORAL REEFS. 603 
 
 northern point of Australia, placed on the borders of an area 
 of subsidence ; but it has been since proved that this volcano 
 has no existence. 
 
 We see, therefore, an evident connection, first, between the 
 bursting forth every now and then of volcanic matter through 
 rents and fissures, and the expansion or forcing outwards of 
 the earth's crust, and, secondly, between a dormant and less 
 energetic development of subterranean heat, and an amount 
 of subsidence sufficiently great to cause mountains to dis- 
 appear over the broad face of the ocean, leaving only small 
 and scattered lagoon islands, or group of atolls, to indicate 
 the spots where those mountains once stood. 
 
 On a review of the differently-coloured reefs on the map 
 alluded to, it will be seen that there are large spaces in 
 which upheaval, and others in which depression prevails, 
 and these are placed alternately, while there are a few 
 smaller areas where movements of oscillation occur. Thus 
 if we commence with the western shores of South America, 
 between the summit of the Andes and the Pacific (a region 
 of earthquakes and active volcanos), we find signs of recent 
 elevation, not attested by coral formations, which are want- 
 ing there, but by upraised banks of marine shells. Then 
 proceeding westward, we traverse a deep ocean without 
 islands, until we come to a band of atolls and encircled 
 islands, including the Dangerous and Society archipelagos, 
 and constituting an area of subsidence more than 4,000 miles 
 long and 600 broad. Still farther, in the same direction, we 
 reach the chain of islands to which the New Hebrides, 
 Salomon, and New Ireland belong, where fringing reefs and 
 masses of elevated coral indicate another area of upheaval. 
 Again, to the westward of the New Hebrides we meet with 
 the encircling reef of New Caledonia and the great Australian 
 barrier, implying a second area of subsidence. 
 
 The only objection deserving attention which has hitherto 
 been advanced against the theory of atolls, as before ex- 
 plained (p. 591), is that proposed by Mr. Maclaren.* ' On the 
 outside,' he observes, ' of coral reefs very highly inclined, no 
 
 * Scotsman, Nov. 1842, and Jameson's Edin. Journ. of Science, 1843. 
 
604 FOKMATION OF COEAL KEEFS. [Cn. XLIX. 
 
 bottom is sometimes found with a line of 2,000 or 3,000 feet, 
 and this is by no means a rare case. It follows that the reef 
 ought to ha,ve this thickness ; and Mr. Darwin's diagrams 
 show that he understood it so. Now, if such masses of coral 
 exist under the sea, they ought somewhere to be found on 
 terra firma ; for there is evidence that all the lands yet visited 
 by geologists have been at one time submerged. But neither 
 in the great volcanic chain, extending from Sumatra to Japan, 
 nor in the West Indies, nor in any other region yet explored, 
 has a bed or formation of coral even 500 feet thick been dis- 
 covered, so far as we know.' 
 
 "When considering the objection, it is evident that the 
 first question we have to deal with is, whether geologists have 
 not already discovered calcareous masses of the required 
 thickness and structure, or precisely such as the upheaval of 
 atolls might be expected to expose to view ? We are called 
 upon, in short, to make up our minds both as to the internal 
 composition of the rocks that must result from the growth of 
 corals, whether in lagoon islands or barrier reefs, and the 
 external shape which the reefs would retain when upraised 
 gradually to a vast height, a task by no means so easy as 
 some may imagine. If the reader has pictured to himself 
 large masses of entire corals, piled one upon the other, for a 
 thickness of several thousand feet, he unquestionably mistakes 
 altogether the nature of the accumulations now in progress. 
 In the first place, the strata at present forming very exten- 
 sively over the bottom of the ocean, within such barrier reefs 
 as those of Australia and New Caledonia, are known to consist 
 chiefly of horizontal layers of calcareous sediment, while here 
 and there an intermixture must occur of the detritus of 
 granitic and other rocks brought down by rivers from the 
 adjoining lands, or washed from sea-cliffs by the waves and 
 currents. Secondly, in regard to atolls, the stone-making 
 polypifers grow most luxuriantly on the outer edge of the 
 island, to a thickness of a few feet only. Beyond this margin 
 broken pieces of coral and calcareous sand are strewed by the 
 breakers over a steep seaward slope, and as the subsidence 
 continues the next coating of live coral does not grow ver- 
 tically over the first layer, but on a narrow annular space 
 
CH. XLIX.] THE THEORY OF SUBSIDENCE CONSIDERED. 605 
 
 within it, the reef, as was before stated (p. 593), constantly 
 contracting its dimensions as it sinks. Thirdly, within the 
 lagoon the accumulation of calcareous matter is chiefly sedi- 
 mentary, a kind of chalky mud derived from the decay of the 
 softer corallines, with a mixture of calcareous sand swept by 
 the winds and waves from the surrounding circular reef. 
 Here and there, but only in partial clumps, are found living 
 corals, which grow in the middle of the lagoon, and mixed 
 with these and with fine mud and sand, a great variety of 
 shells, and fragments of testacea and echinoderms. 
 
 We owe to Lieutenant Nelson the discovery that in the Ber- 
 mudas the calcareous mud resulting from the decomposition 
 of the softer corallines is absolutely undistinguishable when 
 dried from the ordinary white chalk of Europe,* and this mud 
 is carried to great distances by currents, and spread far and 
 wide over the floor of the ocean. We also have opportunities 
 of seeing in upraised atolls, such as Elizabeth Island, Tonga, 
 and Hapai, which rise above the level of the sea to heights 
 varying from 10 to 80 feet, that the rocks of which they 
 consist do not differ in structure or in the state of preserva- 
 tion of their included zoophytes and shells from some of the 
 oldest limestones known to the geologist. Captain Beechey 
 remarks that the dead coral in Elizabeth's Island is ' more or 
 less porous and honeycombed at the surface, and hardening 
 into a compact rock which has the fracture of secondary lime- 
 stone.'^ 
 
 The island of Pulo Nias, off Sumatra, which is about 3,000 
 feet high, is described by Dr. Jack as being overspread by 
 coral and large shells of the Chama (Tridacna) gigas, which 
 rest on quartzose and arenaceous rocks, at various levels from 
 the sea-coast to the summit of the highest hills. 
 
 The cliffs of the island of Timor in the Indian Ocean are 
 composed, says Mr. Jukes, of a raised coral reef abounding 
 in Astrcea, Mceandrina, and Porites, with shells of Strombiis, 
 Conus, Nerita, Area, Pecten, Venus, and Lucina. On a ledge 
 about 150 feet above the sea, a Tridacna (or large clam shell), 
 two feet across, was found bedded in the rock with closed 
 
 * Trans. Geol. Soc. London, 2d series, t Beechey's Voyage, vol. i. p. 45. 
 
 vol. v. 
 
606 FORMATION OF CORAL REEFS. [Cn. XLIX. 
 
 valves, just as tliej are often seen in barrier reefs. This 
 formation in the islands of Sandlewood, Sumbawa, Madura, 
 and Java, where it is exposed in sea cliffs, was found to be 
 from 200 or 300 feet thick, and it is believed to ascend 
 to much greater heights in the interior. It has usually the 
 form of a ' chalk-like ' rock, white when broken, but in the 
 weathered surface turning nearly black.* 
 
 It appears, therefore, premature to assert that there are no 
 recent coral formations uplifted to great heights, for we are 
 only beginning to be acquainted with the geological struc- 
 ture of the rocks of equatorial regions. Some of the upraised 
 islands, such as Elizabeth and Queen Charlotte, in the 
 Pacific, although placed in regions of atolls, are described by 
 Captain Beechey and others as flat-topped, and exhibiting 
 no traces of lagoons. In explanation of the fact, we may 
 presume that, after they had been sinking for ages, the 
 descending movement was relaxed ; and while it was in the 
 course of being converted into an ascending one, the ground 
 remained for a long season almost stationary, in which case 
 the corals within the lagoon would build up to the surface, 
 and reach the level already attained by those on the margin 
 of the reef. In this manner the lagoon would be effaced, and 
 the island acquire a flat summit. 
 
 It may, however, be thought strange that many examples 
 have not been noticed of fringing reefs uplifted above the 
 level of the sea. Mr. Darwin, indeed, cites one instance 
 where the reef preserved, on dry land in the Mauritius, its 
 peculiar moat-like structure ; but they ought, he says, to be 
 of rare occurrence, for in the case of atolls or of barrier or 
 fringing reefs, the characteristic outline must usually be de- 
 stroyed by denudation as soon as a reef begins to rise ; since 
 it is immediately exposed to the action of the breakers, and 
 the large and conspicuous corals on the outer rim of the atoll 
 or barrier are the first to be destroyed and to fall upon the 
 bottom of vertical and undermined cliffs. After slow and 
 continued upheaval a wreck alone can remain of the original 
 reef. If, therefore, says Mr. Darwin, ' at some period as far 
 
 * Paper read to Brit. Assoc. South- that these coral cliffs are now known to 
 ampton, 1846. Dr. Duncan informs me belong to the Tertiary Period. 
 
CH. XLIX.] THE THEORY OF SUBSIDENCE CONSIDERED. GOT 
 
 iii futurity as the secondary rocks are in the past, the bed of 
 the Pacific with, its atolls and barrier reefs should be con- 
 verted into a continent, we may conceive that scarcely any 
 or none of the existing reefs would be preserved, but only 
 widely spread strata of calcareous matter derived from their 
 wear and tear.'* 
 
 When it is urged in support of the objection before stated 
 (p. 603) that the theory of atolls by subsidence implies the 
 accumulation of calcareous formations 2,000 or 3,000 feet 
 thick, it must be conceded that this estimate of the min- 
 imum density of the deposits is by no means exaggerated. 
 On the contrary, when we consider that the space over which 
 atolls are scattered in Polynesia and the Indian oceans may 
 be compared to the whole continent of Asia, we cannot 
 but infer from analogy that the differences in level in so 
 vast an area have amounted, antecedently to subsidence, to 
 5,000 or even a greater number of feet. Whatever was the 
 difference in height between the loftiest and lowest of the 
 original mountains or mountainous islands on which the 
 different atolls are based, that difference must represent the 
 thickness of coral which has now reduced all of them to one 
 level. Flinders, therefore, by no means exaggerated the 
 volume of the limestone, which he conceived to have been 
 the work of coral animals ; he was merely mistaken as to 
 the manner in which they were enabled to build reefs in an 
 unfathomed ocean. 
 
 But is it reasonable to expect, after the waste caused by 
 denudation, that calcareous masses, gradually upheaved in an 
 open sea, should retain such vast thicknesses ? Or may not 
 limestones of the cretaceous and oolitic epochs, which attain 
 in the Alps and Pyrenees a density of 3,000 or 4,000 feet, and 
 are in great part made up of coralline and shelly matter^ 
 present us with a true geological counterpart of the recent 
 coral reefs of equatorial seas ? I am also reminded by Dr. 
 Duncan that the Miocene coral formations of Jamaica are 
 enormously thick. 
 
 Before we attach serious importance to arguments founded 
 
 * Letter to Mr. Maclaren, Scotsman, 1843. 
 
608 FOKMATION OF COKAL KEEFS. [On. XLIX. 
 
 on negative evidence, and opposed to a theory which so 
 admirably explains a great variety of complicated phenomena, 
 we ought to remember that the upheaval to the height of 4,000 
 feet of atolls in which the coralline limestone would be 4,000 
 feet thick, implies, first, a slow subsidence of 4,000 feet, and, 
 secondly, an elevation of the same amount. Even if the re- 
 verse or ascending movement began the instant the down- 
 ward one ceased, we must allow a great lapse of ages for 
 the accomplishment of the whole operation. We must also 
 assume that at the commencement of the period in question, 
 the equatorial regions were as fitted as now for the support 
 of reef-building zoophytes. This postulate would demand 
 the continuance of a complicated variety of conditions 
 throughout a much longer period than they are usually 
 persistent in one place. 
 
 To show the difficulty of speculating on the permanence of 
 the geographical and climatal circumstances requisite for the 
 growth of reef-building corals, we have only to state the fact 
 that there are no reefs in the Atlantic, off the west coast of 
 Africa, nor among the islands of the Gulf of Guinea, nor at 
 St. Helena, Ascension, the Cape Yerds, or St. Paul's. With 
 the exception of Bermuda, there is not a single coral reef in 
 the central expanse of the Atlantic, although in some parts 
 the waves, as at Ascension, are charged to excess with cal- 
 careous matter. The capricious distribution of coral reefs is 
 probably owing to the absence of fit stations for the reef- 
 building polypifers, other organic beings in those regions 
 obtaining in the great struggle for existence a mastery over 
 them. Their absence, in whatever manner it be accounted 
 for, should put us on our guard against expecting upraised 
 reefs at all former geological epochs, similar to those now in 
 progress. 
 
 Lime, whence derived. Dr. Macculloch, in his System of 
 Geology, vol. i. p. 219, expressed himself in favour of the 
 theory of some of the earlier geologists, that all limestones 
 have originated in organised substances. If we examine, he 
 says, the quantity of limestone in the primary strata, it will 
 be found to bear a much smaller proportion to the siliceous 
 and argillaceous rocks than in the secondary ; and this may 
 
CH. XL1X.] LIME WHENCE DERIVED. 609 
 
 have some connection with the rarity of testaceous animals 
 in the ancient ocean. He further infers, that in consequence 
 of the operations of animals, c the quantity of calcareous 
 earth deposited in the form of mud or stone is always in- 
 creasing ; and that as a secondary series far exceeds the pri- 
 mary in this respect, so a third series may hereafter arise from 
 the depths of the sea, which may exceed the last in the pro- 
 portion of its calcareous strata. 5 
 
 The comparative scarcity of carbonate of lime in the oldest 
 rocks insisted upon in the passage here cited, was chiefly 
 deduced from observations on the geology of Scotland, with 
 which Dr. Macculloch was familiar. Of late years our Cana- 
 dian surveyors have taught us that the most ancient series 
 of rocks yet discovered in the earth's crust, the Laurentian, 
 may contain vast formations of limestone, and one of these 
 is characterised by the Eozoon Canadense, a species of fora- 
 minifera. 
 
 If Dr. Macculloch's propositions went no farther than to 
 suggest that every particle of lime that now enters into the 
 crust of the globe may possibly in its turn have been sub- 
 servient to the purposes of life, by entering into the com- 
 position of organised bodies, I should not deem the speculation 
 improbable ; but, when it is hinted that lime may be an 
 animal product combined by the powers of vitality from some 
 simple elements, I can discover no sufficient grounds for such 
 an hypothesis, and many facts militate against it. 
 
 If a large pond be made in almost any soil, and filled with 
 rain water, it will usually become tenanted by testacea ; for 
 carbonate of lime is almost universally diffused in small quan- 
 tities. But if no calcareous matter be supplied by waters 
 flowing from the surrounding high grounds, or by springs, no 
 tufa or shell-marl is formed. The thin shells of one gen- 
 eration of mollusks decompose, so that their elements afford 
 nutriment to the succeeding races ; and it is only where a 
 stream enters a lake, which may introduce a fresh supply of 
 calcareous matter, or where the lake is fed by springs, that 
 shells accumulate and form marl. 
 
 All the lakes in Forfarshire which have produced deposits 
 of shell-marl have been the sites of springs, which still evolve 
 
 VOL. II. R R 
 
610 FORMATION OF COKAL BEEFS. [On. XLIX. 
 
 much, carbonic acid, and a small quantity of carbonate of 
 lime. But there is no marl in Loch Fithie, near Forfar, 
 where there are no springs, although that lake is surrounded 
 by these calcareous deposits, and although, in every other 
 respect, the site is favourable to the accumulation of aquatic 
 testacea. 
 
 We find those Charge which secrete the largest quantity of 
 calcareous matter in their stems to abound near springs im- 
 pregnated with carbonate of lime. We know that, if the 
 common hen be deprived altogether of calcareous nutriment, 
 the shells of her eggs will become of too slight a consistency 
 to protect the contents ; and some birds eat chalk greedily 
 during the breeding season. 
 
 If, on the other hand, we turn to the phenomena of inor- 
 ganic nature, we observe that, in volcanic countries, there is 
 an enormous evolution of carbonic acid, either free, in a 
 gaseous form, or mixed with water ; and the springs of such 
 districts are usually impregnated with carbonate of lime in 
 great abundance. No one who has travelled in Tuscany, 
 through the region of extinct volcanos and its confines, or who 
 has seen the map constructed by Targioni (1827), to show 
 the principal sites of mineral springs, can doubt, for a mo- 
 ment, that if this territory was submerged beneath the sea, 
 it might supply materials for the most extensive coral reefs. 
 The importance of these springs is not to be estimated by the 
 magnitude of the rocks which they have thrown down on the 
 slanting sides of hills, although of these alone large cities 
 might be built, nor by a coating of travertin that covers the 
 soil in some districts for miles in length. The greater part 
 of the calcareous matter passes down in a state of solution 
 to the sea, and in all countries the rivers which flow from 
 chalk and other marly and calcareous rocks carry down vast 
 quantities of lime into the ocean. Lime is also one of the 
 component parts of augite and other volcanic and hypogene 
 minerals, and when these decompose it is set free, and may 
 then find its way in a state of solution to the sea. 
 
 The lime, therefore, contained generally in sea-water, and 
 secreted so plentifully by the testacea and corals of the 
 Pacific, may have been derived either from springs rising up 
 
Cn. XLIX.] LIME WHENCE DERIVED. 611 
 
 in the bed of the ocean, or from rivers fed by calcareous 
 springs, or impregnated with lime derived from disintegrated 
 rocks, both volcanic and hypogene. If this be admitted, the 
 greater proportion of limestone in the more modern forma- 
 tions as compared to the most ancient, will be explained, for 
 springs in general hold no argillaceous, and but a small 
 quantity of siliceous matter in solution, but they are con- 
 tinually subtracting calcareous matter from the inferior 
 rocks. The constant transfer, therefore, of carbonate of lime 
 from the lower or older portions of the earth's crust to the 
 surface, must cause at all periods, and throughout an inde- 
 finite succession of geological epochs, a preponderance of 
 calcareous matter in the newer as contrasted with the older 
 formations. 
 
 CONCLUDING KEMAKKS. 
 
 In the concluding chapters of the First Book, I examined in 
 detail a great variety of arguments which have been adduced 
 to prove the distinctness of the state of the earth's crust at 
 remote and recent epochs. Among other supposed proofs of 
 this distinctness, the dearth of calcareous matter, in the 
 ancient rocks above adverted to, might have been considered. 
 But it would have been endless to attempt to reply to all 
 the objections urged against those who would represent the 
 course of nature at the earliest periods as resembling in all 
 essential circumstances the state of things now established. 
 We have seen that a strong desire has been manifested to 
 discover in the ancient rocks the signs of an epoch when 
 the planet was uninhabited, and when its surface was in a 
 chaotic condition and uninhabitable. The opposite opinion, 
 indeed, that the oldest of the rocks now visible may be the 
 last monuments of an antecedent era in which living beings 
 may already have peopled the land and water, has been de- 
 clared to be equivalent to the assumption that there never 
 was a beginning to the present order of things. 
 
 BR 2 
 
612 CONCLUDING EEMAKKS. 
 
 With equal justice might an astronomer be accused of 
 asserting that the works of creation extended throughout 
 infinite space, because he refuses to take for granted that the 
 remotest stars now seen in the heavens are on the utmost 
 verge of the material universe. Every improvement of the 
 telescope has brought thousands of new worlds into view ; 
 and it would, therefore, be rash and unphilosophical to 
 imagine that we already survey the whole extent of the vast 
 scheme, or that it will ever be brought within the sphere of 
 human observation. 
 
 But no argument can be drawn from such premises in 
 favour of the infinity of the space that has been filled with 
 worlds ; and if the material universe has any limits, it then 
 follows, that it must occupy a minute and infinitesimal point 
 in infinite space. 
 
 So if, in tracing back the earth's history, we arrive at the 
 monuments of events which may have happened millions of 
 ages before our times, and if we still find no decided evidence 
 of a commencement, yet the arguments from analogy in 
 support of the probability of a beginning remain unshaken ; 
 and if the past duration of the earth be finite, then the 
 aggregate of geological epochs, however numerous, must 
 constitute a mere moment of the past, a mere infinitesimal 
 portion of eternity. 
 
 It has been argued, that, as the different states of the 
 earth's surface, and the different species by which it has been 
 inhabited have all had their origin, and many of them their 
 termination, so the entire series may have commenced at a 
 certain period. It has also been urged, that, as we admit 
 the creation of man to have occurred at a comparatively 
 modern epoch as we concede the astonishing fact of the 
 first introduction of a moral and intellectual being so also 
 we may conceive the first creation of the planet itself. 
 
 I am far from denying the weight of this reasoning from 
 analogy ; but although it may strengthen our conviction, 
 that the present system of change has not gone on from 
 eternity, it cannot warrant us in presuming that we shall be 
 permitted to behold the signs of the earth's origin, or the 
 evidences of the first introduction into it of organic beings. 
 
CONCLUDING KEMAKKS. 013 
 
 We aspire in vain to assign limits to the works of creation 
 in space, whether we examine the starry heavens, or that 
 world of minute animalcules which is revealed to us by the 
 microscope. We are prepared, therefore, to find that in 
 time also the confines of the universe lie beyond the reach of 
 mortal ken. But in whatever direction we pursue our re- 
 searches, whether in time or space, we discover everywhere 
 the clear proofs of a Creative Intelligence, and of His fore- 
 sight, wisdom, and power. 
 
 As geologists, we learn that it is not only the present 
 condition of the globe which has been suited to the accom- 
 modation of myriads of living creatures, but that many former 
 states also have been adapted to the organisation and habits 
 of prior races of beings. The disposition of the seas, con- 
 tinents, and islands, and the climates, have varied; the 
 species likewise have been changed ; and yet they have all 
 been so modelled, on types analogous to those of existing 
 plants and animals, as to indicate, throughout, a perfect 
 harmony of design and unity of purpose. To assume that 
 the evidence of the beginning or end of so vast a scheme lies 
 within the reach of our philosophical enquiries, or even of our 
 speculations, appears to be inconsistent with a just estimate 
 of the relations which subsist between the finite powers of 
 man and the attributes of an Infinite and Eternal Being. 
 
GENERAL INDEX. 
 
 ABB 
 
 ABBOT, Gen., on Mississippi, i. 442, 
 445, 452, 458 
 Abich on Vesuvian eruptions, i. 629 ; 
 
 ii. 224 
 
 Adams, Mr., on fossil elephant, i. 184 
 Adams and Murie, Messrs., on shells of 
 
 Nile delta, i. 438 
 Adhemar on recession of glaciers before 
 
 1248, i. 278 
 
 attraction of ocean by ice, i. 272 
 
 Adige, delta of, i. 423 
 
 Adria, formerly a seaport, 425 
 
 Adriatic, depth of, and deposits in, i. 
 
 426 ; ii. 577 
 
 fossils of, i. 54, 57 
 
 jEgean sea, Professor Forbes' dredging 
 
 in, ii. 372 
 
 Africa, S., extreme heat of soil in, i. 277 
 African sands, drifting of, ii. 507 
 Agassiz on delta of the Amazons, i. 467 
 
 G-len Koy roads, i. 377 
 Lake Superior, i. 421 
 
 motion of glaciers, i. 369, 370 
 
 coral reefs, ii. 588 
 
 coincidence of human races and 
 
 zoological provinces, ii. 473 
 
 glacier of Amazons, i. 468 
 multiple origin of the human race, 
 
 ii. 475 
 Air-breathers, scarcity of, in primary 
 
 rocks, i. 155 
 
 Airthrey, fossil whale found at, ii. 573 
 Airy, Professor, cited, i. 291 
 
 on shifting of earth's axis, ii. 208 
 
 Alaska, volcanos in, i. 587 
 Aldborough, incursions of the sea at, i. 
 
 521 
 
 Alderney, Eace of, i. 500 
 Alessandro degli Alessandri, his theory, 
 
 i. 48 
 Aletsch glacier damming up a lake, i. 
 
 378 
 
 Aleutian Isles, volcanos of, i. 585 
 Allan, Dr., on coral in Madagascar, ii. 
 
 584 
 Alluvial plain of Mississippi, i. 457 
 
 deposits, fossils in, ii. 511 
 Alluvium, volcanic, i. 642 
 
 Alps, height of fossil shells in, i. 144 
 
 ANI 
 
 Alps, how much raised during Tertiary 
 epoch, i. 253 
 
 two glacial periods of, i. 196 
 Alternate generation, ii. 327 
 Amazons, delta of, i. 466 
 
 landslips on the, i. 469 
 
 animals floated down on driftwood 
 by, ii. 361 
 
 America, North, floods of, i. 351 
 inroads of the sea in, i. 559 
 
 South, slow rise of land in, i. 131 
 
 probable date of first peopling of, ii. 
 474 
 
 rapid spread of domestic animals 
 over, ii. 457 
 
 Amoorland, quadrupeds common to Eu- 
 rope and, ii. 341 
 
 Ampere on electro-magnetism, ii. 230 
 Amphitherium in Oolite of Stonesfield, 
 
 i. 159 
 Anaximander on origin of men from 
 
 fish, i. 15 
 
 Ancon sheep, origin of the, ii. 312 
 Andes, changes of level in, i. 132 
 
 height of fossil shells in, i. 144 
 
 slow volcanic action of, i. 130 
 
 volcanos of the, i. 579 
 
 Animals, aptitude to domestication .of, 
 ii. 301 
 
 buried in peat, ii. 502, 505 
 
 dispersion of by man, ii. 366 
 
 distribution of plants by, ii. 393 
 
 drifted on floating islands, ii. 362 
 
 drifting on ice-floes of, ii. 360 
 
 effects of some, in exterminating 
 others, ii. 447 
 
 extinct, found with Palaeolithic im- 
 plements, ii. 563 
 
 extirpated by man in Great Britain, 
 ii. 454 
 
 freshwater buried in subaqueous 
 strata, ii. 565 
 
 hybridisation of, ii. 305 
 
 imbedding of in new strata, ii. 536- 
 539 
 
 rapid spread of domestic, over Ame- 
 rica, ii. 457 
 
 six principal provinces of, ii. 335 
 
 tameness of unpersecuted, ii. 303 
 
616 
 
 GENERAL INDEX. 
 
 ANI 
 
 Animals, tamed, often will not breed, ii. 
 313 
 
 their geographical distribution,]!. 329 
 Anio, flood of the river, i. 35-5 
 
 travertin formed by, i. 406 
 Antarctic Continent, its present known 
 
 configuration, i. 259 
 
 regions, cold of, i. 242 
 Aphelion, its effect on climate, i. 275 
 Aphides, multiplication of, ii. 439 
 
 shower of, ii. 379 
 
 Apsides, revolution of, combined with 
 
 precession, i. 274 
 Aqueous and igneous causes contrasted, 
 
 i. 328 ; ii. 97, 237, 243 
 
 causes of change considered, i. 327 
 supposed former intensity of, i. 
 
 106 
 
 lavas, description of, i. 619 
 Arabian writers on geology, i. 27 
 Aradas, Dr., on fossil shells of Etna, ii. 6 
 Arago on formation of ground ice, i. 367 
 
 level of Mediterranean, i. 496 
 
 Archseopteryx or fossil bird in Oolite, 
 
 i. 157 
 
 Archiac cited, i. 426 
 Arctic latitudes, Miocene fossil trees in, 
 
 i. 203 
 
 night, counteracting heat in perihe- 
 lion, i. 281 
 
 Arduino, memoirs of, i. 60, 71 
 
 Argyll, Duke of, his criticisms on theory 
 
 of natural selection, ii. 489 
 Aristotle on deluge of Deucalion, i. 593 
 _ spontaneous generation, i. 34 
 
 opinions of, i. 20 
 Arkansas, floods of, i. 455 
 
 Artesian borings in delta of Ganges, i. 
 478 
 
 well at G-renelle, i. 390 
 Venice, i. 426 
 
 bored at New Orleans, i. 458 
 
 wells explained, i. 388, 391 
 near London, i. 389 
 
 organic remains found in, i. 393 
 
 increase of internal heat shown 
 by, ii. 205 
 
 Arve, section of sand-bank in channel 
 of, i. 490 
 
 Ascension Island, fossil turtle eggs from, 
 ii. 573 
 
 Asia Minor, deposits of coast of, 430 
 
 Astrcsa dipsacea, ii. 582 
 
 Astronomical causes counteracting each 
 other's influence, i. 283 
 
 Astronomy, earlier difficulties of, com- 
 pared to Geology, i. 102 
 
 Astruc on delta of Ehone, i. 428 
 
 Atchafalaya River, the raft of, i. 445 
 
 Atlantic and Pacific oceans, mean level 
 of, i. 496 
 
 BAG 
 
 Atlantic, formation of chalk in, i. 307 
 
 mean depth of, i. 265 
 
 absence of coral reefs in, ii. 608 
 
 islands, age and origin of, ii. 403 
 
 - landshells of, compared witli 
 
 British, ii. 426 
 map showing depth of ocean sxir- 
 
 rounding them, ii. 407 
 probably formed in mid-ocean, ii. 
 
 409 
 
 submarine volcanos of, ii. 63 
 Atlantis, submersion of, i. 13 
 
 Atolls and active volcanos, map of, i. 
 586 
 
 circular coral islands, described, ii. 
 589, 594, 601 
 
 Atrio del Cavallo on Vesuvius, chasm 
 
 cut near, i. 356 
 Attraction of ice, possible effects of, i. 
 
 290 
 
 Austen. See Godwin-Austen. 
 Australia, animals of, i. 159, 163 
 
 coral reefs of, ii. 592 
 Australian Marsupials, ii. 332 
 
 and Indian regions, theory to account 
 for zoological boundary line between 
 the, ii. 352 
 
 region of mammalia, ii. 347 
 Auvergne, calcareous springs of, i. 399 
 
 carbonated springs of, i. 411 
 
 Desmarest on volcanos of, i. 72 
 
 red sandstone of, distinct in age from 
 English, i. 114 
 
 Ava, fossils of, i. 43 
 
 Avantipura, buried temple of in Cash- 
 mere, ii. 354 
 
 Avernus, Lake, i. 602 
 
 Avicenna on cause of mountains, i. 27 
 
 Axis of the earth's orbit, variation in 
 the minor, i. 269 
 
 changes in obliquity of earth's, i. 282 
 
 double, of Etna, ii. 9 
 
 of earth's crust, supposed change in, 
 ii. 208, 241 
 
 Axmouth, landslip, drawing of, i. 537 
 Azores, icebergs drifted to, i. 246 
 
 siliceous springs of, i. 408 
 
 volcanic region of the, i. 591 
 
 birds carried from Europe to, ii. 365 
 of, common to the continent, ii. 
 
 413 
 
 BABBAGE, Mr., on Temple of Serapis, 
 ii. 165, 167, 172 
 
 expansion of rocks by heat, ii. 
 
 235 
 
 Bache, Professor, on width of Gulf- 
 stream, i. 244 
 
 Bachmann Dr., cited, i. 209, 210 
 Bacon, Lord, cited, ii. 557 
 
GENEKAL INDEX. 
 
 617 
 
 BAF 
 
 BIS 
 
 Baffin's Bay, icebergs in, i. 246 
 Bagnes, flood in the valley of, i. 352 
 Bagneres de Luehon, hot springs of, i. 
 
 395 
 Baise, Bay of, elevation and subsidence 
 
 in, ii. 164 
 
 view of Bay of, Plate VII., ii. 176 
 Baker, Colonel, on artificial canals in 
 
 India, i. 477 
 
 Bakewell on Niagara Falls, i. 361 
 Bakie Loch, Charse fossil in, ii. 567 
 Baku, mud volcanos of, ii. 76 
 Baldassari on Siennese fossils, i. 57 
 Bali and Lombok, striking contrast of 
 
 species in, ii. 349 
 Balize, salt springs in the island of the, 
 
 in delta of Mississippi, i. 450 
 Baltic, ice-drifted rocks of, i. 385 ; ii. 
 
 ]82 
 
 waste of coast on, i. 556 
 
 change of its level relatively to the 
 land, ii. 180 
 
 Banks of Mississippi above plain, i. 
 
 443 
 Baobab-tree, its size and probable age, 
 
 ii. 44 
 Barham, Dr., on Ictis being same as 
 
 St. Michael's Mount, i. 542 
 Barrancos of Somma, i. 634 
 Barren Island, geological structure of, 
 
 ii. 74 
 
 view of, ii. 75 
 
 Barrier reefs described, ii. 601 
 Bartlett, Mr., on partridge fasting five 
 
 days, ii. 414 
 
 Basalts, early opinions on, i. 71 
 Bat, peculiar, in Palma, ii. 411 
 Batavia, effects of earthquake at, ii. 
 
 159 
 
 Bates, Mr. H. W., on delta of the Ama- 
 zons, i. 466 
 landslips of the Amazons, i. 
 
 469 
 
 floating pumice, ii. 376 
 modern migration of Eed 
 
 Indian to the tropics, ii. 473 
 explorer of Amazons, ii. 276 
 on two species of butterfly linked 
 
 by varieties, ii. 338 
 
 barriers to migration of ani- 
 mals, ii. 355 
 
 Bath, thermal waters of, i. 398 
 Baths, hot, of San Filippo, i. 402 
 Batrachians, want of, in islands, ii. 412 
 Bayfield, Admiral, on ice-borne boulders, 
 
 i. 366, 384 
 
 depth of Lake Superior, i. 421 
 Beaches, raised sea, i. 290 
 Beachy Head, landslip at, i. 529 
 Bear, supposed entrance into Iceland of 
 
 first polar, ii. 448 
 
 Bears, migrations of, ii. 357 
 
 Beaumont, M. E. de, on change of lev<l 
 in Holland, i. 551 
 
 hypothesis of elevation cra- 
 ters, i. 633 
 
 on moving sand-dunes of 
 Holland, i. 514 
 
 mud filling lagunes, i. 
 
 424 
 
 rents in volcanos, i. 614 
 
 origin of mountain- 
 chains, i. 121, 123 
 
 direction of mountain- 
 ranges, i. 130 
 
 on injection of dykes, ii. 
 
 45 
 
 Beaver, fossil in Perthshire, ii. 536 
 
 Beche, Sir H. See De la Beche. 
 
 Bee, migrations of the, ii. 378 
 
 Beechy, Capt., on coral islands, ii. 585, 
 588, 596, 598 
 
 on drifting of canoes, ii. 468 
 
 on upheaval in Conception Bay, 
 
 ii. 155 
 
 Beila in India, mud volcanos of, ii. 76 
 
 Belcher, Sir Edward, on polar ichthyo- 
 saurus, i. 219 
 
 on upheaval in Conception 
 Bay, ii. 155 
 
 Bell-rock, stones thrown up in storms 
 on, i. 509 
 
 Belzoni, on human beings drowned in 
 Nile flood, ii. 541 
 
 Bengal, Bay of, depth and deposits of, i. 
 483, 485 
 
 Berkeley, Bishop, on modern origin of 
 man, ii. 555 
 
 Bermudas, birds of, common to America, 
 ii. 414 
 
 coral reefs of, ii. 580, 608 
 Bewick, on extinction of bustard in 
 
 England, ii. 456 
 
 Bies Bosch in Holland formed, i. 552 
 Birds, fossil, as bearing on theory of 
 
 progression, i. 157 
 
 carried by wind across Atlantic, ii. 365 
 
 conveying seeds to islands, ii. 419, 421 
 
 driven by gales across the ocean, ii. 
 413 
 
 imbedding of, a rare event, ii. 534 
 
 in Atlantic islands of same species 
 as on mainland, ii. 413 
 
 migration of, ii. 364 
 
 rate of increase and destruction of, 
 ii. 280 
 
 Bischoff, Professor, on carbonic acid in 
 craters, i. 412 
 
 on contraction of granite in so- 
 lidifying, ii. 236 
 
 Biscoe, Captain, on cold of antarctic 
 regions, i. 242 
 
618 
 
 GENERAL INDEX. 
 
 BIS 
 
 BUR 
 
 Bisons, migrations of, ii. 356 
 Bitumen in Niagara limestone, i. 415 
 Bituminous springs, i. 414 
 Blackmore. Dr., on fossil marmot in 
 
 drift, in posture of hibernation, ii. 563 
 Bluffs ' of the Mississippi, i. 462 
 Boa constrictor, migrations of, ii. 366 
 Boblaye on engulfed rivers and caves 
 
 in Morea, ii. 516, 518 
 
 M., on ceramique in Morea, ii. 513 
 Bog iron-ore, whence derived, ii. 501 
 Bogota, earthquake of 1827 in, ii. 94 
 Bolgen, blocks in flysch of, i. 210 
 Bone breccias in open fissures and caves, 
 
 ii. 521 
 ' Bone-bed ' composed of fish-bones now 
 
 forming in deep sea, ii. 576 
 Bonelli, Professor, cited, i. 199 
 
 on swarms of migratory butterflies, 
 ii. 378 
 
 ' Bore,' tidal wave called the, i. 560 
 Borings, Artesian. See Artesian Wells. 
 Borneo and Celebes, partial fusion of 
 
 mammalia in, ii. 351 
 Bosphorus, deluges on shores of, i. 593 
 Botanical geography, ii. 381 . See Plants. 
 Botzen, stone-capped pillars of, i. 335 
 Boucher de Perthes, M., on Gallo-Ro- 
 
 man remains in peat, ii. 499 
 Boue, M., cited, i. 391 
 Boulders drifted by ice, i. 385 
 
 stranded by ice, i. 384 
 Bournemouth, submarine forest at, ii. 
 
 529 
 
 flint tools in drift at, ii. 5 
 Boussingault, M., on volcanos in Andes, 
 
 i. 582 
 Bowen, Lieutenant, on boulders in ice, 
 
 i. 365 
 
 Boyle on agitation of sea, i. 39 
 Brace on variation of the Anglo-Ameri- 
 can, ii. 471 
 
 Bracini on Vesuvian eruptions, i. 618 
 Brahmapootra, sediment brought down 
 by, i. 483 
 
 delta of the, i. 470-483 
 Brahminical doctrines, i. 7-12 
 Brain, comparison of Negro and Euro- 
 pean, ii. 487 
 
 classification of mammalia with refer- 
 ence to the, ii. 486 
 
 Brander on Hampshire fossils, i. 64 
 Bravais, M., on upraised sea-coast in 
 
 Norway, ii. 195 
 
 Brazil caves, extinct animals in, ii. 333 
 Breccias in caves now forming in the 
 
 Morea, ii. 516 
 
 Breeding in and in injurious, ii. 321 
 Bridlington, marine arctic shells of, i. 
 
 197 
 
 beds, possible date of, i. 297 
 
 Brieslak on Vesuvius, i. 619 
 
 Briggs, Mr., on water-borings in Egypt, 
 
 i. 391 
 
 Brighton, waste of cliffs of, i. 530 
 Brine springs, i. 410 
 Brine, Commander, on Santorin volcanic 
 
 eruption, ii. 170 
 Bringier, Mr., on earthquake of New 
 
 Madrid, ii. 108 
 
 Bristol Channel, currents in, i. 500 
 British and Atlantic islands, landshells 
 
 of, compared, ii. 426 
 Brittany, waste of coast of, i. 547 
 Broca on long persistency of negro and 
 
 other types, ii. 471 
 Brocchi cited, i. 425, 426 
 
 on fossil conchology, i. 31 
 dying-out of a species, ii. 268 
 
 Broderip, Mr., on opossum of Stones- 
 field, i. 160 
 
 extinction of the Dodo, ii. 457 
 
 long vitality of mollusca, ii. 
 
 374 
 
 crab covered with oysters, ii. 
 
 376 
 Brongniart, Adolphe, cited, i. 218 
 
 on climate of Carboniferous period, 
 
 i. 226 
 
 M. Alex., on raised marine strata in 
 Sweden, ii. 192 
 
 Bronze and stone ages, climate of, i. 
 
 176 
 Brown, Dr. R., on plants of Africa, 
 
 Guiana, and Brazil, ii. 391 
 on origin of gulf-weed, ii. 392 
 
 Mr. James, on flint implements in 
 Hampshire drift, ii. 561 
 
 Buch. See Von Buch. 
 
 Buckland, Dr., on Indian fossils, i. 10 
 
 landslip near Axmouth, i. 538 
 
 fossils in caves, ii. 520 
 
 Buffon, his theory of the earth, i. 57 
 
 On extinction of species, ii. 461 
 
 geographical distribution of ani- 
 mals, ii. 329 
 
 ' natural barriers,' ii. 331 
 
 Bunbury, Sir C., on Brazilian plants, ii. 
 
 385 
 Miocene flora of Madeira, ii. 
 
 406 
 Bunsen, Prof. R., on mineral springs of 
 
 Iceland, i. 408 
 
 - Icelandic geysers, ii. 215, 
 
 219,221 
 
 hydrogen in volcanic erup- 
 tions, ii. 224 
 
 mud volcanos, ii. 75 
 
 Burchell, Mr., on dispersion of plants, 
 
 ii. 399 
 Burckhardt on caravans buried in blown 
 
 sand, ii. 508 
 
GENERAL INDEX. 
 
 619 
 
 BUR 
 
 CHE 
 
 Burnes, Sir A., on different colour of 
 water in Indian rivers, i. 310 
 
 earthquake of Cutch, ii. 99, 
 
 101 
 
 Burnet, his theory of the earth, i. 47 
 Burrampooter. See Brahmapootra. 
 Butler, his satire on Burnet, i. 47 
 Butterflies, migration of, ii. 378 
 transitional forms of, in valley of 
 Amazons, ii. 338 
 
 CABBAGE, modifications effected in 
 
 U the, ii. 299 
 
 Calabria, earthquake of 1783, ii. 113 
 
 geological structure of, ii. 117 
 Calabrian earthquake, destruction of life 
 
 in, ii. 140 
 
 landslips caused by, ii. 130, 133 
 lakes formed by, ii. 127 
 
 towns, ancient, on hill-tops, ii. 143 
 Calanna, modern lavas in valley of, ii. 
 
 31, 34 
 Calcareous springs, i. 399 
 
 precipitates, i. 404 
 Calcutta, Artesian well at, i. 478 
 Caldcleugh, Mr., on earthquakes in 
 
 Chili, ii. 90 
 
 Caldera, or Atrio of Vesuvius, i. 634 
 Callao, town destroyed by sea, ii. 158 
 
 changes caused by earthquakes at, 
 ii. 156 
 
 Campagna di Roma, calcareous deposits 
 
 of, i. 404 
 Campania, populous in spite of V9lcanic 
 
 eruptions, i. 654 
 
 Canaries, landshells of the, ii. 426 
 Cannon in calcareous rock, ii. 549 
 Canoes buried in Scotland, ii. 548 
 
 drifting of, to vast distances, ii. 467 
 Capri, palace of Tiberius under water 
 
 at, ii. 176 
 
 Carbonic acid, disengagement of free, 
 i. 412 
 
 supposed excess in Coal period, 
 
 i. 227 
 Carboniferous epoch, plants of, 224 
 
 warmth of, referred by Mr. Croll 
 
 to astronomical causes, i. 272 
 
 how far universal, i. 116 
 
 warm climate of, i. 224 
 
 shells and corals of, i. 228 
 
 Cardano on petrified shells, i. 34 
 Cardium pygmaum, swimming appa- 
 ratus of, ii. 375 
 Carpenter on regrowth of amputated 
 
 extra fingers, ii. 478 
 Carraccas, earthquakes in, ii. 106, 112 
 Carrara marble, i. 143 
 Caryophyllia fastigiata, ii. 582 
 Cashmere, buried temples of, ii. 553 
 
 Caspian Sea, level of, i. 1 1 1 
 Cataclysmal theory of Stoics, i. 13 
 Catania, in part overwhelmed by lava, 
 . ii. 22 
 
 Catarrhine or old-world monkeys, ii. 331 
 Catastrophes, theories respecting, i. 8, 
 
 9, 32 
 
 Catcott, his treatise on the Deluge, i. 62 
 Caterpillars, devastations caused by, ii. 
 
 439 
 Catt, Mr., on erratic block in chalk, i. 
 
 218 
 Cattle, decrease in size of half- wild, ii. 
 
 321 
 Causes, supposed intensity of ancient, i. 
 
 102 
 
 supposed discordance of ancient and 
 modern, i. 102 
 
 Cautley, Sir P., on artificial canals in 
 
 India, i. 477 
 fossils of Siwalik Hills, i. 
 
 201 
 bones of deer in well at 
 
 Behat, ii. 521 
 
 buried Hindoo town, ii. 
 
 512 
 Cava Grande, Etna, inclined lava of, ii. 
 
 35, 36 
 Caves, fossils buried in, ii. 514, 520, 
 
 522 
 Cebus, transitional forms of two species 
 
 of, ii. 339 
 Celsius on sinking of Baltic, i. 49 ; ii. 
 
 339 
 Central fluidity, not required to account 
 
 for volcanic phenomena, ii. 211, 241 
 of the earth discussed, ii. 199, 
 
 209 
 
 Central France, lavas eroded in, i. 356 
 Centres, specific, of creation, ii. 336 
 Cephalonia, earthquakes in, ii. 116 
 Cerebral, development in vertebrata, 
 
 including man, ii. 485 
 Cesalpino on organic remains, i. 34 
 Cetacea, absence of, in secondary rocks. 
 
 i. 162 
 
 imbedding of, ii. 572 
 
 Chalk, floating ice in sea of, i. 216 
 
 warm climate indicated by fossils of, 
 i. 213 
 
 Chamisso, M., on coral islands, ii. 587 
 
 Chamouni, glaciers of, i. 369 
 
 Chara kispida, stem and seed-vessels of, 
 
 ii. 566, 567 
 
 Charse fossilised in Scotch marl, ii. 566 
 Charpentier on motion of glaciers, i. 369 
 
 glacier moraines, i. 375 
 
 Chasms left by Calabrian earthquake, ii. 
 
 126 
 Chemical action in volcanic eruptions, 
 
 ii. 232, 242 
 
620 
 
 GENERAL INDEX. 
 
 CHE 
 
 COS 
 
 Chepstow, rise of tides at, i. 494 
 Cheshire, waste of coast of, i. 546 
 Chesil Bank, formation of, i. 534 
 Chili, rainless coast regions of, i. 332 
 
 volcanos of, i. 579 
 
 upheaval of coast in, i. 580 ; ii. 96 
 
 upheaval of rock, 1822-35, i. 133 
 
 earthquakes in, ii. 89, 94, 154, 190 
 
 map of, ii. 91 
 
 Chilian Andes, lakes of lava in, i. 118 
 
 Chillesford, marine arctic shells of, i. 197 
 
 Chillingham cattle, ii. 321 
 
 Chimborazo, height of, i. 249 
 
 China, climate of, i. 239 
 
 Chinese deluge, i. 10 
 
 Christy, Mr., on implements of the 
 
 Keindeer period, ii. 559 
 Cimbrian deluge, i. 558 
 Cisterna on Etna now formed, ii. 1 9 
 Cities, engulfed, ii. 553-555 
 Clarke, Dr., on lava in motion, i. 623 
 
 Kev. ~W. B., on Bournemouth sub- 
 marine peat, ii. 531 
 
 Cleavage, or slaty structure, i. 142 
 Climate, as affected by former geogra- 
 phical change, i. 260 
 
 astronomical causes of change of, i. 
 268 
 
 causes of change of, i. 233 
 
 concluding remarks on, i. 231 
 
 former vicissitudes of, i. 174 
 
 how affected by obliquity of ecliptic, 
 i. 283 
 
 of Carboniferous period, i. 224 
 Bronze and Stone age, i. 176 
 
 Devonian period, i. 229 
 European drift and cave deposits, 
 
 i. 192 
 
 Eocene strata, i. 204 
 
 Lower Miocene strata, i. 202 
 
 Oolitic and Triassic periods, i. 218 
 
 Permian period, i. 222 
 
 Silurian period, i. 231 
 
 successive phases of precession, i. 
 
 280 
 
 Glacial epoch, i. 194 
 
 Interglacial, i. 195 
 
 Pliocene period, i. 198 
 
 Miocene period, i. 199 
 
 the Chalk period, i. 213 
 
 three causes affecting, i. 275 
 
 slow change of, owing to great depth 
 of ocean, i. 265 
 
 effect of, on Himalayan plants, ii. 319 
 Climates, map of distribution of land 
 
 which might produce extreme, i. 266 
 
 extreme, caused by excentricity, i. 
 270 
 
 Coal, reptiles of, i. 229. See Car- 
 boniferous. 
 Coast-ice, i. 383 
 
 Codrington, Mr. T., on flint implement 
 
 in gravel, Isle of Wight, ii. 562 
 Coins, &c., sunk in the bed of the sea, 
 
 ii. 551 
 Cold of southern hemisphere, causes of, 
 
 i. 277 
 
 Colebrooke, Mr. H. T., on crocodiles of 
 Ganges, i. 473 
 
 sediment of Ganges, i. 
 472 
 
 age of Vedas, i. 6 
 
 Collini on igneous rocks of Ehine, i. 71 
 Colonna, Fabio, on fossil shells, i. 35 
 Conception Bay, elevation of, ii. 155 
 animals drowned during earth- 
 quake at, ii. 540 
 Cone of Vesuvius, structure of, i. 620 
 
 Etna, truncated, ii. 19 
 
 Cones, lateral, of Etna, ii. 2 
 
 growth of volcanic, like exogenous 
 trees, ii. 44 
 
 Conglomerates, formation of, i. 491 
 Continental extension not applicable to 
 
 Atlantic islands, ii. 406, 428 
 Continents, antiquity of existing, i. 253 
 Conybeare, Eev. W. D., on Lister, i. 40 
 landslip near Axmouth, 
 
 i. 538 
 Coode, Mr., on shingle moved by a 
 
 storm, i. 535 
 Cook, Captain, on climate of South 
 
 Georgia, i. 240 
 
 the cause of antarctic cold, i. 
 
 242 
 
 drifting of canoes, ii. 467 
 
 Coral islands, absence of, in Atlantic, 
 
 ii. 608 
 downward movement, slow and 
 
 uniform, ii. 601 
 origin of the circular form of, ii. 
 
 589, 590 
 
 rate and mode of growth of, ii. 581, 
 586, 604 
 
 reefs, formation of, ii. 579 
 Corals of Carboniferous period, i. 228 
 
 West Indian, proving former sub- 
 mergence of isthmus of Panama, i. 
 254 
 
 Cordier, M. on temperature of earth's 
 
 interior, ii. 205 
 Cornwall, waste of coast in, i. 543, 545 
 
 drift sand in, ii. 508 
 
 Corolla, coloured, in flowers fertilised by 
 
 insects, ii. 309 
 Coromandel, inundations of sea on coast, 
 
 ii. 512 
 Corona Boroalis, increased brightness 
 
 of a star in, i. 303 
 Correlation of growth, ii, 314 
 Coseguina volcano, great eruption of, i. 
 
 583 
 
GENERAL INDEX. 
 
 021 
 
 COS 
 
 DAR 
 
 Cosmogony of Egyptians, i. 12, 13 
 
 Hindoos, i. 6 
 the Koran, i. 28 
 
 not geology, i. 4 
 Cosmopolite species of shells, ii. 374 
 Cotopaxi volcano, explosive power of, ii. 
 
 223 
 
 Cowper, the poet, on age of earth, i. 81 
 Crag, climate of the, i. 199 
 Craters of elevation. See Elevation 
 
 Craters. 
 Crawfurd, Mr., on fossils in Ava, i. 43 
 
 on drifting of canoes, ii. 468 
 
 on earthquake of Sumbawa, ii. 105 
 Creation, specific centres of, ii. 336 
 Cretaceous reptiles, i. 214 
 Crocodiles of the Ganges, i. 473 
 Croll, Mr. J., on causes of change of cli- 
 mate in geological periods, i. 271, 272 
 
 computation of earth's former 
 
 excentricity by, i. 292 
 
 on effect of polar ice-cap, i. 291 
 
 on submergence of land by at- 
 traction of ice, i. 272, 289 
 Cromer, forest bed of, i. 197 
 Cross-breeds, reversion to parent stock 
 
 of, ii. 290 
 
 Crosses, slight, beneficial, ii. 320-322 
 Crotch, Mr., on beetles of Azores, ii.417 
 Cruikshank, Mr., on retreat of sea in 
 
 Chilian earthquake, ii. 95 
 Crystalline rocks, whether formerly more 
 largely formed, i. 143 
 
 contemporary with fossiliferous, 
 ii. 210, 241 
 
 Cuba, stalagmitic limestone of, ii. 522 
 Gumming, Rev. J. C., on Devonian 
 
 boulder clay, i. 230 
 Cunningham, Major, on buried temples 
 
 of Cashmere, ii. 555 
 Currents affecting polar temperature, i. 
 
 237 
 
 and rivers, comparative transporting 
 powers of, i. 570 
 
 causes of, i. 495 
 
 destroying and transporting power 
 of, i. 502 
 
 deposits, how arranged by, i. 572 
 
 effects of, in equalising temperature, 
 i. 243 
 
 in Straits of Gibraltar, i. 562 
 
 greatest velocity of. i. 499 
 
 how affected by rotation of the earth, 
 i. 500 
 
 stream and drift, 496 
 
 tidal, excavatinganddepositingpower 
 of, i. 565-568 
 
 agency of, in dispersion of plants, ii. 
 389 
 
 Curtis, Mr., on fossil insects, ii. 533 
 
 on ravages of insecrs. ii. 439 
 
 Curves of the Mississippi, i. 442 
 Cutch, submergence by earthquake, 
 1819, i. 11 
 
 earthquake of, ii. 97, 553 
 
 ruins of, described, ii. 102 
 Cuvier, his Geological Works, i. 87 
 
 on fossil mammalia, i. 158 
 
 doctrines of Anaximander, i. 16 
 
 identity of Egyptian mummies 
 
 with living species, ii. 264 
 variation in canine races, ii. 262 
 
 F., on domestication of animals, ii. 301 
 Cycles of precession, how divided, i. 274 
 Cypris, fossil in Scotch travertin, ii. 568 
 Cypris unifasdata and vidtia, ii. 568 
 
 DANA, Mr., on ' cinder ' and ' tufa ' 
 cones, i. 615 
 
 volcanos of Sandwich Isles, i. 
 
 591 
 Daniell, Mr., on expansion of platinum, 
 
 ii. 207 
 
 Dante quoted, i. 76, 424 
 Darby on lakes formed by Red River, i. 
 457 
 
 delta of Mississippi, i. 457 
 Darwin, Mr. C., his map of Volcanos 
 
 and Coral Reefs,' i. 586 ; ii. 603 
 on absence of raised deposits con- 
 taining recent shells in Chili, i. 319 
 
 crateriform hills of Galapagos, 
 
 i. 615 
 
 colour of rivers, i. 310 
 
 evaporation of snow in Chili, 
 
 i. 286 
 formation of peat, i. 228 
 
 glacier reaching the sea in 
 Chili, i. 380 
 
 migration of species between 
 
 Old and New World, i. 264 
 
 rolled shingle of South Ame- 
 rican coast, i. 573 
 
 rise and subsidence of coral 
 
 reefs, i. 250 
 
 luxuriant vegetation not re- 
 quired for large Mammalia, i. 190 
 
 stones carried by floating trees, 
 
 i. 217 
 
 snow line in Tierra del Fuego. 
 i. 241 
 
 slow volcanic action of Andes, 
 i. 130 
 
 absence of mammalia and ba- 
 trachians in islands, ii. 412 
 
 Atlantic submarine volcanos, 
 ii. 64 
 
 - barriers to migration of ani- 
 mals, ii. 355 
 
 vibratory motion of earth- 
 quake, ii. 120 
 
622 
 
 GENERAL INDEX. 
 
 DAE 
 
 Darwin, Mr. C., on coral islands, ii. 
 584, 586, 589 
 
 cause of their circular form, ii. 
 
 591 
 
 coloured corolla attracting in- 
 sects, ii. 309 
 
 correlated variability, ii. 314 
 decrease of bulk in half- wild 
 
 cattle, ii. 321 
 earthquakes, ii. 89 
 
 elevated marine strata at Lima, 
 ii. 158 
 
 geographical relationship of 
 
 fossil to living mammalia, ii. 334 
 
 growth of coral, ii. 574, 599 
 natural hybrids, ii. 324 
 
 ' incipient species,' ii. 462 
 limits to variability of a 
 
 species, ii. 300 
 
 multiple origin of the dog, ii. 
 293 
 
 natural selection, ii. 277-281, 
 
 316 
 
 against theory of ' necessary de- 
 velopment,' ii. 488 
 
 on our ignorance of laws of va- 
 riation, ii. 490 
 
 pangenesis, ii. 291 
 
 regrowth of supernumerary 
 
 digits in man, ii. 477 
 
 retreat of sea during earth- 
 quakes, ii. 151 
 
 reversion of ' feral ' pigs to 
 
 the wild type, ii. 304 
 
 seeds attached to birds' feet, ii. 
 
 326 
 
 seeds conveyed in locust dung, 
 ii. 420 
 
 seeds uninjured by salt water, 
 
 ii. 391 
 
 sheep herding apart, ii. 311 
 
 tameness of Galapagos birds, 
 
 ii. 303 
 
 unconscious selection, ii. 288 
 
 ' variation,' ii. 285, 289,291, 297 
 
 wading birds of Galapagos, ii. 
 415 
 
 Darwin and Wallace's essays on spe- 
 cies, ii. 278 
 
 Dates in geology, how far determinable 
 by variations of excentricity, i. 295 
 
 Daubeny, Dr., on Vesuvius, i. 630 
 
 volcanos, i. 592 ; ii. 53 
 
 springs, i. 395, 397 
 
 gases in mud volcanos, ii. 76 
 
 hydrogen and nitrogen in vol- 
 canic eruptions, ii. 224, 226 
 Davis, Mr., on Chinese deluge, 10 
 Davy, Dr., on Graham Island, ii. 6 3 
 
 helmet taken from sea nea r 
 
 Corfu, ii. 550 
 
 DEL 
 
 Davy, Rev. C., on vessel engulfed at 
 
 Lisbon, ii. 148 
 Davy, Sir H., on formation of travertin, 
 
 i. 404 
 progressive development, 
 
 i. 146 
 
 lake of the Solfatara, i. 404 
 
 his analysis of peat, ii. 496 
 
 on metallic bases, ii. 232 
 
 salt deposited by volca- 
 nos, ii. 224, 226 
 
 the races of man, ii. 465 
 
 Dawson, Dr., on American Devonian 
 
 flora, i. 149, 230 
 submerged forest of Bay of 
 
 Fundy, ii. 532 
 Dead Sea, level of, i. 112 
 Dease and Simpson on strata com- 
 pressed by ice, i. 382 
 De Beaumont. See Beaumont 
 De Candolle, Alphonse, on provinces of 
 
 plants, ii. 384 
 
 Aug., on botanical regions, ii. 382 
 
 dispersion of plants by 
 
 man, ii. 397, 399 
 
 extinction of species, ii. 435 
 
 on hybrid species, ii. 325 
 
 on longevity of trees, ii. 45 
 
 South American useful plants, 
 
 ii. 287 
 Decken, Baron Von Der, on snow-capped 
 
 mountain on the equator, i. 248 
 De la Beche, Sir H., on delta of Rhone, 
 
 i. 417 
 
 submarine forest, i. 543 
 
 subsidence of Port Royal, 
 
 ii. 161 
 
 Delta of the Amazons, i. 466 
 Ganges and Brahmapootra, i. 
 
 471 
 Mississippi River, antiquity of, 
 
 i. 457, 461 
 
 Nile, i. 431 
 
 Po and Adige, 423 
 
 marine, of the Rhone, i. 427 
 
 of Ganges and Indus, alternate fresh- 
 water and marin^ beds in the, ii. 570 
 
 Deltas, age of existing, i. 485 
 
 convergence of, 484 
 
 formed by tides, i. 440 
 
 grouping of strata in, i. 486 
 
 in lakes, i. 416, 421 
 
 mud, how deposited in, i. 309 
 
 concluding remarks on, i. 484 
 
 De Luc, his treatise on Geology, i. 82, 84 
 on conversion of forests into peat- 
 mosses, ii. 500 
 
 Deluge, fossil shells referred to, i. 31, 35 
 Deluges, supposed causes of, i. 110 
 
 traditions of, i. 593 
 
 in Chili, ii. 154 
 
GENERAL INDEX. 
 
 623 
 
 DEN 
 
 EAR 
 
 Denmark, inroads of the sea in, i. 557 
 Denudation and deposition, i. 107 
 Deposition and denudation, parts of the 
 
 same process, i. 107 
 Deposits, stony, of the Ehone delta, i. 
 
 429 
 
 De Saussure on motion of glaciers, i. 369 
 Descloizeaux on Icelandic geysers, ii. 220 
 Deshayes, on fossil shells of Etna, ii. 5 
 Desmarest, his definition of Geology, i. 4 
 
 on volcanos of Auvergne, i. 72 
 Desor, M., on fish found in Artesian 
 
 wells, i. 393 
 
 glacier motion, i. 371 
 
 tropical aspect of some beds 
 
 associated with flysch, i. 210 
 Deucalion's deluge, i. 593 
 Devi lie, St. Claire, on contraction of 
 
 granite, i. 134 
 
 hydrogen in volcanic eruptions, 
 
 ii. 224 
 
 contraction of granite in so- 
 lidifying, ii. 236 
 Devonian period, supposed ice-action of, 
 
 i. 230 
 
 climate of, i. 229 
 Devonshire, waste of coast in, i. 538 
 Dezertas, land-shells of, common to 
 
 Madeira, ii. 425 
 
 Monizia edulis, a plant peculiar to 
 the, ii. 418 
 
 Diatomaceae in volcanic tuff, i. 644 
 Dikes in Vesuvius, how formed, i. 627 
 
 greenstone of Etna, ii. 9 
 
 in Val del Bove, on Etna, ii. 16 
 
 rarity of, far from eruptive centres, 
 ii. 17 
 
 Diluvial theories, i. 38, 44 
 
 Diodorus Siculus on Samothracian de- 
 luge, i. 593 
 
 on St. Michael's Mount, Cornwall, 
 
 i. 539 
 
 Dion Cassius on Herculaneum and Pom- 
 peii, i. 604 
 
 Disco Island, in Greenland, Miocene 
 fossil trees near, ii. 203 
 
 Dodo, extinction of the, ii. 456 
 
 Dog, different races*, how far varying, 
 ii. 263 
 
 Lamarck on origin of, ii. 250 
 
 multiple origin of the, ii. 293 
 
 inherited instincts in, ii. 294 
 
 introduced in Juan Fernandez, de- 
 stroyed the goats, ii. 450 
 
 Dogger Bank, heaping up of the, i. 569 
 Dollart, how formed, i. 555 
 Dolomieu on basalt of Etna, i. 73 
 
 Calabrian earthquake, ii. 117, 123, 
 129, 140 
 Domestic races breed together, ii. 284 
 
 varieties becoming ' feral,' ii. 304 
 
 Domestication, aptitude of some animals 
 for, ii. 301 
 
 Lamarck on effects of, ii. 250 
 Domesticity eliminating sterility, ii. 312 
 Donati on deposits in Adriatic, i. 426 
 bed of Adriatic, i. 57 
 
 Donny, Mr., on the heating of water 
 
 freed from air, ii. 220 
 D'Orbigny. See Orbigny. 
 Dorsetshire, landslip and waste of cliffs 
 
 in, i. 536 
 Dove, Professor, on mean annual iso- 
 
 thermals, i. 239 
 on heat of surface of the earth 
 
 in aphelion, i. 275 
 Dover, formation of Straits of, i. 516 
 
 waste of cliffs of, 515 
 Downham, town overwhelmed by sand 
 
 flood, ii. 508 
 
 Dranse, River, flood of, i. 354 
 Drift, climate of European, i. 192 
 Drift sand, fossils in, ii. 508 
 Driftwood of Mississippi, i. 646 
 
 Mackenzie River, ii. 526 
 
 Drinkwater on 'Life of Galileo' (note), 
 
 i. 83 
 Druids, their theory of the universe, i . 
 
 25 
 Duchassaing, M., on depth of coral 
 
 growth in the sea, ii. 580 
 Dufrenoy, M., on formation of Monte 
 
 Nuovo, i. 610 
 hypothesis of elevation craters, i. 
 
 633 
 Dujardin, M., on shells and seeds rising 
 
 in Artesian wells, i. 393 
 Duncan, Dr., on West Indian corals, i. 
 
 254 
 
 coral reefs, ii. 606 
 
 growth of corals, ii. 581 
 
 Dunes, hills of blown sand, i. 514 
 Dunwich, destruction of, by the sea, i. 
 
 519 
 Dwarfs Tower, near Viesch, i. 342 
 
 EARTH, antiquity of the, i. 32 
 density of the, ii. 202 
 
 section of the, showing outer crust, 
 ii. 212 
 
 spheroidal figure of, does not prove 
 original fluidity, ii. 199, 240 
 
 supposed central fluidity of, ii. 199 
 
 theories of original formation of the, 
 ii. 200 
 
 Earth-pillars formed by rain, i. 335 
 
 in Switzerland, i. 340 
 
 diagram of formation of, i. 337 
 Earthquake at Visp destroyed earth- 
 pillars, i. 341 
 
 focus, depth of, ii. 139 
 
624 
 
 GENERAL INDEX. 
 
 EAR 
 
 Earthquake of Calabria, 1783, ii. 113 
 
 - Lisbon, 1755, ii. 147 
 New Zealand, ii. 82 
 
 wave, rate of movement of, ii. 149, 
 151 
 
 waves, complicated action of, ii. 139 
 focus of how determined, ii. 136, 
 
 138 
 origin and mode of action of, ii. 
 
 135, 140 
 
 changes caused by, ii. 162 
 
 chronologically described, ii. 82 et 
 seq. 
 
 deficient accounts of ancient, ii. 80 
 
 deficiency of historical records of, ii. 
 164 
 
 elevation of land during, ii. 82, 94 
 
 effects of, in the 19th century, ii. 110 
 
 excavation of valleys aided by, ii. 129 
 
 intimately connected with volcanos, 
 ii. 198 
 
 of 17th century, ii. 158 
 
 19th century, ii. 80-111 
 18th century, ii. 112-158 
 
 phenomena attending, ii. 81 
 
 radiation of, from a deep-seated cen- 
 tre, ii. 119, 129 
 
 and volcanos, recapitulation of causes 
 of, ii. 240 
 
 Earth's axis of rotation, hypothesis of 
 change in, i. 504 
 
 primitive heat, gradual diminution 
 of, i. 303 
 
 cooling from a state of fusion, ii. 
 226 
 
 shifting of axis of, ii. 208, 241 
 
 thickness of the crust of, ii. 203, 206 
 
 flexibility of the crust of, ii. 227 
 Eccles church buried in blown sand, i. 
 
 513 
 
 views of, taken in 1839, 1862, i. 
 
 514 
 
 Ecliptic, variation in obliquity of, affect- 
 ing climate, i. 282 
 
 Edmonstone island, i. 476 
 
 Egerton, Kev. W. H., on Indian fossils, 
 i. 213 
 
 Eggs of mollusca attached to floating 
 wood, ii. 377 
 
 Egypt, towns buried by sand in, ii. 507 
 
 Egyptian cosmogony, 12, 13 
 
 mummies identical with living 
 species, ii. 263 
 
 Ehrenberg on infusoria in tuff, i. 645 
 
 ashes enveloping Pompeii, i. 644 
 
 origin of bog iron-ore, ii. 501 
 
 growth of corals, ii. 580, 581, 
 
 591 
 
 Eifel, hot springs of the, i. 396 
 Electricity a source of volcanic heat, ii. 
 
 230, 242 
 
 ETN 
 
 Elephant, covering of fur on, i. 184 
 
 vegetation required for food of the, 
 i. 190 
 
 possible rate of increase of the, ii. 
 317 
 
 remains of extinct, in Sicily and 
 Malta, ii. 342 
 
 Elephants, carcasses of, when imbedded 
 in ice, i. 296 
 
 now a waning group, ii. 337 
 Elevation craters, hypothesis of, i. 633 ; 
 
 ii. 13 
 
 and subsidence of land, causes of, ii. 
 234, 242 
 
 areas of, and of subsidence in Pacific, 
 ii. 603 
 
 Elizabeth or Henderson Island, upraised 
 
 atoll of, ii. 598 
 
 Elsa, K., travertin formed by the, i. 400 
 Embankments of Po and Adige, i. 423 
 England, waste of west coast of, i. 546 
 Eocene fauna and Flora, climate of, i. 
 
 204 
 
 period, ice-action in, i. 209 
 
 map showing geographical changes 
 since the, i. 251 
 
 Epochs, geological, comparative dura- 
 tion of, i. 300 
 
 Epomeo. Mount, in Ischia, i. 601 
 Equatorial current, course of, i. 498 
 Equinoxes, precession of, i. 274 ; ii. 203, 
 
 240 
 
 Equivocal generation, theory of, i. 22 
 Erdmann, Prof. Axel, on rise of land in 
 
 Sweden, ii. 186 
 Erie, currents of Lake, i. 561 
 Erratics, absence of, in equatorial re- 
 gions, i. 109 
 
 and ice-action, 108 
 
 Eruption of Monte Nuovo, i. 608-615 
 Escher, von der Linth, on flood in the 
 Val de Bagnes, i. 353 
 
 Habkeren blocks, i. 210 
 
 glacier motion, i. 370 
 
 Eschricht on migration of Greenland 
 
 whales, i. 286 
 
 Essex, inroads of sea on coast of, i. 521 
 Estuary deposits, imbedding of fresh- 
 water species in, ii. 569 
 Estuaries, silting up of, i. 516 
 
 formation of, i. 566 
 
 Ethiopian character of some N. African 
 mammalia, ii. 341 
 
 region, mammalia of the, ii. 343 
 Etna, rent made in cone of. i. 578 
 
 a glacier under lava on, ii. 38 
 
 ancient valleys of, ii. 40 
 
 antiquity of cone of, ii. 42 
 
 double axis of eruption of, ii. 9 
 
 fossils in lavas of, ii. 510 
 | greenstone dikes in, ii. 9 
 
GENERAL INDEX. 
 
 625 
 
 ETN 
 
 FLO 
 
 Etna, historical eruptions of, ii. 19-31 
 
 lateral cones, obliteration of, ii. 2 
 
 marine Pliocene formations at base 
 of, ii. 5 
 
 recent fossil plants in tuffs of, ii. 6 
 
 section showing double axis of, ii. 12 
 
 state of during Calabrian earthquake, 
 ii. 134 
 
 subterranean caverns on, ii. 24, 31 
 
 towns overflowed by lava of, ii. 22 
 
 Val del Bove on flank of, ii. 7 
 
 view of from Primosole, ii. 4 
 
 truncated cone of, ii. 20 
 
 Euphorbia-feeding beetles of Atlantic 
 
 islands, ii. 416 
 Euphrates, delta of,' advancing rapidly, 
 
 i. 484 
 Europe, Southern, volcanic system of, i. 
 
 596 
 
 small change of level which would 
 unite it with Africa, ii. 342 
 
 European and Negro, amount of differ- 
 ence between, ii. 475 
 
 Evans, Mr., on change of axis of earth's 
 crust, ii. 208 
 
 flint implements in Isle of 
 
 Wight gravel, ii. 562 
 
 Evaporation, currents caused by, ii. 496 
 
 Everest, Rev. R., on climate of fossil 
 elephant,!. 180 
 
 earthy matter brought down 
 
 by Granges, 480 
 
 Excavation of valleys, i. 356; ii. 133, 562 
 
 Excentricity, computations of variations 
 of, i. 292 
 
 of the earth's orbit, i. 269 
 Expansion of rocks by heat, ii. 177, 222 
 Extinction of species, ii. 433 
 a constant work of nature, ii. 
 
 444 
 
 the Dodo, ii. 456 
 
 species by man, ii. 451 
 
 Eye, formation of the, not accounted for 
 
 by natural selection, ii. 491 
 Eyre Sound, glacier of, i. 208 
 
 FALCON rock off Porto Santo, ii. 405, 
 425 
 
 Falconer, Dr., on peat near Calcutta, 
 i. 475 
 
 range of elephant, i. 186 
 
 mammalia of Siwalik Hills, i. 
 
 201 
 
 Falkland Islands, fauna of, i. 220 
 Falloppio on fossil concretions, i. 33 
 Falls of Niagara, i. 358 
 Faluns of Touraine, i. 200 
 Faraday, Mr., on water of Geysers, i. 
 409 
 
 regolation, i. 373 
 
 VOL. II. S S 
 
 Farquharson, Rev. J., on formation of 
 
 ground-ice, i. 367 
 
 Scotch floods, i. 350 
 
 Fault, caused by Calabrian earthquake, 
 
 ii. 122 
 New Zealand earthquake, ii. 
 
 85 
 
 Faults, gradual formation of, i. 120 
 Faunas and Floras of islands, ii. 402 
 Featherstonhaugh on Red River swamps, 
 
 i. 45 
 
 Felspar, decomposition of, i. 410 
 'Feral' varieties never entirely revert 
 
 to old form, ii. 304 
 Fergusson, Mr., on ' the Swatch of no 
 
 ground,' i. 476 
 
 formation of jheels, i. 478 
 
 Ferns, preponderance of, in Coal period, 
 
 i. 226 
 
 Ferrara on Sicilian earthquake, ii. 113 
 Ferruginous springs, i. 410 
 Fife, destruction of coast in, i. 509 
 Fir, upright stumps of, in Bournemouth 
 
 peat, ii. 530 
 trunks in Danish peat mosses, ii. 
 
 500 
 Fish, fluviatile fossil, of Vicksburg, i. 
 
 464 
 
 fossil, their bearing on progres- 
 sion, i. 153 
 
 number of British species in Devo- 
 nian, i. 154 
 
 found alive in Artesian wells, i. 393 
 
 migration and distribution of, ii. 369 
 Fisherton, near Salisbury, fossils of drift 
 
 at, ii. 563 
 
 Fishes, number of known species of, ii. 
 271 
 
 Fishing-hut buried in marine strata, ii. 
 187 
 
 Fissures, caused by Calabrian earth- 
 quake, ii. 122, 124 
 
 preservation of organic remains in, 
 ii. 514 
 
 Fitton, Dr., on English Geology, i. 61 
 Fitzroy, Capt., on earthquakes in Chili, 
 
 ii. 90 
 
 Flamborough Head, waste of, i. 509 
 Fleming, Dr., on fossil elephant, i. 187 
 range of animals as proofs of 
 
 climate, i. 178 
 supposed evidence of former 
 
 tropical climate, i. 215 
 on extirpation of species by 
 
 man, ii. 454 
 migration of turtles, ii. 365 
 
 on stranding of Cetacea, ii. 572 
 Floods, animals drowned in, ii. 537- 
 
 539 
 
 by bursting of lakes, i. 454 
 of Scotland, i. 349 
 
626 
 
 GENERAL INDEX. 
 
 FLO 
 
 Floods of N. America, i. 351 
 
 Bagnes valley, i. 352 
 
 Tivoli, i. 354 
 
 Floras and Faunas of islands, ii. 402 
 
 Flysch, blocks enclosed in, i. 209 
 
 Folkestone, encroachments of sea at, i. 
 528 
 
 Forbes, J.D., on motion of glaciers, i. 
 370 
 
 rainfall in Norway, i. 330 
 
 thickness of lava in Pompeii, 
 
 i. 641 
 
 snow-line in northern hemi- 
 sphere, i. 240 
 
 heat of Gulf-stream, i. 245 
 
 fluid lava, 625 
 
 temple of Serapis, ii. 173 
 
 Edward, on climate of the drift, i. 
 193 
 
 fossilisation exceptional, i. 1 50 
 
 extension of arctic fauna, i. 297 
 
 present distribution of animals 
 
 and plants proving a Glacial period, 
 
 i. 198 
 former junction of Atlantic 
 
 islands with Europe, ii. 406 
 
 origin of gulf-weed, ii. 392 
 
 migration of mollusca, ii. 372, 
 375 
 
 < shells at great depths in the 
 
 sea, ii. 576 
 a pig's power of swimming, ii. 
 
 356 
 -. shells of White Island, San- 
 
 torin, ii. 68 
 Forchhammer, Dr., on boulder drifted 
 
 by ice, i. 385 
 chemical changes in fossil 
 
 algse, ii. 571 
 
 formation of peat, ii. 497 
 
 Forests submerged, i. 462-544 
 
 whether by attraction of ice, i. 290 
 
 effects of the felling of, ii. 452 
 Forfar shire, marl lakes of, ii. 609 
 Forshey, Mr., on curves of Mississippi, i. 
 
 443 
 
 area of Mississippi delta, i. 458 
 
 mud-island of Mississippi, i. 450 
 
 Forster, Mr., on coral reefs, ii. 584 
 nutmeg in pigeon's craw, ii. 
 
 395 
 Fortis on Italian geology, i. 62 
 
 and Testa on fossil fish, i. 65 
 Fossiliferous series, causes of breaks in, 
 
 i. 317 
 
 strata, table of, i. 139 
 
 Fossil shells, height of, in Alps, Andes, 
 and Himalaya, 144 
 
 early speculations concerning, 34-38 
 Fossils, in alluvial deposits and caves, 
 
 ii. 511. See Organic Remains. 
 
 GEF 
 
 Fouque", M., on chemical action in vol- 
 
 canos, ii. 233 
 hydrogen in volcanic eruptions, 
 
 ii. 224 
 Fox, Mr., on electric currents in earth's 
 
 interior, ii. 230 
 
 heat in Cornwall mine, ii. 
 
 205 
 
 Fracastoro, views of, i. 31 
 France, waste of coast in, i. 547 
 Franconia, caves of, ii. 519 
 Franklin, Dr., on whirlwind in Mary- 
 land, ii. 389 
 
 Freshwater plants fossilised, ii. 565 
 Freyberg, school of, i. 68-72 
 Fries on minute sporules of a fungus, 
 
 ii. 387 
 
 Fringing reefs of coral, ii. 593 
 Fuchsel, 1762, opinions of, i. 63 
 Fundy, Bay of, wave called the ' bore/ 
 
 in, i. 560 
 
 rain-prints in, i. 334 
 
 submerged forest in, ii. 532 
 
 pALAPAGOS Archipelago, reptiles 
 VJ of, i. 221 
 
 peculiar species of land-birds in, ii. 
 415 
 
 Gallionellaferruginea, forming bog iron- 
 ore, ii. 501 
 
 Galongoon, eruption of, ii. 56 
 
 Gambier, volcanic island bordered by 
 coral, ii. 574, 590 
 
 Ganges, Artesian borings in delta of, i. 
 478 
 
 and Brahmapootra, mud of, i. 571 
 
 antiquity of delta of, i. 480 
 
 delta of the, i. 470 
 
 deposits in delta of, i. 474 
 
 islands formed by, i. 472 
 
 sediment brought down by, i. 481 
 
 animals drowned in the, ii. 538 
 
 bones of men found in delta of, ii. 
 544 
 
 Gaps, causes of, in fossiliferous strata, 
 i. 318 
 
 in the records of creation, ii. 462 
 Gartner, on crossed varieties of plants, 
 
 ii. 292 
 
 hybrid plants, ii. 308 
 
 Gases, expansive power of liquid, ii. 222 
 Gastaldi on Miocene blocks of the Su- 
 
 perga, i. 206 
 Gaudry, on gradations between fossil 
 
 and living mammalia, ii. 481-484 
 
 structural relationship of fossil and 
 living quadrumaua, ii. 484 
 
 Gay-Lussac, M., on hydrogen in volca- 
 nic eruptions, ii. 224 
 Gene, rise of land near, ii. 188-190 
 
GENERAL INDEX. 
 
 627 
 
 GEI 
 
 Geikie, A., on second advance of gla- 
 ciers, i. 196 
 Gemmellaro on Etna eruption, i. 357 
 
 glacier under lava, ii. 38 
 
 modern eruptions of Etna, ii. 28- 
 
 30 
 
 double axis of Etna, ii. 9 
 Generation, alternate, ii. 327 
 Generelli's illustrations of Lazzaro 
 
 Moro's views, i. 52-56 
 Geneva, Lake, delta of Rhone in, i. 
 
 417 
 
 sediment deposited in, i. 308 
 
 Geographical causes of change of climate 
 
 more influential than astronomical, 
 
 i. 273 
 
 predominant in affecting climate, 
 i. 283 
 
 distribution of fossil mammalia, ii. 
 333 
 
 animals, ii. 329. $ee Regions. 
 
 man, ii. 464 
 
 plants, ii. 381 
 
 provinces of animals, ii. 335 
 Geography, changes of, in Secondary 
 
 and Primary periods, i. 255 
 
 former changes of, how affecting cli- 
 mate, i. 261 
 
 changes of, revealed by geology, i. 
 248 
 
 since the Glacial period, i. 250 
 
 Eocene period, i. 251 
 
 Geological epochs, dates and duration 
 of, i. 300 
 
 Society of London founded, i. 86 
 Geology, modern progress of, i. 87-89 
 
 distinct from Cosmogony, i. 4 
 
 historical progress of, i. Chaps. II. 
 to V. 
 
 speculative tendency of early, i. 324 
 
 defined, i. 1 
 
 compared to History, i. 2, 4, 92 
 
 new school of, i. 85 
 
 prejudices which have retarded, i. 90 
 Georgia, U.S., new ravines formed in, 
 
 i. 344 
 
 South. See South Georgia. 
 Gerbanites, theory of, i. 22 
 
 German Ocean, shoals and valleys in, i. 
 
 568 
 
 Gesner on petrifications, i. 60 
 Geysers of Iceland, i. 409 ; ii. 15 
 cause of their intermittent action, ii. 
 
 218, 221 
 
 view of Icelandic, ii. 216, 217 
 Gibraltar, Straits of, i. 562 
 
 lards' bones in breccia at, ii. 522 
 Glacial epoch, i. 194 
 
 changes of level, since, i. 194 
 
 period, temperature of, i. 288 
 possible dates of, i. 291-296 
 
 GRA 
 
 Glacial period, comparative duration of, 
 i. 300 
 
 species living before and after, 
 
 identical, i. 313 
 
 enduring through all phases of 
 
 precession, i. 281 
 
 hypothesis of greater mean warmth 
 
 in, i. 288 
 
 periods have not recurred periodi- 
 cally, i. 299 
 
 Glacier, moraines of, i. 368 
 
 supposed, at mouth of Amazons, 
 Agassiz on, i. 468 
 
 view of, with moraines, i. 368 
 lake of Switzerland, i. 376 
 
 preserved under lava, ii, 38 
 
 in lat. 46 40' S. in Eyre Sound, i. 208 
 Glaciers, motion of, i. 369-371 
 
 near the sea in New Zealand, i. 21 1, 
 224 
 
 of Alps receding before 10th century, 
 i. 278 
 
 carrying and scoring power of, i. 374, 
 375 
 
 Glen Tilt, granite veins of. i. 75 
 Gmelin on distribution offish, ii. 371 
 Godman, Du Cane, Mr., on birds driven 
 
 by gales, ii. 413 
 migrations of reindeer, ii. 
 
 361 
 God win- Austen, Mr., on stones drifted 
 
 by ice, i. 218 
 
 current deposits, i. 572 
 
 on valley of English Channel, 
 
 i. 532 
 Porlock Bay submerged forest, 
 
 i. 545 
 Gold-fish, varieties of, brought about by 
 
 Chinese, ii. 296 
 Golden age, doctrine of, whence derived, 
 
 i. 13 
 
 Goodwin Sands, i. 525 
 Goose, wild, fossil eggs of, near Salis- 
 bury, ii. 563 
 Goppert, Prof., on mineralisation of 
 
 plants, ii. 533 
 Gould, Captain, survey of Mississippi 
 
 delta, 1764, i. 461 
 Graah, Capt., on sinking of west coast 
 
 of Greenland, ii. 196 
 Graham Island, formed in 1831, ii. 58 
 views of, ii. 60 
 
 Mrs., on earthquake in Chili, ii. 94, 
 96 
 
 Granite, disintegration of, i. 413 
 
 formed at different periods, i. 142 
 
 veins observed by Hutton in Glen 
 Tilt, i. 75 
 
 of the Hartz, Werner, on, i. 70 
 Grant, Capt., on earthquake of Cutch, 
 
 ii. 102 
 
 682 
 
628 
 
 GENERAL INDEX. 
 
 GRA 
 
 HEE 
 
 Graves, Mr., on extirpation of species 
 by man, ii. 456 
 
 Great Britain, indigenous animals ex- 
 tirpated in, ii. 454 
 
 Great Dismal Swamp, Virginia, ii. 505 
 
 Greece, traditions of deluges in, i. 594 
 
 earthquakes in, i. 592 
 
 Greek Archipelago, volcanos of the, i. 
 
 592 
 Greeks, geology of, i. 14-23, 
 
 their ignorance of neighbouring 
 countries, ii. 481 
 
 Green, Colonel, on fossil fish of Vicks- 
 
 burg, i. 464 
 Greenland, sinking of land in, i, 131 
 
 why colder than Lapland, i. 237 
 
 modern subsidence in part of, ii. 196 
 Grimaldi on subsidences caused by Ca- 
 
 labrian earthquake, ii. 121, 132 
 Groins described, i. 531 
 
 effects of, i. 566 
 
 Grotto del Cane, carbonic acid in, i. 411 
 Ground-ice, i. 366 
 
 transporting rocks in Baltic, i. 385 
 
 Growth, correlation of, ii. 314 
 Guadaloupe, fossil man skeletons from, 
 
 ii. 544 
 
 Guatemala, active volcanos in, i. 583 
 Guidotti, Professor, cited, i. 199 
 Guilding on migration of reptiles, ii. 
 
 366 
 
 Guinea, current of gulf of, i. 500 
 Guiscardi, Signor, on stony beds of Som- 
 
 ma, i. 638 
 
 cited, i. 634 
 
 Gulf-stream, causes and velocity of, i. 
 409-501 
 
 course and warming effects of, i. 
 
 244 
 
 Gulholmen, rise of land near, ii. 188 
 
 Giinther, Dr., on range of reptiles, i. 
 229 
 
 tropical character of snakes, 
 
 ii. 343 
 
 marine fish of Pacific and Ca- 
 ribbean sea. ii. 370 
 
 on number of species of fish, ii. 271 
 Guyot, M., on glacier motion, i. 371 
 Gyrogonites described, ii. 566 
 
 HAARLEM, land gained from lake of, 
 i. 552 
 
 Habitation of plants described, ii. 383 
 Habkeren blocks, disputed origin of, i. 
 
 209 
 
 Hal, Captain B., on flood of Bagnes, i. 
 353 
 
 trade winds, i. 497 
 
 waste of Mississippi banks, 
 
 i. 444 
 
 Hall, Captain B., on snags of Mississippi) 
 i. 446 
 
 temple of Serapis, ii. 170 
 
 Sir James, experiments on rocks, i, 
 75 
 
 Mr. James, on geology of New York, 
 i. 359, 361 
 
 Hamilton, Mr. W. J., on volcanos in 
 Smyrna, i. 522 
 
 Sir C., on submergence of Port Royal, 
 ii. 161 
 
 Sir W., on formation of Monte Nuovo, 
 i. 607, 617 
 
 Herculaneum, i. 646 
 
 Vesuvian eruption, 1779, i. 
 
 622 
 
 Calabrian earthquake, ii. 1 25 
 
 temple of Serapis, ii. 167 
 
 Hampshire, waste of coast in, i. 530 
 
 drift, Palaeolithic implements in, ii. 
 560 
 
 submarine forest on coast of, ii. 529 
 Harris, Archdeacon, on Hampshire sub- 
 marine forest, ii. 529 
 
 sunk vessel near Poole, ii. 547 
 
 Hartt, Mr., on Devonian insects, i. 157 
 Hartung, G., on ice-borne rocks in 
 Azores, ii. 420 
 
 eruption of Lancerote, ii. 65 
 
 Hartz Mountains, granite of, i. 70 
 Harwich, waste of cliffs, i. 521 
 Hastings, wearing away of coast near, 
 
 i. 529 
 
 Hatfield Moss, trees found in, ii. 499 
 Head, Sir Edmund, on temple of Sera- 
 pis, ii. 166 
 
 Heat, cause of diffusion over the globe, 
 i. 234 
 
 measurement of in space, i. 278 
 
 whether gradual decline of, on globe, 
 i. 303 
 
 a cause of change of level of temple 
 of Serapis, ii. 177 
 
 increasing with depth, ii. 204, 241 
 
 theory of central, ii. 205, 241 
 
 supposed secular loss of in solar sys- 
 tem, ii. 213 
 
 Heath, Mr., D.D., on effect of polar ice- 
 cap, i. 291 
 
 Hecla, eruptions of, ii. 48 
 
 Hector, Dr., on sudden melting of New 
 Zealand snows, i. 241 
 
 Heer, Professor, on fossil zamia, i. 218 
 
 on character of CEninghen flora, ii. 
 418 
 
 Miocene flora of Madeira, ii. 406 
 
 on arctic Miocene fossil trees, i. 2 03 
 
 coal fossils of Melville Islands, i. 
 225 
 
 Interglacial period, i, 196 
 (Eninghen flora, i. 200 
 
.GENERAL INDEX. 
 
 629 
 
 HEE 
 
 HOP 
 
 Heer, Professor, on Surturbrand of Ice- 
 land, i. 202 
 
 wide-seeding of cryptogamous 
 plants, i. 116 
 
 on plants and animals of Swiss 
 
 lake-dwellings, ii. 287 
 
 Heligoland and Sandy Island, view of, i. 
 555 
 
 inroads of sea on, i. 554 
 
 Helmet, incrustations on a submerged, 
 ii. 550 
 
 Henderson on eruption of Skaptar Jokul, 
 ii. 49, 51 
 
 Icelandic Geysers, ii. 216 
 
 Hennepin and Kalm on Niagara Falls, 
 i. 360 
 
 Hennessy on changes in the earth's fi- 
 gure, ii. 202 
 
 Herbert, Mr., on wild hybrids, ii. 324 
 
 Herculaneum, i. 646 
 
 mass enveloping, i. 640 
 
 objects discovered in, i. 647 
 Herne Bay, waste of cliffs in, i. 523 
 Herodotus on marine fossils of Nile, 
 
 i.9 
 Herschel, Sir J., on climate affected by 
 
 astronomical causes, i. 269, 270 
 
 his drawing of Botzen earth- 
 pillars, i. 331 
 
 heating effect of land under 
 
 sunshine, i. 276 
 light and heat received by 
 
 the earth, i. 270 
 temperature of space, i. 
 
 297 
 
 theoretical difference of cli- 
 mate north and south of the equator, 
 
 i. 277 
 variation of obliquity of 
 
 ecliptic, i. 282 
 
 height of Etna, ii. 1 
 
 his theory of Geysers, ii. 218 
 
 on form of the earth, ii. 200 
 
 germination of boiled seeds, 
 
 ii. 390 
 his hypothesis of the cause of 
 
 volcanos, ii. 229 
 on magnetic storm 1859, ii. 
 
 231 
 flexibility of earth's crust, 
 
 ii. 229 
 
 Sir W., on motion of earth through 
 space, i. 302 
 
 original fluidity of the earth, 
 
 ii. 199 
 Hewitt, Captain, on channel formed by 
 
 shifting of sand-banks, i. 517 
 Hibbert, Dr., on blocks washed out of 
 
 Shetland Isles, i. 503, 505 
 Hilaire, Geoffroy St., on rudimentary 
 
 organs, ii. 273 
 
 Hilaire, Geoffroy, St., on transmutation 
 
 of species, ii. 246 
 
 Hilgard on ' Coast-Pliocene ' of Missis- 
 sippi delta, i. 448, 460 
 
 fossil remains of New Orleans 
 
 Artesian well, i. 459 
 Himalaya, height of fossil shells in, i. 
 
 144 
 
 Hindoo cosmogony, i. 6 
 Hindostan, earthquake of 1762,ii. 146 
 Hippopotamus, teeth of fossil, in banks 
 
 of Nile, in Nubia, i. 438 
 Hoff, Von, on level of Caspian, i. 28 
 Hoffmann on lava of Vesuvius, i. 627 
 Holbach against alluvial theory, i. 50 
 Holland, inroads of the sea in, i. 552-557 
 
 submarine peat in, ii. 571 
 Hollows, funnel-shaped, formed ' by 
 
 earthqxiake, ii. 128 
 Holy head, submerged peat-bed at, i. 
 
 545 
 Hooke on duration of species, i. 41, 42 
 
 his diluvial theory, i. 44 
 
 on fossil turtles implying high tem- 
 perature, i. 174 
 
 Hooker, Dr., on blocks carried by ice- 
 bergs, i. 382 
 
 ' feral ' plants retaining traces 
 
 of cultivation, ii. 305 
 
 delta of Ganges, i. 470-477 
 
 rain in India, i. 330-332 
 
 snow checking radiation of 
 
 heat, i. 285 
 
 apparent immutability of spe- 
 cies, ii. 283 
 
 Algae, ii. 386, 391 
 
 cause of survival of Miocene 
 
 types in Atlantic islands, ii. 419 
 
 changes which are wrought by 
 
 man among species in St. Helena, ii. 
 453, 462 
 
 Crustacea, &c., living at great 
 
 depths in the sea, ii. 577 
 
 drifted seaweed, ii. 393 
 
 Himalayan plants, ii. 319 
 
 insular floras, ii. 417 
 
 number of species of plants, ii. 
 
 271 
 
 useful native Australian plants, 
 
 ii. 286 
 
 variation and selection in the 
 
 vegetable world, ii. 282 
 
 Sir W., on a fox drifted to an island 
 off Iceland, ii. 449 
 
 Hopkins on change of climate from geo- 
 graphical causes, i. 261 
 
 glacier motion, i. 372 
 
 heat received by earth in passing 
 
 through space, i. 302 
 
 thickness of earth's crust, i. 129 ; 
 
 ii. 203, 240 
 
630 
 
 GENEKAL INDEX. 
 
 HOP 
 
 ICE 
 
 Hopkins on action of earthquake wave, 
 
 ii. 139 
 
 Horner, Mr., on thickness of Nile mud, 
 i. 434 
 
 Icelandic geysers, ii. 220 
 
 Horsburgh on icebergs in low latitudes, 
 
 i. 246 
 Horse-tribe, gradational extinct forms 
 
 of, ii. 483 
 
 Horses now a waning group, ii. 337 
 Horsfield, Dr., on earthquakes in Java, 
 ii. 146 
 
 mydaus of Java, ii. 359 
 
 Houses buried in alluvial deposits, ii. 
 
 512 
 Hubbard on floods of North America, i. 
 
 3-52 
 Hue, M., on yaks frozen in ice in Tibet, 
 
 i. 190 
 
 Huggins on spectrum analysis of a va- 
 riable star, i. 303 
 
 Human remains, their durability, i. 166 
 in caves contemporary with ex- 
 tinct quadrupeds, ii. 521 
 
 rock at Guadaloupe, ii. 544 
 
 peatmosses, ii. 501 
 Humber, ' warping' of the, i. 570 
 Humboldt on average rainfall, i. 329 
 
 carcasses frozen in mud, i. 189 
 
 Cumana earthquake, i. 11 
 
 his definition of volcanic action, i. 
 577 
 
 on diffusion of heat over the globe, 
 i. 234 
 
 loss of heat in southern hemi- 
 sphere, i. 284 
 
 migration of animals, i. 179 
 
 thickness of snow on Alps, i. 287 
 
 Botanical regions, ii. 382 
 
 earthquake of Lisbon, ii. 148 
 
 eruption of Jorullo, ii. 53 
 
 insects driven to great heights by 
 
 the wind, ii. 379 
 migration of animals from specific 
 
 centres, ii. 336 
 migration of American waterfowl, 
 
 ii. 364 
 
 origin of gulf- weed, ii. 392 
 
 spread of domestic cattle in the 
 
 Pampas, ii. 458 
 Humphreys, General, on Mississippi, i. 
 
 449 
 Humphreys and Abbot, MM., report on 
 
 Mississippi, i. 442-445 
 sediment carried down by 
 
 Mississippi, i. 453-458 
 Hunt, Mr T. Sterry, on petroleum, i. 41 3 
 Hunter, John, on hybrids, ii. 306 
 multiple origin of the dog, ii. 
 
 293 
 Hurst Castle shingle bank, i. 531 
 
 Hutchinson, John, his Moses's Principia, 
 i. 49 
 
 Hutton distinguished Geology from Cos- 
 mogony, i. 4 
 
 theory of, 73, 74-77, 83 
 
 on original formation of the earth, ii. 
 200 
 
 Huxley on origin of Ancon sheep, ii. 
 
 312 
 
 term 'Natural Selection,' ii. 318 
 
 six-fingered variety of man, ii. 
 
 477 
 
 Hybrid wild plants, ii. 324 
 Hybridisation of animals and plants, ii. 
 
 305 
 Hybridity will not account for special 
 
 instincts, ii. 325 
 Hybrids of canine species, ii. 306 
 
 between horse and ass, ii. 306 
 
 powerless in the struggle for exist- 
 ence, ii. 310 
 
 Hydrogen present in volcanic eruptions, 
 
 ii. 224 
 Hypogene rocks, i. 144 
 
 ICE, animals imbedded in, i. 296 
 floating in sea of white chalk, i. 
 216 
 
 solid matter transported by, i. 363 
 
 thickness and extent of polar, i. 285 
 
 action and erratics, i. 108 
 
 in Eocene period, i. 209 
 
 in Miocene times, i. 205 
 
 supposed, in Permian period, i. 
 
 222 
 in Devonian period, i. 231 
 
 transportation of rocks by, in Baltic, 
 ii. 182 
 
 Iceberg, seen off Cape of Good Hope, i. 
 246 
 
 carrying a mass of rocks, i. 381 
 Icebergs, a means of conveying seeds to 
 
 islands, ii. 419 
 
 carrying blocks, i. 379 
 
 floating south, a cause of cold, i. 245 
 Ice-cap, probable thickness of polar, i. 
 
 288 
 
 on pole, affecting the level of the 
 ocean, i. 272, 285, 289 
 
 Ice-caps at both poles, in the Glacial 
 period, i. 282 
 
 effect of, on the level of the ocean, 
 i. 289, 290 
 
 Ice-floes, drifting of animals on, ii. 160 
 Ice-streams in Baffin's Bay, i. 288 
 Iceland, icebergs stranded on, i. 245 
 
 increase of reindeer imported into, 
 ii. 450 
 
 geysers of, i. 409 ; ii. 215 
 
 Miocene strata of, i. 201 
 
GENEEAL INDEX. 
 
 631 
 
 ICE 
 
 JON 
 
 Iceland, new island near, ii. 49 
 
 Surturbrand and fossil plants of, i. 
 202 
 
 supposed effects of first polar bear 
 entering, ii. 448 
 
 volcanic eruptions in, ii. 48 
 Ichthyosaurus in lias, lat. 77 N., i. 219, 
 
 232 
 
 Ictis of Diodorus Siculus, i. 542 
 Igneous action. See Volcanic. 
 
 conservative power of, ii. 238, 
 
 243 
 
 and aqueous forces, counterbalancing 
 and antagonistic effects of, ii. 97, 237, 
 243 
 
 forces, supposed former intensity of, 
 i. 117 
 
 rocks, nature of subterranean, ii. 77 
 Imbedding of reptiles, insects, and birds, 
 
 ii. 533, 534 
 
 of terrestrial quadrupeds, ii. 535 
 India, buried houses and cities in, ii. 
 
 512 
 Indian region of mammalia, rise of land 
 
 which would unite all the islands of 
 
 the, ii. 346 
 Indus, changes of level in delta of the, 
 
 ii. 99 
 
 map of the, ii. 98 
 
 sinking of delta of, ii. 177 
 Infusorial tuff of Pompeii, i. 644 
 Inland seas, deltas of, i. 417, 420, 421 
 Inorganic causes of change, i. 327 
 Inquisition, effect of, in retarding the 
 
 intellectual progress of a nation, ii. 
 
 489 
 Insect-destroying animals in Paraguay, 
 
 ii. 337 
 Insects in Devonian strata, i. 157 
 
 agency of, in preserving equilibrium 
 of species, ii. 436 
 
 number of British insects known 
 (1833), ii. 271 
 
 of Atlantic islands chiefly indigenous, 
 ii. 415 
 
 distribution and migration of, ii. 377 
 
 fertilisation of plants by, ii. 309 
 
 imbedding of, ii. 533 
 
 of Chili some of northern species, ii. 
 337 
 
 Instincts, hybridity will not account for 
 special, ii. 325 
 
 inherited, of dogs, ii. 294 
 
 of migration, ii. 357 
 'Insular' climates, i. 239 
 
 "Faunas and Floras, ii. 402 
 Inter-glacial periods, i. 195 
 
 Ireland, bursting of peat mosses in, ii. 
 504 
 
 peat with buried hut in, ii. 504 
 Iron, melting point of, ii. 207 
 
 Iron-ore, sources of bog, ii. 501 
 Ischia, view of volcanic rocks of, i. 601 
 
 hot springs of, i. 409 
 
 volcanic eruptions of, i. 598, 605 
 
 earthquake of 1828 in, ii. 93 
 Island, new, in Mediterranean, 1707, i. 
 
 51 
 
 mode of peopling with landshells, ii. 
 429 
 
 Islands, destruction of, in Baltic, i. 554 
 
 on coast of Scotland, i. 506 
 
 formed by Granges, i. 472 
 
 floating, of driftwood, ii. 361 
 
 floras and faunas of, ii. 402 
 
 of Atlantic, age and origin of, ii. 
 403 
 
 some originally uninhabited by man, 
 ii. 466 
 
 the peopling of, accords with theory 
 of variation and natural selection, ii. 
 431 
 
 Isle of Wight, waste of its shores, i. 
 
 530 
 Isothermal lines, their curves in Europe 
 
 and America, i. 236, 239 
 Isothermals, map of mean annual, i, 
 
 238 
 
 deflection of, in Glacial period, i. 
 297 
 
 Italy, alternation of earthquakes between 
 Syria and, i. 594 
 
 Pliocene strata of, i. 199 
 
 early geologists of, i. 30, 50 
 Ivory, vast stores of, in Siberia, i. 185 
 
 JACK, Dr., on coral of Pulo Nias, ii. 
 605 
 Jamaica, earthquake in, 1692, ii. 160 
 
 thickness of Miocene coral in, ii. 
 607 
 
 James, Sir Henry, on Dead Sea level, i. 
 
 112 
 block of tin dredged up in 
 
 Falmouth harbour, i. 541 
 Jamieson, Mr., of Ellon, on glacier-lake 
 
 theory, i. 379 
 Japan, Indian character of snakes in, ii. 
 
 343 
 Java, valley of poison in, i. 589 
 
 volcanos in, i. 589 ; ii. 56 
 
 earthquakes in, ii. 105, 113, 145, 
 158 
 
 river floods in, ii. 538 
 
 and Sumatra, zoological connection 
 between, ii. 346 
 
 Jeffreys, J.Grwyn, on English landshells, 
 
 ii. 427 
 
 littoral deposit under marine 
 
 strata in Sweden, ii. 192 
 Jones, Sir "W., on Menu's institutes, 
 
632 
 
 GENERAL INDEX. 
 
 JOE 
 
 LAN 
 
 Jorullo, eruptions of, i. 584; ii. 53 
 no recent eruptions of, ii. 56 
 Juan Fernandez, earthquake at, ii. 154 
 Jukes, Mr., on volcanic islands near 
 
 Java, i. 589 
 
 coral reef, ii. 605 
 
 Junghuhn on eruptions of Java, ii. 11, 
 
 40 
 Papandayang volcanic eruption, 
 
 ii. 146 
 Jutland, inroads of sea in, i. 556 
 
 TTAMTSCHATKA, volcanos in, i. 588 
 J\. Kaschnitz, Herr Von, on destruc- 
 tion of earth-pillars by rain, i. 339 
 Kaswini on oscillations of land and sea, 
 
 i. 29 
 
 Katavothra of Greece, ii. 517 
 Kaup, Dr., on gibbon, or long-armed 
 
 ape, i. 200 
 
 Kaye, C. J., on Indian fossils, i. 213 
 Keilhau, Prof., on rise of land in Nor- 
 way, ii. 195 
 
 Keill on Whiston and Burnet, i. 49 
 Kent, inroads of sea on coast of, i. 522 
 Kentucky, caves in limestone, ii. 514 
 Keyserling, Count, map of Russia, i. 
 
 251 
 King, Capt., on coral reefs, ii. 597 
 
 Mr., on submerged cannon, ii. 549 
 
 Rev. S. W., on Eccles Church, i. 
 513 
 
 Kinnordy, Loch of, insects in marl of, ii. 
 533 
 
 canoe in peat of, ii. 548 
 
 Kirby and Spence on insect instincts, ii. 
 326 
 
 insects preserving balance 
 
 of species, ii. 437, 438, 441 
 Kirwan, his geological essays, i. 82 
 Kolreuter on hybrid plants, ii. 307 
 Konig, Mr., on Guadaloupe human skele- 
 tons, ii. 545 
 
 Koran, cosmogony of the, i. 28 
 Kotzebue on drifted canoe, ii. 467 
 Kurile Isles, active volcanos in, i. 588 
 
 T ABRADOR, rocks drifted by ice on, 
 JJ i. 384 
 
 Laccadive Islands, coral reefs of, ii. 588 
 Lac6pede on mummies from Egypt, ii. 
 
 264 
 
 Lagoons of coral islands, ii. 599 
 Lagrange on limits of excentricity of 
 
 earth's orbit, i. 269 
 Lake, dammed up by a glacier, i. 376 
 deltas, i. 417, 421 
 dwellings, plants and animals of, ii. 
 
 285, 287 
 
 Lakes, new, formed during earthquakes 
 
 in New Madrid, ii. 109 
 during Calabrian earthquake, 
 
 ii. 127 
 
 formed in Louisiana, i. 454 
 Lamarck, his theory of progression, i. 
 
 147 
 
 on Egyptian mummies, ii. 265 
 
 rudimentary organs, ii. 274 
 
 slowness of geological change, ii. 
 
 266 
 
 conversion of orang into man, ii. 
 
 257 
 
 his definition of species, ii. 246 
 
 sketch of his theory of transmutation 
 of species, ii. 246-260 
 
 Lancerote, eruption of, ii. 64 
 Land, effect of, in distributing heat, i. 
 276 
 
 effect of, in warming the atmosphere, 
 i, 237, 241 
 
 height of, compared to depth of sea, 
 i. 265 
 
 map showing antipodal, i. 258 
 
 now abnormal in quantity at the 
 poles, i. 247 
 
 proportion of, to sea in tropics, i. 
 247 
 
 position of, which would favour warm 
 climate, i. 248 
 
 rise of, in Sweden, i. 121, 133 
 
 rise and depression of, i. 24 
 
 and sea, present unequal distribution 
 of, i. 257 
 
 causes of elevation and subsidence 
 of, ii. 234, 242 
 
 balance of dry, how preserved, ii. 237 
 
 permanent upheaval and subsidence 
 of, in New Zealand, ii. 85 
 
 elevation and subsidence of, without 
 earthquakes, ii. 180 
 
 rise of, in Sweden, ii. 180-196 
 
 shells, age of fossil, in Atlantic is- 
 lands, ii. 425 
 
 of Atlantic islands nearly all in- 
 digenous, ii. 421 
 
 modes in which they may reach 
 
 oceanic islands, ii. 429 
 
 of Great Britain and Atlantic is- 
 lands compared, ii. 426 
 
 Landslip in Dorsetshire, i. 536 
 
 Landslips on the Amazons, i. 469 
 
 floods caused by, i. 350 
 
 during Calabrian earthquake, ii. 130- 
 133 
 
 imbedding of organic remains by, ii. 
 513 
 
 Languages, plurality of, among rude 
 tribes, ii. 480 
 
 origin of, compared to that of species, 
 ii.470 
 
.GENERAL INDEX. 
 
 633 
 
 LAP 
 
 MAC 
 
 Laplace on non-contraction of globe, i. 
 
 304 
 
 density of the earth, ii. 202 
 
 Lariviere, M.,on ice-transported blocks, 
 
 i. 364 
 
 Lartet, M., on implements of the Rein- 
 deer period, ii. 559 
 Lassaigne, his analysis of Nile mud, i. 
 
 433 
 Lauder, Sir T. D., on Moray floods, i. 
 
 349 
 
 , floods in Scotland, ii. 5 1 1 
 
 Lava streams, immense volume of, in 
 
 Iceland eruption, ii. 51 
 of Iceland and central France, ii. 
 
 51 
 Lavas of Somma, slope of, i. 632, 638, 
 
 643 
 
 Red-brick, of Madeira, ii. 404 
 
 want of parallelism of, on Etna,ii. 14 
 Lazzaro Moro. See Moro. 
 Leaves, fossil, in tuffs of Etna, ii. 6 
 of Casa dell' Acqua on north side 
 
 of Somma, i. 634 
 Lehman, treatise of 1756, i. 59 
 Leibnitz on origin of primitive masses, 
 
 i. 40 
 
 Leidy on reptiles of the Chalk, i. 214 
 fossil horses of United States, ii. 
 
 337 
 
 Lemming, migrations of the, ii. 358 
 Lemurs, peculiar genera of, in Mada- 
 gascar, ii. 345 
 Lena, fossil bones on banks of, i. 181, 
 
 183 
 
 Leonardo da Vinci on fossil shells, i. 31 
 Leslie, Sir J., on heat received by poles 
 
 and equator, i. 284 
 on temperature of hottest 
 
 month in London, i. 294 
 Level of Dead Sea and Caspian, i. 112 
 
 changes of, in Calabrian earthquake, 
 ii. 120 
 
 Level-Tier's computation of excentricity 
 
 of earth's orbit, i. 270 
 Lewes levels, marine strata containing 
 
 freshwater species at, ii. 569 
 Liebig, Prof., on Icelandic Geysers, ii. 
 
 221 
 
 Light, influence of, on plants, i. 226 
 Lignite, layer of, in San Jorge, Madeira, 
 
 ii. 406 
 
 Lima, elevated marine strata at, ii. 158 
 Lime, whence derived, ii. 608 
 Lincolnshire, waste of coast, i. 511 
 Lindley, Dr., on fossil plants of Melville 
 
 Island, i. 225 
 
 number of species of plants, ii. 
 
 270 
 Linnaeus on dispersion of plants, ii. 386, 
 
 393 
 
 Linnaeus on wild hybrids and protean 
 
 genera, ii. 323 
 
 introduction of species, ii. 330 
 number of species of insects, ii. 
 
 271 
 
 plants dispersed by man, ii. 398 
 
 species, ii. 267 
 
 structure of man and ape, ii. 485 
 
 Lippi on Herculaneum and Pompeii, i. 
 
 643, 646 
 Liquid gases, expansive power of, ii. 
 
 222 
 Lisbon, earthquakes at, i. 596 
 
 earthquake of 1755, ii. 147 
 
 subsidence of quay of, ii. 147 
 Lister on fossil shells, i. 40 
 Livingstone on natives collecting grass- 
 seeds, ii. 286 
 
 Locusts, devastations caused by, ii. 440 
 
 migration of, ii. 380 
 
 seeds carried by, ii. 420 
 Loess of Mississippi Valley, i. 463 
 the Nile, i. 433 
 
 Log-cabin found in peat of Donegal, ii. 
 
 504 
 Lombok and Bali, striking contrast of 
 
 species in, ii. 349 
 London, Artesian well near, i. 389 
 Longmynds, system of, Post-Silurian, i. 
 
 129 
 Louisiana, formation of lakes in, i. 
 
 454 
 Loven and Fries, Profs., cited, ii. 324 
 
 Prof., on rise of land in Sweden, ii. 
 187 
 
 Lowe, Rev. R. T., on Madeiran land- 
 shells, ii. 421 
 
 Lowestoff Ness, Suffolk, how formed, i. 
 518, 519 
 
 Lubbock, Sir J., on deposition of Nile 
 mud, i. 437 
 
 term Neolithic, i. 176 
 
 absence of pottery among 
 
 savages, ii. 479 
 
 weapons of pre-historic 
 
 man, ii. 558-560 
 
 MACACUS PLIOCENUS, doubtful 
 authenticity of, i. 194 
 MacClelland, Dr., on volcanic line in 
 
 Bay of Bengal, i. 590 
 McClintock, Captain, on oolitic fossils 
 
 near the pole, i. 218 
 
 life in deep seas, ii. 577 
 
 Macculloch, Dr., on nature of peat, ii. 
 
 496 
 
 structure of peat, ii. 496 
 
 origin of limestone, ii. 608 
 
 Mackenzie River, floods of, i. 188 
 driftwood of the, ii. 526 
 
634 
 
 GENERAL INDEX. 
 
 MAC 
 
 MAP 
 
 Maclaren, Mr., remarks on theory of 
 atolls, ii. 603 
 
 Macmurdo, Captain, on delta of Indus, 
 ii. 99 
 
 M'Nab, Mr. J., his sketch of an iceberg, 
 i. 381 
 
 Madagascar, a sub-province of Ethio- 
 pian zoological region, ii. 344 
 
 number of peculiar species in, ii. 
 344 
 
 Madeira, birds of, common to Europe, 
 ii. 413 
 
 and Porto Santo, proportion of ex- 
 tinct and living landshells of, ii. 422- 
 426 
 
 Madeiran Archipelago, map of, ii. 405 
 Madrepora muricata, ii. 582 
 Madrid, New. See New Madrid. 
 Maeler Lake in Sweden, ii. 194 
 Magellan, Straits of, tides in, i. 493 
 Magnesia deposited by springs, i. 397 
 Magnetic storm, Sept. 1859, ii. 231 
 Magnetism, solar, i. 303 
 
 a source of volcanic heat, ii. 230, 242 
 Mahomet, his cosmogony, i. 28 
 Maize, modifications produced in the, 
 
 ii. 297 
 
 Majoli on volcanic ejection of shells, 
 i. 35 
 
 Malay Archipelago, great zoological 
 boundary in the, ii. 347 
 
 two marked human races in the, 
 
 ii. 474 
 
 Maldive Islands, coral reefs of, ii. 588 
 
 Mallet, Captain, on Trinidad petroleum, 
 i. 414 
 
 Mallet, Mr. E., on Calabrian earth- 
 quake, ii. 118, 137, 143 
 
 earthquake vorticose move- 
 ment, ii. 120 
 
 earthquakes, ii. 82 
 
 mode of determining the 
 
 earthquake focus, ii. 137 
 
 depth of earthquake focus, 
 
 ii. 139 
 
 sea-waves during earth- 
 quakes, ii. 152 
 
 Malthus, his law of population applied 
 to animals, ii. 279 
 
 Mammalia, absence of, how for affecting 
 reptile life, i. 220 
 
 fossil, as bearing on progression, i. 
 158 
 
 of Mississippi loess, i. 465 
 
 successive appearance of higher, i. 
 163 
 
 absence of, in Atlantic, islands, ii. 
 411 
 
 different regions of, ii. 335, 340, 341, 
 343, 346, 347 
 
 fossil of Pikermi, ii. 482 
 
 Mammalia, geographical relation of fos- 
 sil to living, ii. 332 
 distribution of fossil, ii. 333 
 
 of the Nearctic region, ii. 340 
 imbedding of, in strata, ii. 535 
 
 Mammifer fossil of trias, i. 158 
 Mammifers, number of species of, ii. 271 
 Mammoth, climate of the, i. 178 
 
 Siberian, i. 181 
 
 found fossil on Yenesei, 1866, i. 185 
 
 probable food of, i. 187 
 
 Man, introduction of, and its effects, i. 
 167-173 
 
 durability of bones of, i. 1 66 ; ii. 544 
 
 his agency in dispersing plants, ii. 
 397. 
 
 agency of, in dispersion of animals, 
 ii. 336 
 
 an Old-World type, ii. 474 
 
 cerebral development of, ii. 485, 487 
 
 diverged from one starting point, ii. 
 469 
 
 extirpation of species by, ii. 451 
 
 his origin and distribution, ii. 464 
 
 and horse found in Solway moss, ii. 
 503 
 
 imbedding of his remains and works 
 in subaqueous strata, ii. 541 
 
 modern origin of, ii. 555 
 
 monuments in Europe of pre-historic, 
 ii. 557 
 
 only one of many exterminating 
 agents, ii. 460 
 
 question of multiple origin of, ii. 475 
 
 remains of, in the bed of the sea, ii. 
 542 
 
 remains of, in lowest Danish peat, ii. 
 500 
 
 barbarism of Palaeolithic, ii. 493 
 
 subject to animal laws, ii. 493 
 
 whether his bodily frame varies, ii. 
 471-476 
 
 six-fingered variety of, ii. 476 
 
 whether degraded from a higher or 
 risen from a lower type, ii. 479 
 
 Manetho, i. 92 
 
 Mantell, Dr., on imbedding of insects, 
 ii. 534 
 
 Mr. Walter, on New Zealand earth- 
 quake, ii. 85 
 
 Map of changes on the coast of Holland, 
 
 &c., i. 549 
 
 Holland and the Baltic, i. 557 
 
 Ganges and Brahmapootra, i. 471 
 
 isothermal lines, i. 239 
 
 Mississippi delta, i. 448 
 
 Siberia, i. 182 
 
 volcanic district of Naples, i. 559- 
 
 579 
 volcanos from Philippine Islands 
 
 to Bengal, i. 586 
 
GENERAL INDEX. 
 
 635 
 
 MAP 
 
 MIS 
 
 Map showing position of mud-lumps of 
 the Mississippi, i. 449 
 
 changes in geography since the 
 Eocene period, i. 252 
 
 present unequal distribution of 
 land and sea, i. 258 
 
 ideal, of normal distribution of land 
 and sea, i. 263 
 
 of Calabria, ii. 114 
 Chili, ii. 91 
 
 Cutch, ii. 98 
 
 depth of ocean between Atlantic 
 
 islands and the mainland, ii. 407 
 
 Indian and Australian zoological 
 
 provinces, ii. 347 
 
 Madeira Archipelago, ii. 405 
 
 New Zealand, ii. 84 
 
 Santorin, ii. 66 
 
 Sweden, ii. 184 
 
 Maps, ideal, showing position of land 
 and sea, which might produce ex- 
 tremes of heat and cold, i. 266 
 
 Marine fossils, Greek theories as to, i. 
 19 
 
 alluvium burying fossils, ii. 572 
 
 deposits, freshwater species imbed- 
 ded in, ii. 569 
 
 plants, imbedding of, ii. 571 
 
 reptiles, imbedding of, ii. 573 
 
 strata, mammalia imbedded in, ii. 
 540 
 
 testacea, imbedding of, ii. 574 
 
 upraised strata in Sweden, ii. 192 
 Marjelen See, or glacier-lake, i. 377 
 Marks cut at high-water level in Swe- 
 den, ii. 185, 188 
 Marl lakes of Scotland, ii. 609 
 Marmora, Count de la, on Sardinian 
 
 buried pottery, ii. 563 
 Marsupials of Australia, ii. 332 
 Martius on animals carried on floating 
 
 islands, ii. 362 
 
 Mattioli on fossil organic shapes, i. 33 
 Mauritius, reef uplifted above the level 
 
 of the sea, ii. 606 
 Meandrina labyrinthica, ii. 580 
 Medial moraines, i. 374 
 Mediterranean, depth of, at Nile delta, 
 i. 431 
 
 depths, temperature, and currents of, 
 i. 562 
 
 level of, compared to Eed Sea, i. 
 496 
 
 section of basins of, i. 562 
 
 absence of tides in, ii. 168 
 Medusa, metamorphoses of the, ii. 327 
 Meech on increase of heat by shortening 
 
 of minor axis of earth's orbit, i. 273 
 
 on solar radiation, i. 284 
 
 Megna River, arm of Brahmapootra, i. 
 470 
 
 Melville, Dr., on extinction of the Dodo, 
 
 ii. 457 
 Melville Island, carboniferous fossils 
 
 in, i. 225 
 
 migration of musk-ox to, ii. 361 
 
 Memphis, computation of growth of Nile 
 
 mud at, i. 435 
 Menu's institutes, i. 7, 8 
 Mer de Glace, width of, i. 370 
 Mersey, vessel in bed of, ii. 547 
 Messina, tide in Straits of, i. 493 
 
 subsidence of quay of, ii. 121 
 Metallic substances changed by sub- 
 mersion, ii. 549 
 
 Metamorphic rocks, texture and origin 
 
 of, i. 142 
 Metzger on modifications effected in 
 
 maize, ii. 298 
 
 Mexico, volcanos of, i. 584 ; ii. 53 
 Meyer, H. Von, on reptiles of Trias, i. 
 
 219 
 
 Meyer, Dr., on earthquake in Chili, ii. 95 
 Michell, Rev. J., on earthquakes, i. 61 
 
 on retreat of sea during earthquakes, 
 ii. 150, 152 
 
 Michelotti, M. Jean, on growth of corals, 
 
 ii. 580 
 Microlestes, discovery of, in Upper Trias, 
 
 i. 161 
 Middendorf, M., Calamites found by, 
 
 near mouths of Lena, i. 225 
 
 on Siberian mammoth, i. 184-188 
 
 Migration of birds, ii. 364 
 
 fish, ii. 369 
 
 insects, ii. 377 
 
 quadrupeds, ii. 355-363 
 
 reptiles, ii. 365 
 
 Testacea, ii. 372 
 
 Migratory instincts, ii. 357 
 
 Milford Haven, rise of tides at, i. 494 
 
 Millennium, i. 32 
 
 Miller, Dr. W. A., on spectrum analysis 
 
 of a variable star, i. 303 
 Mineral, character of strata variations 
 
 in, i. 309 
 
 springs, ingredients of, i. 397 
 
 veins, contraction of, explained, ii. 
 125 
 
 Minerals of Vesuvius, i. 632 
 Mineralisation of plants, ii. 532 
 Mines, heat measured by descents in, ii. 
 
 205 
 Miocene fossil trees in arctic latitudes, 
 
 i. 203 
 
 Lower, strata of, i. 202 
 
 Upper, warm climate of, i. 199 
 ice-action in, i. 205 
 
 age of Atlantic islands, ii. 403 
 
 types of plants in Atlantic islands, 
 ii. 418 
 
 Mississippi, basin and delta of, i. 440 
 
636 
 
 GENEEAL INDEX. 
 
 MIS 
 
 NEL 
 
 Mississippi, 'bluffs' of the, i. 462 
 
 colour of, caused by sediment, i. 310 
 
 diagram of banks of, i. 443 
 
 sediment carried down by, i. 458 
 
 curves of the, i. 442 
 
 cuts-offofthe, i. 346 
 
 delta and alluvial plain of, i. 457 
 
 growth of, i. 461 
 section of valley of, i. 464 
 
 Valley, loess of, i. 463 
 
 mud-lumps at mouths of, i. 447 
 sunk country of, i. 456 
 
 velocity of current of, i. 441 
 
 earthquake region of, ii. 107 
 
 floating islands on the, ii. 361 
 
 sinking of plain of, ii. 107 
 Missouri, earthquakes in, ii. 106 
 Moel Tryfaen, recent marine shells on, 
 
 i. 195 
 Mollusks, fossil, as bearing on theory of 
 
 progression, i. 151 
 eggs of attached to floating wood, ii. 
 
 377 
 distribution and migration of, ii. 372 
 
 geographical provinces of, ii. 372 
 imbedding of marine, ii. 574 
 
 mode of diffusion of, ii. 374 
 Moluccas, earthquakes in, 1693, ii. 160 
 
 volcanos of the, i. 585 
 Monads, Lamarck's theory of, ii. 256 
 Mongibello (Etna), axis of eruption of, 
 
 ii. 11 
 
 Monkeys, grades of Eocene and Mio- 
 cene, i. 164 
 
 Monte Bolca, fossil fish of, i. 65 
 
 Minardo, growth and height of lateral 
 cone of on Etna, ii. 45 
 
 Nuovo, formation of, i. 606 
 internal talus of, i. 616 
 
 Sacro, fossil mammoths of, i. 186 
 
 Somma, small range of dikes in, i. 636 
 Montesquieu on the races of man, ii. 
 
 465 
 Monti Eossi, size of, ii. 2 
 
 formation of, ii. 21 
 
 Montlosier on volcanos of Auvergne, i. 
 
 73 
 Moore, J. C., calculations of climatal 
 
 effects of excentricity, i. 293 
 
 on West Indian corals, i. 254 
 effect of polar ice-cap, i. 
 
 291 
 
 Moraines of glaciers explained, i. 374 
 Morayshire, effects of floods in, ii. 511 
 Morea, ceramique of the, ii. 513 
 osseous breccias now forming in the, 
 
 ii. 516 
 
 human remains imbedded in, ii. 517 
 Morlot, M., on subsidence of bed of 
 
 Adriatic, i. 425 
 two glacial periods, i. 196 
 
 Moro Lazzaro, his geological views, i. 
 
 51-56 
 Morton, Dr., on unity of type in Eed- 
 
 Indian, ii. 473 
 
 Moths flying 300 miles from land, ii. 380 
 Mount St. Elias, Santorin height of, ii. 
 
 78 
 Mountain-chains, doctrine of sudden rise 
 
 of, 121-131 
 upheaval and subsidence of, 131- 
 
 138 
 Moya, or fetid mud, from volcano in 
 
 Quito, ii. 112 
 Mozambique current, course of, i. 498 
 
 warming effects of, i. 247 
 
 Mud-lumps of the Mississippi delta, i. 
 
 447 
 views of, i. 450, 451 
 
 currents of, in Calabrian earthquake, 
 ii. 133 
 
 volcanos, ii. 75 
 Mules. See Hybrids. 
 
 Mummies of Egypt identical with living 
 
 species, ii. 263 
 
 Murchison, Sir E. I., on Hartz Moun- 
 tain, i. 71 
 
 map of Eussia, i. 251 
 
 on Habkeren blocks, i. 209 
 
 cited, i. 112, 251, 253 
 
 on extension of Siberia, i. 1 88 
 
 marine strata of Devonian, 
 
 i. 320 
 
 travertin of Tivoli, i. 407 
 
 Murie, Dr., on fossil shells of Nile, i. 438 
 Murray, Mr., on Silver Pits and Dogger 
 
 Bank, i. 569 
 
 Musk-ox, migration of, to Melville Is- 
 land, ii. 361 
 
 Mydaus meliceps confined to high moun- 
 tains in Java, ii. 359 
 Myrmecobius fasciatus, i. 159 
 
 NAPLES, coast of, raised by an erup- 
 tion, i. 44 
 
 volcanic district of, i. 599 
 Narwal, stranded near Boston, ii. 572 
 Natural barriers, the doctrine of, ii. 331 
 
 selection, ii. 316-327 
 
 objections to the theory of, ii. 489 
 
 ultimately secures the prevalence 
 
 of superior forms, ii. 488 
 
 Darwin on, ii. 277-281 
 
 Nearctic region, mammalia of the, ii. 340 
 Nea-Kaimeni, formation of, ii. 67 
 Needles of the Isle of Wight, i. 531 
 Negro, constancy of character for 4,000 
 
 years, ii. 471 
 
 and European, amount of difference 
 between, ii. 475 
 
 Nelson, Lieut., on coral reefs, ii. 605 
 
GENERAL INDEX. 
 
 637 
 
 NEO 
 
 OWE 
 
 Neolithic era, climate of, 177 
 
 period, possible date of, i. 295 
 
 implements of the, ii. 558 
 Neotropical regions of animals, ii. 335 
 Neptunists and Vulcanists, i. 71 
 Nero, Francesco del, on eruption of 
 
 Monte Nuovo, i. 611 
 New Madrid, sunk country of, i. 456 
 
 Caledonian, coral reef surrounding, 
 ii. 592 
 
 Madrid, U.S., earthquake in, ii. 106 
 
 sunk country of, ii. 108 
 
 Zealand, rapid spread of water-cress 
 in, ii. 453 
 
 earthquake of 1855, ii. 82 
 
 glaciers of, i. 211, 224 
 
 ferns in, i. 224 
 
 map of and site of earthquake, ii. 
 84 
 
 absence of indigenous mammalia 
 in, ii. 411 
 
 red sandstone, various ages of, i. 114 
 Newbold, Lieutenant, on mud of Nile, 
 
 i. 431 
 Niagara, recession of Falls of, i. 359 
 
 view of the Falls of, i. 358 
 Nile mud, borings made in, i. 435 
 
 delta of, i. 431 
 
 Nilsson, Prof., on sinking of land south 
 of Stockholm, ii. 190 
 
 migration of eels, ii. 371 
 weapons of Pre-historic man, 
 
 ii. 558 
 Nomenclature geological, defects of, i. 
 
 115 
 Nordenskiold, Prof., on rise of land in 
 
 Sweden, ii. 187 
 
 Norfolk, waste of coast of, i. 511 
 North Cape, rise of land at, i. 133 
 
 whether land now rising at, ii. 195 
 
 Northern hemisphere, former climate of, 
 
 i. 174 
 
 extreme climates of the, i. 276 
 Northstrand, destruction of, by the sea, 
 
 i. 557 
 
 Norway, rise of land in, ii. 195 
 Norwich once situated on an arm of the 
 
 sea, i. 516 
 Nova Scotia, distinct deposits of red 
 
 marl in, i. 114 
 
 rise of tides in, i. 560 
 Nummulitic limestone, climate of, i. 209 
 Nuovo, Monte, internal talus of, i. 616 
 Nyoe, new island formed in 1783, ii. 49 
 
 OBI, River, fossils on shores of, i. 181 
 Obliquity of ecliptic, variation in, 
 i. 282 
 
 Obelisks shaken by Calabrian earth- 
 quake, ii. 119 
 
 Obydos, valley of Amazons, freshwate 1 " 
 
 bivalve shells of, i. 467 
 Ocean, great depth of, a cause of slow 
 
 geographical change, i. 265 
 
 Primaeval, Lamarck's belief in, ii. 
 254 
 
 Oculina hirtella, ii. 582 
 
 Odoardi on tertiary strata of Italy, i. 
 
 62 
 (Eninghen, Upper Miocene flora of, i. 
 
 200 
 
 Oersted on electro-magnetism, ii. 230 
 Ogygian deluge, i. 593 
 Old red sandstone, climate of fossils of, 
 
 i. 230 
 Olivi on deposits in Adriatic, i. 426 
 
 fossil remains, i. 34 
 
 Omar on ' Retreat of the Sea,' i. 28 
 Oolite fossils, climate of, 218 
 Orang-outang, Lamarck's theory of 
 
 change of to man, ii. 257 
 Orbigny, M. A. de, on Pampean mud, i. 
 
 131 
 Orbit of the earth, how far excentric, 
 
 and why, i. 269 
 Organic life, progressive development 
 
 of, i. 147 
 
 remains, controversy as to origin of, 
 i. 34 
 
 imbedding of, in subaqueous de- 
 posits, ii. 524 
 
 imbedded in volcanic formations, 
 
 ii. 509 
 
 world-changes in the, ii. 244 
 Organisms, eventual success of higher, 
 
 ii. 489 
 
 Oriental cosmogony, i. 6 
 ' Origin of Species,' by Darwin, effect of 
 
 its publication, ii. 281 
 Orkney Islands, waste of, i. 507 
 Otaheite. See Tahiti. 
 Ovid, sketch of Pythagorean doctrines, 
 
 i. 17 
 
 Owen, Professor, on British fossil mam- 
 malia and birds, i. 159 
 
 theory of progression, i. 155 
 
 Polar ichthyosaurus, i. 219 
 
 sub-classes of mammalia, i. 165 
 
 cited, i. 214, 219 
 
 on teeth of mammoth, i. 187 
 
 Parthenogenesis, ii. 291 
 
 Ichthyopterygia, ii. 478 
 
 rank of Dryopithecus, ii. 483 
 
 homologous structure of man 
 
 and ape, ii. 485 
 cerebral classification of verte- 
 
 brata, ii. 486 
 
 bones of turtles, ii. 573 
 
 extinction of the Dodo, ii. 457 
 
 geographical relationship of 
 
 fossil to living mammalia, ii. 334 
 
638 
 
 GENERAL INDEX. 
 
 PAG 
 
 PLA 
 
 "PACIFIC, coral islands of the, ii. 596 
 JL Palsearctic region, mammalia of 
 
 the, ii. 341 
 Palaeolithic, or older stone age, climate 
 
 of, i. 177, 193 
 
 period, possible date of, i. 296 
 
 man, barbarism of, ii. 479, 493 
 
 period, implements of the, in Hamp- 
 shire drift, ii. 559 
 
 age, probable climate of the, ii. 563 
 Palestine shaken by earthquakes, i. 596 
 Palissy on animal origin of fossils, i. 
 
 35 
 Pallas on Caspian Sea, i. 66 
 
 fossil bones of Siberia, i. 181-183 
 
 mountains of Siberia, i. 66 
 
 domesticity eliminating sterility, 
 
 ii. 312 
 
 Palmer, Mr., on shingle beaches, i. 531 
 Panama, former submergence of isthmus 
 
 of, i. 254 
 
 tides in bay of, i. 496 
 
 supposed effects of submergence of 
 isthmus of, ii. 446 
 
 proportion of fish and shells common 
 to both sides of isthmus of, ii. 370 
 
 Pangenesis, Darwin's theory of, ii. 291 
 Papandayang, truncation of cone of, ii. 
 
 145 
 
 Papyrus rolls in Pompeii, i. 650 
 Paradise, Burnet on seat of, i. 48 
 Parana K., animals drowned in the, ii. 
 
 538 
 
 Paris, Artesian well near, i. 390 
 Parish, Sir Woodbine, on Chilian earth- 
 quake, ii. 154 
 animals drowned in Parana 
 
 R, ii. 538 
 Paroxysmal energy of ancient causes 
 
 controverted, i. 145 
 Parry, Capt. Sir E., on Polar bears 
 
 drifting on ice, ii. 360 
 Peat-bed, submerged, containing E. 
 
 primigenius, i. 545 
 Peat in delta of Ganges, i. 478 
 
 abundant in cold damp climates, ii. 
 496 
 
 animal substances preserved in, ii. 
 501 
 
 fossil animals buried in, ii. 505 
 
 fossilised objects buried in, ii. 499, 
 505 
 
 growth and analysis of, ii. 496, 502 
 
 mosses, bursting of, ii. 504 
 extent of, ii. 497 
 
 recent origin of some, ii. 499 
 
 Penco, in Chili, elevation near, ii. 155 
 Pengelly, Mr., on waste of Devonshire 
 
 coast, i. 538 
 history of St. Michael's Mount, 
 
 i. 542 
 
 Pennant on migration of animals, i. 179 
 Penzance, loss of land near, i. 543 
 Percy, Dr., on measurement of heat, ii. 
 
 207 
 
 Perihelion, its effect on climate, i. 275 
 Permian fossils imply warm climate, i. 
 
 222 
 
 period, supposed ice-action in, i. 222 
 Perrey, M. Alexis, on earthquakes, ii, 
 
 82, 228 
 
 volcanic eruptions, i. 588 
 
 Peru, volcanos in, i. 581 
 earthquake of 1746, ii. 156 
 Peruvian tradition of a flood, i. 1 1 
 Petroleum springs, i. 413 
 PhascolotJierium BucJclandi, i. 160 
 Pheasants, two species of which breed 
 
 together, ii. 311 
 Phillippi, Dr. A., on gradual change of 
 
 species in Sicily, i. 312 
 
 fossil shells of Etna, ii. 6 
 
 Phillips, Professor, on waste of York- 
 shire coast, i. 510 
 heat increasing below earth's 
 
 surface, ii. 205 
 Phlegrsean Fields, volcanos of, i. 608, 
 
 616 
 
 Pietra Mala, inflammable gas of, i. 18 
 Pigeon, 150 races of domesticated, ii. 
 
 289 
 
 great changes made by man in the, 
 ii. 289 
 
 reversion of to Columba Livia when 
 crossed, ii. 290 
 
 all domestic races of interbreed, ii. 
 305 
 
 Pigs, powers of swimming of, ii. 356 
 Pikermi, near Athens, fossil mammalia 
 
 of, ii. 482 
 Pimpernels, sterility of crossed varieties 
 
 of, ii. 308 
 Pingel, Dr., on sinking of west coast of 
 
 Greenland, ii. 196 
 Pini on height and size of Monte Nuovo, 
 
 i. 607 
 
 Pitch-lake of Trinidad, i. 414 
 Plants, fossil, y their bearing on theory of 
 
 progression, i. 148 
 of Carboniferous period, i. 224 
 
 agency of man in dispersing, ii. 397 
 animals in distribution of, ii. 
 
 394 
 
 absence of boreal, on Madeiran 
 mountains, ii. 417 
 
 cosmopolite character of cryptoga- 
 mous, ii. 387 
 
 with winged seeds, ii. 388 
 
 dispersion of, ii. 386 
 
 geographical distribution of, ii. 381 
 
 of Atlantic islands compared to 
 British, ii. 421 
 
GENERAL INDEX. 
 
 639 
 
 PLA 
 
 PRO 
 
 Plants of Australia and Europe com- 
 pared, ii. 384 
 
 different parts of altered by man, ii. 
 298 
 
 effects of increase of one species in 
 exterminating others, ii. 447 
 
 freshwater, buried in marine de- 
 posits, ii, 565 
 
 fertilised by insects have coloured 
 corolla, ii. 309 
 
 hermaphrodite, often not self-ferti- 
 lised, ii. 309 
 
 Himalayan flowering, ii. 319 
 
 hybridisation of, ii. 306 
 
 imbedding of in subaqueous deposits, 
 ii. 525 
 
 mineralisation of, ii. 532 
 
 number of known species of, ii. 270 
 
 number of species known to ancients, 
 ii. 381 
 
 provinces of birds applicable to, ii. 
 385 
 
 stable and unstable genera of, ii. 282 
 
 fossil in tuffs of Etna, ii. 6 
 
 imbedding of marine, ii. 571 
 
 provinces of marine and dispersion 
 of, ii. 386, 391 
 
 relationship of Madeiran to Europe, 
 ii. 417 
 
 wild hybrid, ii. 324 
 
 ' Plastic virtue' of earth, theory of, i. 20, 
 40 
 
 Platyrrhine, or New-world monkeys, ii. 
 331 
 
 Playfair's illustrations of Hutton, i. 78, 
 83 
 
 Playfair on formation of Lake of Ge- 
 neva, i. 420 
 
 change of level of Baltic, ii. 183 
 Pliny on new islands in Mediterranean, 
 
 i. 25 
 
 the Elder, killed on Vesuvius, i. 603 
 
 the Younger, on Vesuvius, i. 603 
 
 combustible nature of our planet, ii. 
 234 
 
 Pliocene strata, climate of, i. 198 
 Plot on organic remains, i. 40 
 Pluche on the deluge, i. 50 
 Plutarch on doctrines of Anaximander, 
 
 i. 15 
 Plutonic rocks, cexture and origin of, 'i. 
 
 142 
 Po, River, frequently shifts its course, 
 
 i. 423 
 
 embankment of the, i. 423 
 delta of, i. 423 
 Poisson, M., on heat received by earth in 
 
 passing through space, i. 302 
 consolidation of the globe, ii. 
 
 207 
 Polar land, now abnormal, i. 247 
 
 Pollen of plants, prepotency of natural 
 
 over foreign, ii. 310 
 Pompeii, infusorial beds covering, i. 644 
 
 mass enveloping, i. 640 
 
 section of the mass enveloping, i. 
 642 
 
 objects preserved in, i. 645-647 
 
 skeletons buried in, i. 648 
 
 Pont Gibaud, calcareous springs near, i. 
 
 400 
 Ponzi, Professor, on fossil mammoths of 
 
 Monte Sacro, i. 186 
 Porites clavaria, ii. 582 
 Port Hudson Bluff, buried forest in, i. 
 
 462 
 
 Royal, Jamaica, subsidence of, ii. 160 
 
 buried houses of, ii. 553 
 
 Portland, fossil ammonites of, i. 42 
 
 Isle of, wasting away, i. 533 
 
 Porto Santo, Madeira, denudation of 
 
 rocks of, ii. 425 
 number of landshells peculiar to, 
 
 ii. 423 
 Pothocites Grantonii, monocotyledon in 
 
 the coal, i. 149 
 Pottery, absence of, in caves of Reindeer 
 
 period, ii. 559 
 
 in upraised marine strata, Sardinia, 
 ii. 563 
 
 Pratt, Archdeacon, on effect of polar ice- 
 cap, i. 291 
 
 Precession, four cycles of, how divided, 
 i. 274 
 
 climate of successive phases of, i. 280 
 
 of the Equinoxes, i. 274 
 
 - as testing thickness of earth's crust, 
 
 ii. 203, 240 
 Prejudices of man as an inhabitant of 
 
 land, i. 99 
 
 Prentice, Lieut., on coral reef of Mal- 
 dives, ii. 583 
 Prestwich, Mr., on Artesian wells, i. 
 
 389 
 
 on climate of drift, i. 192 
 Prevost, M. Constant, on rents formed 
 
 by upheaval, i. 613 
 
 Thylacotherium, i. 159 
 
 Graham Island, ii. 60 
 
 his division of geological 
 
 causes, ii. 495 
 
 on fossils in caves, ii. 520 
 
 Prichard, Dr., on absence of mammalia 
 
 in islands, ii. 411 
 
 Egyptian cosmogony, i. 12 
 
 Progression, theory of, bearing of fossil 
 
 animals on, i. 150 
 
 plants on, i. 148 
 
 mollusca on, i. 151 
 
 fish on, i. 153 
 
 reptiles on, i. 155 
 
 birds on, i. 157 
 
640 
 
 GENERAL INDEX. 
 
 PEO 
 
 EEI 
 
 Progression, theory of, bearing of fossil 
 
 mammalia on, i. 158 
 Progressive development of organic life, 
 
 i. 146-173 
 
 held by Lamarck, ii. 257 
 
 in man chiefly cerebral, ii. 485, 
 
 487 
 Protean or polymorphous genera, ii. 
 
 327 
 Provinces of animals coincident with 
 
 marked human races, ii. 473 
 
 Zoological. See Eegions. 
 Pumice, eggs of Mollusca transported 
 
 in, ii. 376 
 
 Pumiceous strata of White Island, ii. 68 
 Purbeck, peninsula of, wasting away, i. 
 
 533 
 
 oolitic mammalia of, i. 161 
 Puzzuoli, marine upraised deposit at, ii. 
 
 165 
 
 temple of Serapis near, ii. 165 
 
 section of marine strata near, ii. 167 
 Pythagoras, system of, i. 16 
 
 QUADRUMANA, fossil, 164 
 gradational extinct forms of, ii. 
 
 483 
 
 Quadrupeds. See Mammalia. 
 Quaggas, migrations of, ii. 358 
 Quatrefages on varieties of silkworms, 
 
 ii. 297 
 Queenstown, ravine of Niagara near, i. 
 
 359, 361 
 
 Quirini on diluvial theory, i. 39 
 Quito, volcanos of, i. 582 
 earthquakes of 1797, ii. 112, 159 
 
 "DABBITS, Feral, modified in Porto 
 
 It Santo, ii. 313 
 
 ' Races,' tidal currents so called, i. 572 
 
 antiquity of some artificially formed, 
 ii. 282 
 
 of man, their distribution, ii. 464 
 
 distribution of human, coincident 
 with zoological provinces, ii. 473 
 
 fertility when crossed of domestic, 
 ii. 305 
 
 tendency to herd apart of domestic, 
 ii. 311 
 
 Radiation impeded by snow, i. 284 
 Raffles, Sir S., on earthquakes in Java, 
 
 ii. 105 
 Rafts of the Mississippi, i. 444 
 
 floating, carrying animals, ii. 361 
 Rain, action of, i. 329 
 
 fall of, in England, Norway, and 
 India, i. 329, 330 
 
 basin of Ganges, i. 330 
 
 Eastern Bengal, i. 350 
 
 Rainfall, variations in average, i. 329 
 
 Rainless regions, i. 332 
 
 Rain-prints, recent, i. 333 
 
 Raised beaches, i. 290 
 
 Ramsay, Professor, on Miocene ice-^ 
 
 action, i. 206 
 foreign matter in Bath springs, 
 
 i. 398 
 ice-action in Permian times, 
 
 i. 222 
 
 of Devonian times, i. 230 
 
 Raspe on new islands, i. 19, 62 
 
 basalt, i. 71 
 
 Rat, introduced by man into America, 
 
 ii. 367 
 
 Rats, migrations of, ii. 357 
 Ravine excavated in Georgia, i. 344 
 Rawlinson, Colonel, on delta of Tigris, 
 
 i. 484 
 Ray, his physico-theological theory, &c., 
 
 i. 45 
 Reaumur on multiplication of insects, 
 
 ii. 439 
 Recapitulation of causes of earthquakes 
 
 and volcanos, ii. 240 
 Reculver cliff, action of sea on, ii. 523 
 
 church, views of in 1781 and 1834, i. 
 523, 524 
 
 Recupero on flood in Val del Bove, ii. 
 
 37, 39 
 Red marl, supposed universality of, i. 
 
 114 
 
 River, new lakes formed by, i. 454 
 drift wood in, i. 444 
 
 juncture of, with Mississippi, i. 
 
 457 
 
 Sea, level of, i. 496 
 
 Ehrenberg on corals of, ii. 583- 
 
 591 
 
 Indian, his unity of type throughout 
 America, ii. 473 
 
 Redman on changes of English coast, i. 
 
 528 
 
 Redmann, Dr., on snow-capped moun- 
 tain on the equator, i. 248 
 Reefs, formation of barrier, ii. 601 
 Refrigeration, Leibnitz's theory of, i. 40 
 Regelation, theory of, applied to glaciers, 
 
 i. 373 
 Regions, botanical, ii. 382 
 
 of mammalia and birds, ii. 335 
 
 neotropical of mammalia, ii. 335 
 
 nearctic of mammalia, ii. 340 
 
 Palsearctic of mammalia, ii. 341 
 
 Ethiopian of mammalia, ii. 343 
 
 Indian of mammalia, ii. 346 
 
 Australian of mammalia, ii. 347 
 
 ' Reign of Law,' by Duke of Argyll, criti- 
 cisms on Darwin in the, ii. 489 
 
 Reindeer period, possible date of, i. 
 295 
 
GENERAL INDEX, 
 
 641 
 
 EEI 
 
 RUN 
 
 Reindeer, increase of, imported into Ice- 
 land, ii. 450 
 
 migrations of the, ii. 357 
 Reinhardt on migration of Greenland 
 
 whales, i. 286 
 Rennell on oceanic currents, i. 495, 
 
 499 
 
 Ganges, i. 471, 473 
 
 the recipient of the gulf-water, i. 
 
 244 
 
 velocity of Plate River, i. 497 
 
 Rennie on peat-mosses, ii. 498 
 Reptile life ; how far affected by absence 
 
 of mammalia, i. 220 
 Reptiles, absence of, in temperate parts 
 
 of the southern hemisphere, i. 219 
 
 abundance of, implying warm cli- 
 mate, i. 219 
 
 as bearing on progression, i. 1 55 
 
 of the Chalk, i. 214 
 Coal, i. 229 
 
 Miocene strata, i. 200 
 
 migration of, ii. 365 
 
 imbedding of, ii. 534 
 marine, ii. 573 
 
 Rescobie, swelling up of a mound in 
 
 Loch of, i. 453 
 Reversion in cross-breeds to the parent 
 
 stock, ii. 290 
 
 to lost characters evoked by crossing 
 distinct varieties, ii. 290 
 
 Reynauld on climate aifected by excen- 
 
 tricity, i. 270 
 Rhine, inroad of sea at mouths of the, i. 
 
 548 
 
 changes in the arms of the, i. 549 
 
 its delta, i. 550 
 
 Rhinoceros, fossil, of Siberia, i. 183 
 
 gradational extinct forms of, ii. 483 
 Rhone, deposits of, at confluence of with 
 
 Arve, i. 489 
 
 delta of, in Lake of Geneva, i. 417 
 
 marine delta of, i. 427 
 
 a cannon in calcareous rock in delta 
 of, ii. 549 
 
 Richards, Captain, cited, i. 461 
 Richardson, Sir J., on animals buried 
 
 in drift snow, i. 189 
 
 isothermal lines, i. 236 
 
 distribution of animals, ii. 
 
 340 
 
 distribution of fish, ii. 369 
 
 drift timber in Slave Lake, 
 ii. 526 
 
 migrations of musk-ox, ii. 361 
 
 sheep of Rocky Mountains, ii. 
 304 
 
 Riddell on sediment of Mississippi, i. 
 
 458 
 Rink on fossil trees in arctic latitudes, 
 
 i. 203 
 
 VOL. II. T T 
 
 Rink on evaporation of snow in Green- 
 land, i. 287 
 ice-streams in Baffin's Bay, i. 288 
 
 Ritter, H., on doctrines of Anaximan- 
 der, i. 16 
 
 River-ice, carrying power of, i. 363 
 
 and currents, comparative transport- 
 ing power of, i. 570 
 
 courses, deranged by Calabrian earth- 
 quake, ii. 129 
 
 Rivers, action of, i. 343 
 
 colour of, caused by sediment, i. 
 309 
 
 floods in Scotland, i. 349 
 
 sinuosities of, i. 346 
 
 velocity of two united, i. 348 
 
 agency of in dispersion of plants, i. 
 389 
 
 engulphed, of the Morea, ii. 517 
 Roberts, Mr. E., on New Zealand earth- 
 quake, ii. 85, 88 
 
 Robertson, Capt., on mud volcanos, ii. 
 
 77 
 Roches moutonn^es, i. 375 
 
 near earth-pillars in the Ritten, 
 
 i. 340 
 Rockall Bank, fossil shells at great 
 
 depths at, ii. 576 
 Rocks, action of frost on, i. 367, 385 
 
 older, why most solid and disturbed, 
 i. 119 
 
 overturned by lightning, i. 504 
 
 transportation of, by glaciers, i. 374 
 
 difference of texture in older and 
 newer, i. 40 
 
 Romney Marsh, gained from sea, i. 528 
 Roses, number of species in Britain, ii. 
 
 326 
 
 Ross, Captain Sir J., on floating ice- 
 bergs, i. 382 
 
 high antarctic land, a 
 source of cold, i. 242 
 
 grounded icebergs in 
 
 Baffin's Bay, i. 245 
 
 thickness of antarctic 
 
 ice, i. 287 
 
 erratic blocks in Victoria 
 Land, i. 287 
 
 Rossberg, landslip of the, ii. 513 
 Rotation of the earth, currents caused 
 
 by, i. 500 
 Rother, R., vessel found in bed of, ii. 
 
 547 
 Roulin, M., on Mexican hunting-dogs, 
 
 ii. 294 
 Round Tower of Terranuova, fault in, 
 
 ii. 123 
 Rudimentary organs, their bearing on 
 
 transmutation, ii. 273 
 Runn of Kutch, salt deposit in, i. 228 
 described, ii. 102 
 
642 
 
 OENEBAL INDEX. 
 
 RUT 
 
 SEA 
 
 Kutimeyer on monkey in Middle Eocene, 
 
 i. 164 
 Habkeren blocks, i. 210 
 
 SABINA and Graham's Island erup- 
 tions, ii. 408 
 
 Sabine, General, on marine currents, i. 
 497 
 
 Artesian well, i. 390 
 
 casks carried by currents, i. 
 499 
 
 solar magnetic period, i. 303 
 
 Sabrina, new volcanic island of, ii. 58 
 Ssemann, Louis, on chemical affinity, ii. 
 
 234 
 Sahara, former submergence of, dividing 
 
 N. African and Ethiopian faunas, ii. 
 
 340, 344 
 St. Cassian beds, marine fauna of, i. 
 
 221 
 
 St. Helena, tides at, i. 494 
 changes wrought by man among 
 
 species in, ii. 453 
 
 multiplication of goats in, ii. 412 
 
 St. Lawrence River, view of rocks drifted 
 
 by ice in the, i. 364 
 St. Michael's Mount, three views of, i. 
 
 540 
 
 unchanged during many cen- 
 turies, i. 539 
 St. Andrew's, buried gun-barrel near, ii. 
 
 550 
 St. Domingo, earthquake of, 1770, ii. 
 
 146 
 hot springs bursting forth during 
 
 earthquake, ii. 146 
 Salisbury, fossil egg of wild goose near, 
 
 ii. 563 
 Salt-springs, i. 410 
 
 water, access of to volcanic foci, ii. 
 223 
 
 Salto della Giumenta, Etna, lava cas- 
 cades in, ii. 33 
 
 Salvages, fauna and flora of the, ii. 410 
 Samoa, submarine volcanic eruption 
 
 near, ii. 409 
 
 Samothracian deluge, i. 593 
 Sand-bars on coast of Adriatic, i. 424 
 Sand-dunes, i. 516 
 
 cones thrown up during earthquakes, 
 ii. 128 
 
 Sandfloods overwhelming towns, ii. 508 
 Sands, imbedding of human remains, 
 
 &c., in, ii. 506 
 Sandwich Islands, volcanos of, i. 590; 
 
 ii. 214 
 
 San Filippo, baths of, i. 402 
 Santa Maria, isle of, upraised, ii. 93 
 Santorin ; geological formation of, ii. 72 
 
 absence of dikes in, ii. 73 
 
 Santorin, date of old volcanic formations, 
 ii. 74 
 
 shells in pumiceous ash of, ii. 68 
 
 eruption of 1866, ii. 69 
 
 crater-like form of islands, ii. 71 
 
 volcanic eruptions in, ii. 65 
 
 map and sections of, ii. 66 
 
 San Vignone, travertin formed by springs 
 
 of, i. 401 
 Sardinia, pottery in upraised marine 
 
 strata of, ii. 563 
 Sargassum banks, question of origin of, 
 
 ii. 392 
 Saunders, Mr., on distribution of land 
 
 and sea, i. 257-262 
 Saussure, de, on Lake of Geneva, i. 418 
 
 Alps and Jura, i. 67 
 
 Savannahs, animals drowned while 
 
 grazing over, ii. 538 
 Scacchi, Professor A., on formation of 
 
 Monte Nuovo, i. 613 
 cited, i. 615, 628 
 
 S., on rate of subsidence of Temple 
 of Serapis, ii. 175 
 
 Scandinavia, average rise of land in, 
 i. 137 
 
 . See Sweden. 
 
 Scania in Sweden, subsidence of, ii. 191 
 
 Scheuchzer on fossil fish, i. 50 
 
 Schmerling, Dr., on fossils in caves, ii. 
 520 
 
 Schmidt, M. Julius, on Santorin vol- 
 canic eruption, ii. 69 
 
 Scilla on Calabrian fossils, i. 37 
 
 fall of sea-cliffs near rock of, ii. 134 
 Sclater, Dr., on geographical regions of 
 
 birds, ii. 335 
 Scoresby on influence of Gulf- stream 
 
 in Spitzbergen, i. 245 
 
 boat sunk by a whale, ii. 525 
 
 Scoriae, ropy, of Vesuvius, i. 625 
 Scotland, action of the sea on coast of, i. 
 
 508 
 
 river-floods in, i. 349 
 
 animals washed away in floods of, ii. 
 537 
 
 Scrope, Mr., on basalts of Vesuvius, i. 
 
 633 
 
 Vesuvian eruption, i. 621 
 
 formation of volcanic cones, i. 
 
 629 
 
 drawing of Ischia by, i. 601 
 
 cited, i. 605 
 
 on eruptions of Etna, ii. 29 
 
 convexity of Malpais plain, Jo- 
 
 rullo, ii. 54 
 
 Scudder,Mr., on Devonian insects, i. 157 
 Sea, its influences on climate, i. 248 
 
 action of, on the British coast, i. 502 
 apparent change of level caused by 
 rise of land, i. 24 ii. 179 
 
GENERAL INDEX. 
 
 G43 
 
 SEA 
 
 Sea, depth of, compared to height of land, 
 i. 265 
 
 extent of open, at north pole, i. 
 285 
 
 encroachments of, on coasts, i. 502, 
 548, 552, 556, 559 
 
 beaches, progressive movement of, 
 i. 531 
 
 whether caused by attraction of 
 
 ice-cap, i. 290 
 
 preservation of human remains in 
 the, ii. 542 
 
 proofs of permanence of level of, ii. 
 181 
 
 retreat of during Lisbon earthquake, 
 ii. 150 
 
 weed, distribution of species, ii. 391 
 Sedgwick, Professor, on Devonian strata, 
 
 i. 32*0 
 on organic remains in fissures, 
 
 ii. 522 
 Sediment of the Mississippi, i. 458 
 
 rate of subsidence of some kinds of, 
 i. 573 
 
 area over which it may be tran- 
 sported by currents, i. 574 
 
 laws governing deposition of, i. 573 
 
 brought down by Granges, i. 481 
 
 transfer of by rivers and currents, ii. 
 238 
 
 Sedimentary deposition, causes which 
 occasion a shifting of the areas of, i. 
 307 
 
 uniformity of change in, i. 307 
 
 Seeds carried on feet and in stomachs of 
 birds, ii. 396, 421 
 
 collected by savages for food, ii. 286 
 
 conveyed to islands by icebergs, ii. 
 419 
 
 Selection, natural, compared to artificial, 
 ii. 316 
 
 by man ' unconscious ' and ' methodi- 
 cal,' ii. 288 
 
 Selkirk, Lord, on rise of land in Sweden, 
 
 ii. 187 
 
 Sequence of formations explained, i. 324 
 Serapis, temple of Jupiter, at its period 
 
 of greatest depression, ii. 172 
 elevation and subsidence of, 
 
 ii. 171 
 
 ground plan of environs of, 
 
 ii. 165 
 
 history of, ii. 168 
 
 described, ii. 170 
 
 date of modern subsidence, ii. 
 
 174 
 Serra del Solfizio, on Etna, dip and curve 
 
 of lavas of, ii. 15 
 
 Sertularia, producing medusae, ii. 327 
 Seven Sleepers, legend of, i. 97 
 Severn, tides in estuary of, 494 
 
 SIL 
 
 Shakespeare's Cliff, waste of, i. 526 
 Sharpe, Mr. S., on deposition of Nile 
 
 mud, i. 436 
 
 on earthquake at Lisbon, ii. 148 
 
 Sheep, Norfolk, herding apart, ii. 311 
 Shell-marl, animal remains imbedded in, 
 
 ii. 536, 565, 571 
 
 lakes of, ii. 536, 565, 571 
 
 Shells of Carboniferous period, i. 228 
 the drift as proofs of climate, i. 
 
 192 
 
 marine, in New Orleans Artesian 
 well, i. 459 
 
 supposed fossil, of Somma, i. 637 
 
 upraised, of the Baltic, i. 314 
 
 fossil, of delta of the Amazons, i. 
 467 
 
 importance of, i. 312 
 
 number of recent, in different Tertiary 
 periods, i. 312 
 
 burrowing, ii. 575 
 
 fossil, at great depths, ii. 575 
 
 in upraised marine strata in Swe- 
 den, ii. 193 
 
 wide range of some, ii. 373. See 
 Mollusks. 
 
 Sheppey, Isle of, waste of coasts in, i. 
 
 522 
 Shetland Isles, action of the sea on, i. 
 
 502 
 rock masses, drifted by the sea 
 
 in, i. 503 
 effects of lightning on rocks in, 
 
 i. 503 
 shelly formation now in progress 
 
 near, ii. 576 
 
 Shingle beaches, i. 531-534 
 Ships, fossil, ii. 546-548 
 
 number of wrecked, ii. 542-545 
 Shoals and submarine valleys in Ger- 
 man Ocean, i. 568 
 
 Siberia, map of, i. 182 
 
 lowland of, i. 181 
 
 extension of lowland of, i. 188 
 Siberian mammoths, i. 182-191 
 
 rhinoceros entire in frozen soil of 
 Siberia, i. 183 
 
 Sichet, Dr., on deafness in cats, ii. 314 
 Sicily, earthquakes in, i. 594; ii. 113, 
 159, 519 
 
 recent testacea in limestone of, i. 
 313 
 
 mud volcanos of, ii. 76 
 Sidell, Colonel, on mud-lumps of Mis- 
 sissippi, i. 451, 452 
 Silex deposited by springs, i. 408 
 Siliceous springs of Azores, i. 408 
 Silkworms, improved by man's selec- 
 tion, ii. 296 
 
 Silliman, Prof., on buried schooner in 
 Xova Scotia, ii. 548 
 
 T T 2 
 
644 
 
 GENEKAL INDEX. 
 
 SIL 
 
 SPI 
 
 Silting up of estuaries, i. 557 
 Silurian period, climate of, i. 231 
 Silver Pits, excavation of, i. 569 
 Simeto, Eiver, excavation of lava by, i. 
 
 357 
 
 Sindree, Fort of, submerged by earth- 
 quake in Cutch, ii. 102 
 Sink-holes, described, ii. 109 
 Siwalik Hills, fossils of the, i. 201 
 Six-fingered variety of man, ii. 476 
 Skaptar Jokul, eruption of, ii. 49 
 Skeletons, human, in rock of Guada- 
 
 loupe, ii. 544 
 
 Sleswick, waste of coast in, i. 557 
 Sligo, bursting of a peat-moss in, ii. 504 
 Sloane, Sir H., on dispersion of plants, 
 
 ii. 390 
 Smith, William, his tabular view of 
 
 British strata, i. 84 
 
 Smith, Mr., of Jordanhill, on rate of 
 subsidence of Temple of Serapis, ii. 
 175 
 
 Smyrna, volcanic country round, i. 592 
 Smyth, Admiral, on depth and cur- 
 rents of Mediterranean, i. 561-564 
 
 temperature of Mediterranean, 
 
 i. 65 
 
 depth of Mediterranean, i. 429 
 
 shells at great depth at Gi- 
 braltar, ii. 575 
 
 floating islands, ii. 363 
 
 height of Etna, ii. 1 
 
 insects blown by wind, ii. 380 
 
 level of Mediterranean, ii. 168 
 
 number of wrecked vessels, ii. 
 
 546 
 
 Snags of the Mississippi River, i. 446 
 Snakes of Japan of Indian origin, ii. 
 
 343 
 Snow, evaporation of, in dry air, i. 286 
 
 impeding radiation of heat, i. 284 
 
 line at equator, i. 248 
 
 limit of perpetual, i. 367 
 Sodertelje, in Sweden, buried fishing hut 
 
 near, ii. 187 
 
 Solar tide, comparatively small, i. 110 
 Solar magnetic periods, i. 303 
 
 System, supposed secular loss of heat 
 in, ii. 213 
 
 Soldani on microscopic shells of the Me- 
 diterranean, i. 65 
 
 Paris basin, i. 65 
 
 Solent, channel when excavated, ii. 563 
 Solfatara, Lake of the, i. 404 
 
 extinct volcano of, i. 602 
 
 Solway moss, description of the, ii. 503 
 Somersetshire, submarine forest on coast 
 
 of, i. 545 
 Somma, Monte, supposed recent fossil 
 
 shells of, i. 637 
 
 slope of escarpment of, i. 631 
 
 Somma, formed like Vesuvius, i. 637 
 Sorbonne, College of the, i. 58 
 South Carolina, earthquake in, ii. 106 
 
 Georgia, climate of, i. 240 
 Southern hemisphere, cold of, due to 
 
 geographical conditions, i. 277 
 Space, temperature of, i. 278 
 Spada on origin of marine fossils, i. 51 
 Species, theories on eras of creation of, 
 
 i. 22 
 
 gradual change of, in successive stra- 
 ta, i. 311 
 
 rate of change in, available in geolo- 
 logical chronology, i. 300 
 
 aquatic, buried in subaqueous strata, 
 ii. 565 
 
 Brocchi on the dying out of, ii. 268 
 
 causes why one survives and another 
 dies out, ii. 433 
 
 how an equilibrium is preserved be- 
 tween, ii. 435, 442 
 
 definition of the term, ii. 245 
 
 have they a real existence, ii. 245 
 
 dying out and coming in of, ii. 267, 
 269, 272 
 
 extension of one alters range of 
 other, ii. 446-449 
 
 extirpation of, by man, ii. 451 
 
 evolution of, does not exclude crea- 
 tive power, ii. 492 
 
 extinction of, ii. 433-463 
 
 how affected by changes in physical 
 geography, ii. 443 
 
 Lamarck's definition of term, ii. 246 
 theory of transmutation of, ii. 246 
 
 Linnseus' definition of, ii. 267 
 
 loss of one easier to prove than 
 coming in of another, ii. 463 
 
 new cannot be produced by man, ii. 
 285 
 
 power of exterminating, no preroga- 
 tive of man, ii. 460 
 
 their possible rapid increase, ii. 317 
 
 reciprocal effect of aquatic and terres- 
 trial, ii. 442 
 
 two rational, could not coexist on 
 the globe, ii. 481 
 
 ' Vestiges of Creation ' on, ii. 27-4 
 
 Mr. Wallace on nature of, ii. 276, 
 280 
 
 whether indefinitely variable, ii. 300 
 Specific centres, doctrine of, ii. 336 
 Spencer, Herbert, on 'survival of the 
 
 fittest,' ii. 318 
 
 principle of inheritance, ii. 291 
 
 Spermophilus, skeletons of, in attitude 
 
 of hibernation, ii. 563 
 Spix and Marti us on extirpation of 
 
 species by man, ii. 454 
 
 on animals carried on floating is- 
 lands, ii. 362 
 
GENERAL INDEX. 
 
 645 
 
 SPO 
 
 SUT 
 
 Spontaneous generation, theory of, i. 34 
 believed by author of ' Vestiges,' 
 ii. 276 
 
 Spratt, Captain, on deptli and tempera- 
 ture of Mediterranean, i. 562-504 
 
 Springbok, migrations of the, ii. 358 
 
 Springs, ferruginous, i. 410 
 
 brine, i. 410 
 
 carbonated, of Auvergne, i. 411 
 
 siliceous, of Azores, i. 408 
 
 origin of, i. 387 
 
 of petroleum, i. 413 
 
 temperature of, raised by earth- 
 quakes, i. 395 
 
 hot, abundant in volcanic regions, 
 i. 394 
 
 calcareous, i. 399 
 
 sulphureous and gypseous, i. 408 
 
 thermal, of Bath, i. 398 
 
 affected by earthquakes, ii. 128, 146 
 Squirrels, migrations of, ii. 357 
 Stabise, buried city of, i. 651 
 Stalagmite, alternating with alluvium 
 
 in caves, ii. 520 
 
 Stalagmitic limestone of Cuba, ii. 522 
 Stanley, Hon. W., on head of mammoth 
 
 in sunk peat-bed, i. 545 
 Stars, variable splendour of, i. 303 
 
 heat of the, compared to that of the 
 sun, i. 279 
 
 Stations of plants described, ii. 383 
 
 conditions which affect the, 
 
 ii. 443 
 
 Staveren, formation of Straits of, i. 553 
 Steam, agency of in volcanic eruptions, 
 
 ii. 214, 221, 242 
 
 Steno, advanced theories of, i. 36 
 Stephenson on eruption in Iceland, ii. 49 
 Stereognathus, jaw of, from Stonesfield, 
 
 i. 160 
 Sterility, tendency of domesticity to 
 
 eliminate, ii. 312 
 Stevens, Mr. Alfred, on Bournemouth 
 
 flint implements, ii. 562 
 Stevenson, Mr., on waste of cliffs, i. 546 
 Stockholm, rise of laud near, ii. 186 
 Stone, E. T., on former excentricities of 
 
 the earth's orbit, i. 292 
 Stone Age, climate of, i. 176, 193 ; ii. 563 
 Stonesfield, fossils of, i. 161 
 Storm, magnetic, of Sept. 1859, ii. 231 
 Storms, effects of, on beach, i. 535 
 Strabo cited, i. 427, 430 
 
 theory of, i. 23 
 
 on mud raising the bed of Euxine, i. 
 23 
 
 Strachey, Colonel, on delta of Ganges, 
 
 i. 482 
 Strata contorted by ice, i. 383 
 
 consolidation of, i. 140 
 
 table of fossiliferous, i. 139 
 
 Strata, examples of curved and hori- 
 zontal, i. 315, 316 
 
 ancient, submerged, and therefore 
 inaccessible, i. 156 
 
 Stratifications in deltas, causes of, i. 
 488 
 
 of debris deposited by currents, i. 
 489 
 
 Strickland, Mr., on extinction of the 
 Dodo, ii. 457 
 
 Stromboli, state of, during Calabrian 
 earthquake, ii. 134 
 
 Stufas, jets of steam in volcanic regions, 
 i. 394 
 
 Styx rock off Porto Santo, ii. 405, 426 
 
 Subapennine strata, climate of, i. 199 
 
 Subaqueous deposits, imbedding of fos- 
 sils in, ii. 524 
 
 Submarine forest on Hampshire coast, 
 ii. 529 
 
 volcanos, ii. 58, 63 
 Submergence, proofs of, in Secondary 
 
 and Primary rocks, i. 255 
 Subsidence, great areas of, i. 131 
 
 of land, ii. 165, 234, 552 
 Subterranean changes unseen by us, i. 
 
 99 
 
 movements, gradual development of, 
 i. 119 
 
 uniformity of, i. 315 
 Suffolk cliffs undermined, i. 519 
 Sulphureous springs, i. 408 
 Sulphuric acid, lake of, in Java, i. 589 
 Sumatra, linear arrangements of vol- 
 canos in, i. 590 
 
 animals drowned in river-floods in, 
 ii. 539 
 
 Sumbawa, great eruption in island of, 
 ii. 104 
 
 subsidence in, ii. 553 
 
 Summer's heat in perihelion counter- 
 acted by melting of snow, i. 271 * 
 
 cold in aphelion of extreme excentri- 
 city, i. 281 
 
 Sun, spots in the, ii. 230 
 
 Sunda, Isles of, volcanic region of, i. 
 
 585 
 Sunderbunds, low part of delta of 
 
 Ganges, i. 471 
 ' Sunk country ' of New Madrid, in 
 
 valley of Mississippi, i. 456; ii. 108 
 Superga, Miocene erratic blocks of, i. 
 
 206 
 Superior, Lake, deltas of, i. 421 
 
 fossil cypris and chara in, ii. 568 
 Surturbrand of Iceland, i. 202 
 
 ' Survival of the fittest,' ii. 318 
 
 will not account for pro- 
 gress of structure, ii. 491 
 Sussex, waste of coast of, i. 530 
 Sutlej, River, fossils near, i. 1 ^ 
 
G4G 
 
 GENERAL INDEX. 
 
 SWA 
 
 Swanage Bay excavated by sea, i. 531 
 ' Swatch' in the Bay of Bengal, i. 475 
 Sweden, rise of land in, i. 314 ; ii. 180- 
 196 
 
 map of, ii. 184 
 
 sinking of land in south of, ii. 190 
 Swinburn, Capt., on Graham Island, ii. 
 
 60, 62 
 
 Switzerland, towns destroyed by land- 
 slips in, ii. 513 
 
 Sykes, Colonel, on rainfall in India, i. 
 330 
 
 Syria, earthquakes in, i. 594 ; ii. 89 
 
 TABLE of fossiliferous strata, i. 139 
 varying excentricities of 
 
 earth's orbit, i. 293 
 
 Tahiti, coral reef of, ii. 592 
 
 Talus of Monte Nuovo, i. 615 
 
 Tamed animals often will not breed, ii. 
 313 
 
 Targioni on geology of Tuscany, i. 59 
 
 formation of limestone in Tus- 
 cany, ii. 610 
 
 Taxodium Distichum, ii. 506 
 
 Tay, estuary of, encroachment of sea in, 
 i. 508 
 
 Taylor on waste of Norfolk coast, i. 513 
 
 Revd. R., on New Zealand earth- 
 quake, ii. 82 
 
 Mr. R. C., on stalagmitic limestone 
 of Cuba, ii. 522 
 
 Teatro Grande, on Etna, ancient lava 
 
 current of, ii. 13 
 Temperature, formula for computing, i. 
 
 294 
 
 how far shown by extinct orders and 
 genera, i. 215 
 
 lowered by fog and melting of snow, 
 i. 271 
 
 "^effects of currents in equalising, i. 
 243 
 
 of Glacial period, i. 288 
 space, i. 278 
 
 supposed variations in, i. 301 
 
 . See Climate and Heat. 
 
 Temples buried in Cashmere, ii. 553 
 Terraces of Lake Superior, i. 421 
 Terranuova, subsidence near, ii. 122 
 Terrestrial changes, the system of, i. 325 
 
 and solar heat, supposed diminution 
 of, ii. 213, 241 
 
 Tertiary formations, geographical 
 
 changes implied by, i. 251 
 
 fossils of the newest, i. 311 
 
 fossil mammals of successive, i. 
 
 160 
 
 deposits, climate of, chiefly warmer 
 than at present, i. 199-203 
 
 Testa on Monte Bolca fish, i. 65 
 
 TllA 
 
 Testacea. See Mollusks and Shells. 
 
 burrowing, ii. 575 
 
 Texture, transition, of rocks, i. 141 
 Thames, valley of, Tertiary strata in, i. 
 192 
 
 buried vessels in alluvial plain of, 
 ii. 547 
 
 Thanot, Isle of, loss of land in, i. 525 
 Theophrastus, opinions of, i. 19, 20 
 Thera in Santorin, eruption and earth- 
 quakes of, 1650, ii. 67 
 Thermal springs frequent in volcanic re- 
 gions, i. 394 
 Thomson, Dr., on buried temples of 
 
 Cashmere, ii. 553 
 Thury, M. H. de, on Artesian wells, i. 
 
 390, 393 
 
 Thylacotherium Prevostii, figured, i. 159 
 Tibet, yak or wild ox of, in ice, i. 190 
 Tidal currents, depositing power of, i. 565 
 Tides, difference in the rise of the, i. 493 
 
 height to which they rise, i. 493 
 
 their destroying and transporting 
 power, i. 565 
 
 absence of internal, a proof against 
 central fluidity, ii. 208, 241 
 
 Tierra del Fuego, temperate climate of, 
 i. 241 
 
 Tigris and Euphrates, their union a mo- 
 dern event, i. 484 
 
 delta of the, i. 484 
 
 Time, prepossessions against length of 
 
 past, i. 91 
 Tivoli, flood of, i. 354 
 
 travertin of, i. 405 
 
 Torell, Mr., on date of marine upraised 
 
 strata in Sweden, ii. 193 
 Torquay, submerged forest of, i. 544 
 Torre del Greco overwhelmed by lava, 
 
 i. 65 
 Torrents, action of, in widening valleys, 
 
 i. 344, 346 
 Totten, Col., on expansion of stone by 
 
 heat, ii. 235 
 Towns overwhelmed by sandfloods, ii. 
 
 508 
 Toynbee, Capt. H., on moths flying far 
 
 from land, ii. 380 
 Trade winds, i. 497 
 Traditions of deluges, i. 593 ; ii. 154 
 Transition texture, i. 141 
 Transitional forms between species, ii. 
 
 339 
 Transmutation, objections urged against 
 
 theory of, ii. 261 
 
 Trap rocks of many different ages, i. 117 
 Travers, Mr. Locke, on rapid spread of 
 
 European plants in New Zealand, ii. 
 
 453 
 
 Travertin of the Elsa, i. 400 
 San Vignone, i. 400 
 
GENERAL INDEX. 
 
 (117 
 
 TEA 
 
 VOL 
 
 Travertin of San Filippo, i. 402 
 
 formed by calcareous springs, i. 401 
 
 of Tivoli, section of, i. 406 
 
 spheroidal structure of, i. 403 
 Tree ferns, distribution of, i. 224 
 Trias, fossil mammalia of, i. 161 
 Trifoglietto, ancient axis of Etna, ii. 11 
 Trinidad, pitch lake of, i. 414 
 Tristram, Mr., on volcanic deposits of 
 
 Eed Sea, i. 591 
 
 Truncation of volcanic cones, ii. 20, 145 
 Tufa. See Travertin. 
 Turtles, eggs of fossil, ii. 573 
 Tuscany, geology of, i. 59 
 
 formation of limestone of, ii. 610 
 Tyndal on motion of glaciers, i. 373 
 Tyrol, earth-pillars of, ii. 335 
 
 UDDEVALLA, change of level at, 
 since Glacial period, ii. 192 
 
 Ullah Bund, elevation of the, ii. 100 
 
 Ulloa on spread of wild ass in S. 
 America, ii. 459 
 
 Unconformable strata, inferences de- 
 rived from, i. 316 
 
 Uniformity of geological changes, i. 305- 
 309 
 
 Universal deposits, theory of, i. 112 
 
 ocean, theory of, i. 40, 51 
 Upheaval, proofs of slow, i. 131 
 
 signs of, in Atlantic islands, ii. 404 
 Upsala, upraised brackish water de- 
 posits near, ii. 194 
 
 YAL DEL BOVE, on Etna, changes 
 in, by modern eruptions, ii. 25-33 
 
 dikes in, ii. 16 
 
 flood in 1755, ii. 37 
 
 horizontal beds of, ii. 13 
 
 origin of, ii. 18 
 
 views and description of the, 
 ii. 78 
 
 Valleys, excavation of, in Central France, 
 i. 356 
 
 newly formed, i. 344 
 
 on Etna, ii. 8 
 
 excavation of, assisted by earth- 
 quakes, ii. 133 
 
 excavated since Palaeolithic man 
 lived, ii. 562 
 
 Vallisneri on natural causes of change, 
 i. 54 
 
 on origin of springs, i. 50 
 Valparaiso, coast raised at, ii. 94, 95 
 Variation accumulated by man in any 
 
 required direction, ii. 297 
 
 Are there definite limits to? ii. 300 
 
 of a species, number of causes pro- 
 ducing, ii. 318 
 
 Variation of races under domestication, 
 ii. 284 
 
 our ignorance of the laws producing, 
 ii. 490 
 
 Varieties, benefited by slight crossing, 
 ii. 320, 322 
 
 often merged into common stock, ii. 
 320 
 
 Vedas, sacred hymns of, i. 6 
 
 Venetz on recession of glaciers before 
 
 the tenth century, i. 278 
 Verneuil, M. de, cited, i. 251 
 
 on rocksalt of Cardona, i. 114 
 Vessels, wrecked. See Ships. 
 Vesta, temple of, i. 355 
 ' Vestiges of Creation ' on nature of 
 
 species, ii. 274 
 Vesuvian minerals, i. 632 
 Vesuvius, ancient history of, i. 602 
 
 renewal of eruptions of, i. 603 
 
 dikes of, i. 627 
 
 history of, after 1138, i. 606 
 
 modern eruptions of, i. 618 
 
 scoriae, ropy, i. 625 
 
 structure of cone of, i. 620 
 
 and Somma, ideal section of, i. 631 
 
 fossil leaves in tuffs of, i. 636 ; ii. 509 
 
 valleys on north side of, i. 634 
 Vidal, Capt., on shells at great depths 
 
 in the sea, ii. 576 
 Virginia, animals drowned in river floods 
 
 in, ii. 539 
 Virlet, M., on agglomerate of Santorin, 
 
 ii. 72 
 
 on Samothracian deluge, i. 593 
 corrosion of rocks by gases, ii. 
 
 515 
 human remains in breccia of 
 
 the Morea, ii. 517 
 Visp, earthquake at, in 1855, i. 311 
 Vistula, Eiver, its course diverted by 
 
 packed ice, i. 364 
 
 Vivarais, counter-current of lava in, ii. 51 
 Volcanic action defined, i. 577 
 
 district of Naples, i. 598 
 
 mud or ' moya' of Andes, i. 583 
 
 region from Asia to Azores, i. 591 
 
 regions, geographical boundaries of, 
 i. 579-597 
 
 vents, linear arrangement of, i. 577 
 
 accumulations, height of, in Madeira 
 and G-rand Canary, ii. 405 
 
 eruptions, hydrogen present in, ii. 
 224 
 
 foci, access of air and fresh water to, 
 ii. 225 
 
 eruption may possibly disperse land- 
 shells, ii. 430 
 
 eruptions, agency of steam in, ii. 214 
 
 dikes. See Dikes. 
 
 foci, access of salt water to, ii. 223 
 
648 
 
 GENERAL INDEX. 
 
 VOL 
 
 WHI 
 
 Volcanicformations, fossils imbedded in, 
 ii. 509 
 
 heat, magnetism and electricity 
 sources of, ii. 230 
 
 phenomena most consistent with par- 
 tial fluidity of earth's crust, ii. 209 
 
 submarine eruptions in 1 800, ii. 408 
 Volcanos, a cause of hot springs, i. 
 
 396 
 
 and atolls, map of active, i. 586 
 
 how to distinguish active from ex- 
 tinct, i. 597 
 
 of Phlegrsean Fields, i. 616 
 Sandwich Islands, i. 590 
 
 safety valves, according to Strabo, 
 i. 25 
 
 and earthquakes, common origin of, 
 ii. 198, 240 
 
 recapitulation of causes of, ii. 
 240 
 
 limited areas of, at any one period, 
 ii. 210 
 
 mud cones, ii. 75 
 
 submarine, ii. 58 
 
 why frequent at junction of sea and 
 land, ii. 229 
 
 Voltaire's attacks on Geology, i. 79 
 Von Baer, on ice-drifted rocks, i. 385 
 Von Buch cited, i. 225 
 on felspathic volcanic rocks, i. 
 
 580 
 formation of Monte Nuovo, i. 
 
 610 
 hypothesis of elevation craters, i. 
 
 633 
 
 on glacier in Norway, i. 380 
 
 rents in volcanos, i. 614 
 
 volcanos of Greece, i. 592 
 
 eruption of Lancerote, ii. 64 
 
 raised marine strata in Sweden, 
 ii. 191 
 
 - rise of land in Sweden, ii. 185 
 Von Hoff on level of Caspian, i. 28 
 Von Liebig on Barren Island, ii. 74 
 Von Schrenck on migrations of animals, 
 
 i. 180 
 Vulcanists and Neptunists, i. 71 
 
 WALL, Mr., on pitch lake of Trinidad, 
 i. 414 
 
 Wallace, Alfred, on former connection 
 of Malay Islands, i. 250 
 
 deposition of Nile mud, i. 437 
 species, ii. 276, 278, 280 7 
 
 mind of man varying instead 
 of his body, ii. 471 
 
 southern character of Japan 
 
 snakes, ii. 343 
 
 zoological boundary in Malay 
 Archipelago, ii. 347, 352 
 
 Wallace, Alfred, on peculiar species of 
 Australian and Indian regions, ii. 349 
 
 Algerian species identical with 
 European, ii. 341 
 
 limits to variability of a spe- 
 cies, ii. 300 
 
 barriers to migration of ani- 
 mals, ii. 355 
 
 mammals of Java and Borneo, 
 ii. 346 
 
 Indo-Malayan and Papuan 
 
 races, ii. 474 
 
 annual increase and destruc- 
 tion of life, ii. 280 
 
 Lamarck's theory of volition, 
 ii. 281 
 
 domestic animals becoming 
 'feral,' ii. 304 
 
 Wallerius, theory of, i. 66 
 Wallich, Dr., on Ava fossils, i. 43 
 
 wood in peat near Calcutta, 
 i. 478 
 
 George, on life in deep seas, ii. 577 
 
 Waltershausen, Von, on Etna, ii. 2, 20 
 ' Warping,' land gained by, i. 569 
 Waste of coasts by action- of sea, i. 493- 
 
 561 
 Water, transporting power of, i. 347 j 
 
 action of running, i. 344-346 
 
 salt and fresh, agency of in volcanos, 
 ii. 223, 225 
 
 Waterhouse, Mr., on species of mar- 
 supials, ii. 332 
 
 Wave and retreat of sea, during Lisbon 
 earthquake, ii. 150 
 
 Webster, Dr., on rain-prints, i. 334 
 
 Weld, Mr. F., on New Zealand earth- 
 quake, ii. 87 
 
 Wells, Artesian. See Artesian Wells 
 
 Wener, Lake, horizontal Silurian strata 
 of, i. 315 
 
 Werner, his lectures, i. 68-70 
 
 on transition texture of rocks, i. 141 
 West Indies, active volcanos in, i. 584 
 
 Upper Miocene strata of, i. 201 
 West Indian earthquakes, ii. 146, 160 
 seeds floated to Azores by Gulf- 
 stream, ii. 419 
 Whales, migrations of, to north pole, i. 
 
 286 
 Wheat in mummies, of Egypt, identical 
 
 with living species, ii. 265 
 Whewell, Dr., on geological enquiry, i. 86 
 Whin Sill, long volcanic dike, i. 578 
 Whirlwinds, violent, during erruption in 
 
 Sumbawa, ii. 144 
 
 Whiston, his theory of the earth, i. 48 
 White Mountains, landslips in the, i. 351 
 Whitehurst, theory of, i. 66 
 
 on subsidence of Lisbon quay, ii. 148 
 Whitsunday Island, view of, ii. 585 
 
GENERAL INDEX. 
 
 649 
 
 W1L 
 
 Wilkinson, Sir Z. G., on sand-drifts of 
 Africa, ii. 507 
 
 deposits of Nile, i. 433 
 Williams, his opposition to Hutton, i. 81 
 Wilson, on Hindoo cosmogony, i. 6 
 Wind, sand drifted by, ii. 507 
 Winds, currents caused by the, i. 499 
 Winter in aphelion, effects of, i. 271 
 Winter, long and cold, in southern 
 
 hemisphere, i. 243 
 Wodehouse, Capt., on Graham Island, 
 
 ii. 59, 61 
 Wolf, extirpation of, in Great Britain by 
 
 man, ii. 455 
 Wollaston, Mr. J. V., on beetles of 
 
 Atlantic islands, ii. 416 
 
 landshells of Atlantic 
 islands, ii. 423 
 
 Wood, impregnated with salt water, 
 when sunk to great depth, ii. 525 
 
 Woodcock, seeds adhering to mud on 
 foot of, ii. 421 
 
 Woodward, theory of, i. 46, 106 
 
 Wrangel on upheaval of arctic land, i. 
 187 
 
 ZCT 
 
 Wreck register of lost ships, ii. 546 
 
 T7ANTHUS, the Lydian, his theory, i. 
 
 A 23 
 
 Xenophanes on marine fossils, i. 19 
 
 YAK, wild ox of Tibet, frozen in ice, 
 i. 190 
 
 Yarmouth, estuary silted up at, i. 516 
 Yarrell on varieties of gold fish, ii. 296 
 Yorkshire, waste of coast, i. 509 
 Young, Dr., on compression of matter 
 at the earth's centre, ii. 203 
 
 r7EALAND, NEW. See New Zealand. 
 Lt Zoological Provinces, ii. 329. See 
 
 Regions. 
 Zoophytes which form coral reefs, ii. 
 
 580, 602 
 
 Zuyder Zee, formation of, i. 553 
 great mosses on the site of, i. 551 
 
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