UC-NRLF THE LIBRARY OF THE UNIVERSITY OF CALIFORNIA PRESENTED BY PROF. CHARLES A. KOFOID AND MRS. PRUDENCE W. KOFOID GEOLOGICAL STORIES. /I GEOLOGICAL STORIES; A SERIES OF AUTOBIOGRAPHIES 'IN CHRONOLOGICAL ORDER. BY J. E. TAYLOR, PH.D., F.L.S., F.G.S , ETC. AUTHOR OF " HALF-HOURS AT THE SEASIDE," " HALF-HOURS IN THE G.1EKN LANES," " FLOWERS : THEIR ORIGIN, SHAPES, ETC.," "NATURE'S BYEPATHS," ETC. llhislniletl with *75 Woodcuts. NEW EDITION. LONDON GIBBINGS & COMPANY, LIMITED is, BVRY STREET, w.c. 1904. ; SB <*u PREFACE. THE " Stories" whose collection make up this little volume originally appeared in ' Science Gossip ' and other magazines. They are now arranged in their geological order, so that it has been attempted to give as simple and picturesque a view of the past history of the globe as possible. The favourable reception given to the " Stories " during their sepa- rate publication was an encouragement to their issue in the present form. The illustrations which now appear are an addition, and the matter which originally appeared has been corrected, and brought up to date as far as possible. The author knows that scientific men are too anxious to have their audiences increased to quarrel with any honest means by which that desired end may be brought about. In the publication of these " Stories," no better object has been in view than that of trying to make the number of people who were prejudiced against, or careless about, the grand deductions of Geology, interested in a science which is now influencing almost every department of modern thought. M358791 CONTENTS. CHAPTER I. THE STORY OF A PIECE OP GRANITE. pxoe Discussions on the origin of granite Plutonists and Xep- tunists Victory of the former Result of carrying the victory too far Mineralogical composition of granite Quartz, its component parts Alkaline ingredients probably assisted in its fluxion Felspar, what it is composed of Its "rottenness" Origin of Kaolin, or "China-clay" Mica, description of Hornblende, its colours, chemical composition, &c. Mineralogical relations of granite Porphyry, origin of its name Relation of ditto to other igneous rocks Syenite Protogine Pegmatite Binary granites Ternary ditto Quaternary ditto Their classification The first formed crust of the globe Idea as to the origin of the mctamorphic rocks Conditions under which granites were originally for- med Cavities in the quartz crystals of granite Heat and water concerned in origin of granite Pressure under which granite was formed Consequences of absence of pressure on igneous rocks The granites of the Highlands Pressure under which they were formed Ditto of the granites of Cornwall Difference of rock-pressure Great antiquity of the earth proved by above facts Granite probably formed of re-melted stratified rocks Deep-seated condition of latter Upheaval of granite nucleus of mountains How it is granite now occupies large areas The denudation of rocks formerly overlying granite outcrops Internal force of tho earth as opposed to that of the sun Overlying rocks strip- ped off by atmospheric agencies Time occupied . , . 1 13 Vlll CONTENTS. CHAPTER. IT, THE ST011Y OF A PIECE OF QUARTZ. Time as a factor in Geology Astronomical calculations Our notions of the earth's antiquity greatly expanded within last ten years The Cambrian per'od "Primary" rocks Pos- sibly older stratified rocks than any )et known Quartz rock, its external appearance Crystals of ditto Quartz and Qiiartzite Difference of ditto "Brazilian pebbles" The Archxan period the oldest yet known Composition of Quartz How difference in colour was effected Amethyst Topaz Cairngorms Jasper Flint Chalcedony Agates The metamorphic rocks Former notion of ditto Absence of fossils in ditto Notion as to the Cambrian period Altered rocks Cause of ditto Poverty of species of organic forms in older rocks What quartz originally was How formed The Eozoon, or "Dawn-animalcule" Organiza- tion of ditto Doubts concerning it Recollections of a Piece of Quartz Plumbago, or ''black lead" How formed Lowly organization of earlier land plants The Lanrcnthm limestones How they were probably formed Phosphates of lime Thickness of lower Laurentian rocks Changes during ' Laurentian period Elevation of marine deposits into dry land A period of submergence The upper Laurentian jocks How formed " Unconformability" illustratedIn- ferences from such phenomena Changes through which Laurentian rocks have passed Denudations of ditto In- trusions of igneous rocks in ditto Metamorphism of sand- stones, limestones, &c. Contortion of rocks .... 1-4 23 CHAPTER III. THE STOUT OF A PIECE OF SLATE. Locality of slate rocks Scenery of the Welsh mountains Original condition of latter Difference in mode of formation of sandstone and limestone rocks " Cleavage," what it is Probable cause of ditto "Joints "in slate rocks Contortions in Cambrian rocks Wear and tear of ditto Origin of the contortions, &c. Experiments on rock contortion The Pro- totoic period, what it was thought to be Age of Cambriun CONTENTS. IX TAGS rocks Fossils of ditto Laws of the succession of life-forms Lowly organization of Cambrian fauna and flora Thick- ness of Cambrian rocks Composition of ditto Evidences of shallow sea deposition How such a thickness of rock ma- terial could thus be formed Arencolites, or fos.sil worm- borings Ripple-marks in Cambrian strata Raiu-pittings and sun-cracks in ditto The first crustaceans Zoophytes of the Cambrian seas The Lower Cambrian formation as a group of rocks Break in continuity of Cambrian rocks Absence of a great limestone deposit AVhere latter will possibly be found The upper Cambrian rocks Lincjula Hugs The brachiopoclous mollusca Antiquity of certain forms of life Fossil shrimps Ancient sca-lilies Habits of ditto The Tr Mobiles Pteropods Why Cambrian fossils hie found as "casts'* Influx of higher forms of life The L'eplialopodous mollusca Orthoceratites Gasteropoda, or marine snails The Belleroplton -Paucity in specific types Progression of life system Inference from ditto . . 24 3(i CHAPTER IV. THE STOItY OF A PIECE OF LIMESTONE. Limestones common to every geological formation Generally of vllal origin Evidences of deep sea origin Characterized by abundance of marine organisms Sandstones contain more terrestrial ditto Silurian limestones in the "Black Country 1 ' The Wren's nest, Dudley Abundance of fossils Silurian limestones in America Origin of Petroleum, or "rock- oil " The Wenlock limestones Trilobiles, abundance of species of Alternations in stratification of Silurian recks Sliingle-beds Thickness of Silurian rocks Greater dis- tribution of sea areas Probable height of mountains The Lower Silurian rocks Evidences of volcanic disturb- ances The Ordorician strata, or Middle Silurian rocks May Hill sandstones Tarannon shales Upper Silu- rian rocks Their thickness. &c. Woolhope beds Wenlock limestones and shale Ludlow beds Aymes- try limestones Downton sandstones Marine animals of the Silurian period Orthoceratites " Sea-pens " Graptolitcs Structure of the Trilobiles Inferences of ditto X CONTENTS. MM Great change in physical geography during Middle Si- lurian period Thickness of volcanic lava and ash beds Al/undance of marine life during Upper Silurian times Pectens Univalves Cystideans The " chain-coral " Ancient coral reefs in Shropshire, &c. Favosites potymorpha Brachiopodous mollusca of Silurians First appearance of Vertebrate animals as fishes Ancient feeding-grounds of ditto The Ludlow " Bone-bed " Recent bone-bed off the Irish coasts Presence of fossil spores of cryptogamous plants in Ludlow bone-bed Inferences from ditto Origin of metal lodes Usual preponderance of gold in Silurian rocks, &c. 37 57 CHAPTER V. THE STOUY OF A PIECE OF SANDSTONE. Sandstone beds in every geological formation Psyclwmetry How sandstone rocks were originally formed The physical changes that have taken place since Principal agents in formation of sandstones Origin of Old Red Sandstone Cementing agents in sandstone rocks Free-stones and flag- stones The Devonian period Rocks of ditto in America, South Africa, Russia, Asia minor, and Australia Origin of the name Old Red Sandstone Thickness of dit^o Divisions of ditto Varying thickness in different localities Probable greater prevalence of Carbonic acid in atmosphere during Palxozoic epoch How the rocks were coloured red Ancient sea-weeds Huge Crustaceans Pterygotm "Age of fishes" Structure of first order that appeared, the Ganoids Rela- tion of ditto to existing species in America and elsewhere The Asterolepis Holoptychius Pfarii-hthys Ceplialaspis Coc- costens, &c. External peculiarities of ganoid fishes The Placofd fishes Onchus Fossil fishes of Caithness, &c. Shoa's of fossil fish How accumulated Reptilian characters of tome Devonian fishes Corals, Trilobites, &c. Differences in physical condition of old sea-bottom Chief localities of Devonian fossiliferous strata Total number of species The " Pilton group" Brachiopodous shells Spirifer Clymenia " Sun-corals," &c. Coloured fossil corals of Torquay, &c. Peculiar Trilobites of Devonian rocks Devonian rocks in Ireland Evidences of fresh-water deposition The " Irish CONTENTS. XI TAGS primitive Fern" (PaJxopteris Hibernicui) Its structure Other Devonian plants Sagenaria Psilophytcn Abund- ance of fossil fresh-water mussels (Anodonta) llemains of Crustacea Resembjanccs of Devonian lakes tj existing North American ditto 5878 CHAPTER VI. THE STORY OF A PIECE OF COAL. The piece of coal commences its history How many periods elapsed since it was formed Their names Physical con- ditions of Carboniferous period Reptiles of ditto Ancient coral reefs Formation of " Mountain " or Carboniferous Limestone Its abundance of fossils The principal species Nautilus Goniatites Gyroceras Orthoceras, size and habits of Abundance of ditto Shoals of Spirifera Their structure Carboniferous Trilobites Their last appearance The Crinoids Derbyshire enrrinilal limestones Polyzoa of Carboniferous period Fishes of ditto Megalichiliys Palxoniscus, &c. Foretts of later Carboniferous period Their appearance Principal v?getable forms of ditto Lepi- dodendra Sigillarias, &c. Gigantic Club-mosses Cat- amites, or gigantic "Horse-tails" Coniferous trees Fossil ferns Accumulation of vegetable materials Chemical changes in ditto Gradual change to present state as coal Microscopical revelations of coal- ash Changes through which carbon has passed Gradual transition from wood to anthracite Correlation of physical forces Light and heat of the Carboniferous period " bottled-up " in cml Colours of original plants, &c. Economical advantages of coal to mankind 79-113 CHAPTER VII. THE STORY OF A PIECE OF ROCK-SALT. Difference of story-teller from its fellows Natural origin of rock-salt Interval between Carboniferous and Triassic period occupied by the Permian Characters of latter Evidence of ancient Ice-action Permian " breccias " lie- X CONTENTS. FAQl semblance of its fossils to Carboniferoid forms Distribution of Rock-salt The New lied Sandstone, or "Trias" The brine-springs ot Cheshire Divisions or Trias Bunter sand- stone Muschelhalk, or " shelly limestone" of Germany Keuper beds A tolerably deep sea in Germany " Lily " Encrinite Reptilian fishes * ; Breaks " in geological con- tinuity Hallstadt and St. Cass'an beds " Unconform- ability " of members of the Trias Keuper beds those in which rock-salt found Cheshire stra*a Rock-salt and gypsum Thickness of strata Area of ditto Evidence of fish and reptile life No fossils in salt-beds An ancient "Dead Sea" Modern ditto The Keuper seas Fseu- domorphic crystals of suit Evidence of atmospherical and mechanical action Absence of vital ditto A " Dead Sea " in Cheshire and Worcestershire Origin of the Cheshire "meres" How Rock-salt was formed Dry-land appearance of Triassic age Great frog-like reptiles Lalyrinthodon Mhynchosaurus Feet-impressions on sandstone Long- fellow's " foot-prints " First appearance of mammalia Microlestes Its existing relations Rha;tic beds Ornithic affinities of reptiles South African Trias Its fossil reptiles Dicynodonls Flora of Triassic period Extinction of Palaeozoic forms 114 127 CHAPTER VIII. WHAT THE PIECE OF JET HAD TO SAY. Where jet occurs Lias beds Origin of jet Ditto of name "Lias" Straiigraphical appearance of Liassic sea The " struggle for life" Thickness of the Lias beds Division of ditto Lower Lias shales and limestones Dry land of the Liassic age Liassic flora Introduction of new forms The " Age of Reptiles " Ichthyosaurus Plesiosaurus Great land reptiles Flying Lizards Pterodactyles Physical geography of Lias si a Habits of marine lizaids Fish of Liassic era Lepidotus Vapedius ^chmodus Hybodu* Ancient sea-lilies Pentac.rinus Description of ditto Sea-bed of Lias period Abundance of Cephalopoda Ammo- nites Nautilus Belemnites, or " thunder-bolts " Nume- rical abundance of Ammonites Ditto of Belemnites Census CONTENTS. Xlll PAGB of Liassic fossils Brachiopods Last appearance of Spiri- fera Numerical proportions of Conchifera Gryplum IlippodiumAviculaj &c. Plants and insects of the Lias Continuity of the great Life-scheme The Plan of Creation . . ... 128145 CHAPTER IX. WHAT A PIECE OF TURBECK MAltBLE HAD TO SAY. Use made of Purbeck marble Its ecclesiastical importance What formation it belongs to The Oolite period Sub- divisions of Oolite rocks Extinction and continuity of specific forms Description of members of Oolite series Physical geography resulting from their distribution Geo- graphical changes during Oolitic era Oolitic coal shales near Scarborough Physical conditions of the ancient sea- beds Destruction of ancient cncrinites Dry land areas Ancient lakes Fossil fresh-water shells 1'lanoibis Palu- diua, &c. Accumulation of shelly limestones Purbeck marble, how originally formed "Coral ling" Ripple-marked flagstones Evidences of shallow water The great Oolite Thickness of entire series Fossils of the Oolite Their variety Description of Oolite seas Marine reptiles An- cient coral reefs Ancient ganoid fishes Mud-banks of Oolitic age The flying reptiles Terrestrial mammalia Their variety Flora of the Oolite Oolitic coal, how formed Oolitic iron-stone, how formed The Stonesfield slates Number of species of mammalia Marsupial animals Solen- hofen limestones Their richness in organic remains Cycads and Zamias Portland " Dirt-bed " How formed "Birds' nests" Great land reptiles Megalosaurus " Missing links " Bird-like affinities of Oolitic rcptilea How many of them were two-legged Compsognathus- - Fossil reptilian eggs Gradual development of Reptilia The first Bird Arclixopteryx, Its reptilian affinities Physical changes since the Oolitic period The Himalayahs All changes tending towards a higher condition of exis- tence . HG 166 XIV CONTENTS. CHAPTER X. THE STORY OF A PIECE OF CHALK. PA31 The minerals diffused in sea-water Marine animalcules The composition of their shells Enormous power of multi- plicationChalk composed mainly of microscopic shells The Globigerinx Their antiquity How chalk was formed Coccolitks Atlantic mud Changes along Cretaceous sea-bed Silica Ho\v flint was formed Flint-bands and nodules "Pot-stones" or Paramoudrx Cretaceous Echino- dernus Ananchytes, or "Fairy loaves" Micrasters Cidarids " Thunder-bolts," or Belemnites What they were Cretaceous Brachiopods Cretaceous fish Appearance of new orders A huge marine reptile Mosasaurus or Leidodon The Wealden series, how formed Its thickness Fossil remains of ditto Great land lizards Subdivisions of chalk strata Characteristic fossils of ditto Beauty of certain fossils How they have been preserved Evidences of up- heaval of ancient sea-bottom Slowness of the process The forces of nature Ancient sea-birds How the newly-raised land was peopled Geographical changes subsequent to de- position of chalk American strata and fossils . . 167102 CHAPTER XI. THE STORY OF A LUMP OF CLAY. Commonness of clay How old clay strata have been altered The Eocene period Difference between the London clay and the Boulder clays Circumstances under which the London clay was formed A tropical climate in Britain The commencement of the Tertiary epoch Thickness of the Eocene strata Description of ditto Their fossils Geo- graphical distribution of animals and plants The flora of the Eocene period Fossil fruits Indian scenery in Britain Mammalia of the Eocene period Palxotlieria Ganoid fishes Boa-constrictors in England Water-snakes Ano- vlo'horia Clixropotamus, or "river-hog" Dichobune JTywriodon "Missing links" Mollusca of Eocene period Their sub-tropical character Sharks of the period Turtleo CONTENTS. XV VAGB Duration of tho Eocene period Elevation of mountain chains Physical geography of the Eocene period Decrease in clinmture The register of the earth's crust . . . 193204 CHAPTER XII. THE ST011Y OF A PIECE OF LIGNITE. " Drown Coal," or Lignite, what it is Its appearance, &c. The Miocene period Great fresh-water lakes in Europe Luxuriant flora of the Miocene period Extent of ditto No ice-cap at the North Pole Connection of the Old and New Worlds Number of flower-bearing plants found fossilized Temperature of Miocene period Its probable cause An- cestry of living animals and plants Lignite beds in Europe, Asia, &c. Preservation of vegetable remains Cosmopolitan character of the Miocene flora The great number of ever- green plants Distribution of Miocene species The American character of fossil flora Smilax Dryandroidcs 1'roteacea Fan-palms Tulip-trees Magnolias, &c. Beauty of the Miocene landscapes Lignite beds of Bovcy Traccy Number of species of fossil plants denudation of the Dart- moor granite Miocene strata in Ireland and Scotland The last active volcanoes in the British Isles Lignite beds of Greenland, and what they teach Ditto of Iceland Ancient Miocene land Great fresh-water lakes in Switzerland Miocene strata of ditto Their fossils Fish, &c. Caddis- worms Indian butterflies Termites Various fossil insects Appearance of Quadrumana or monkeys in European woods The Dryopithecus Semnopithecus Fliopithecua Opossums in Europe Dinotheria Tapirs Mastodon Wart Hogs Hippopotami Wild Oxen Wild Deer The llipparion, or three-toed horse Miocene deposits in India " Missing links " again The Sivatherium The great Indian tortoise Giraffe and eamel in India Miocene horses in America Mastodons and elephants in ditto The long-armed monkey Volcanoes in Central France Up- heaval of sea-beds Formation of the Alps, Pyrenees, &c. Refrigeration of climature Formation of new sea- basins ... 207321 IV! CONTENTS. CHAPTER XIII. THE STORY OF THK " CRAGS." TAG! Meaning of the term " crag " Where these beds are found Their number The Pliocene period The Coralline, Red, and Norwich Crags Suffolk the bed of a tolerably deep sea Fauna of the Coralline Crag sea Ancient sea-urchins Where now living Time since Coralline Crag was formed Abundance of mollusca in Coralline Crag sea The As- tartes PedunculusCyprina Number of species of mol- iusca An ancient sea-bed, and what it teaches No " dredging " required " Sea Mats " Fascicularia Ex- tremes in Coralline Crag sea Marine currents The oldest crag Physical conditions of Pliocene period Migration of mollusca southerly Coralline Crag shells in West Indies Ditto in Mediterranean Thickness of Coralline Crag How formed The Red Crag Origin of name Denudations of Coralline Crag previous to it An ancient land surface in Suffolk and Norfolk How the ''coprolite" beds were formed Mollusca of the Red Crag " Southern " forms " Northern" ditto Refrigeration of climature Corals Cowrie shells False current bedding in Red Crag Physical geo- graphy of ditto The chalk of Norfolk A shallow estuary over site of Norwich Evidence of river communication The Norwich Crag Its fluvio-marine character Difference in fossils from previous crags Abundance of littoral shells Tellina Mactra Cerithium Fresh-water shells 7'/a- norbis, Paludlna Lymnea, &c. Land-snails Census of Norwich crag Ancient land-animals in Norfolk The Al- deby Crag Its fossils Increase of " Northerly " mollusca Evidence of rigorous climate The Upper Norwich Crag, and its lessons Pliocene and Pleistocene periods Analy- zation of shells of crags Number of extinct species in ditto The Belgium crags The " Box-stones" of Suffolk Their origin Evidence of a broken-up deposit Pliocene strata in Sicily English shells in ditto How they came there Evidence of volcanic disturbance Formation of Mount Etna Height of Pliocene beds on its flanks Refrigeration of climate in northern hemisphere Preparation for the long Arctic winter The introduction of the Glacial epoch 222237 CONTENTS. XV11 CHAPTER XIV. TJIK STOHY OF A liOULDKR. PAOE Its restless life The Glacial period Extent of Glacial de- po-its " Noah's Flood "The " Northern Drift "Connection of Tertiary life-forms with existing- species Sand, gravel, and clay Evidence of extreme cold Recapitulation of slow refrigeration of climate during 1 Tertiary epoch The Norfolk " Forest-bed "Its fauna and flora The bed of the German Ocean once a green wood Strange animals which lived in ditto An Arctic climate introduced into Britain England under a wintry sea Scotland and the north of England under an ice-sheet Greenlandic circumstances in Britain ' Description of Greenland glaciers Icebergs The Cromer cliff's Thickness of Lower Boulder Clay Iceberg action in drift The Atlantic sea-floor The Gulf stream Depth to which England was submerged How ascertained Moel Tryfaen An old sea-beach on ditto Re emergence of the land Arctic mollusca in British seas Raised sea-beaches Stranding of ancient Icebergs Dropping of large boulders Migration of Arctic plants The "chalky" Boulder Clay The "Heavy Lands," how formed Denudation of mud sheet into valleys Post-glacial deposits Ice-grooves and scratches England still connected with the Continent No straits of Dover yet formed The Mammoth The Hairy Rhinoceros Land connection with Ireland and England The Irish ElkThe Reindeer, Muskdeer Lemming, &c. Arctic plants living on British mountains How they got there, and when Glaciers in Scotland, Cumberland, Lan- cashire and Wales The Swiss glaciers The desert of Sahara once a sea English mollusca inhabiting it For- mation of the desert sands A warmer climate sets in Migration of existing fauna and flora Where from Separation of Ireland from England Of England from the Continent Bone caves Appearance of MAN Flint im- plements Migration and extinction of Mammoth, &c. - Formation of rich subsoils Results of the glacial period 238253 XViii CONTENTS. CHAPTER XV. THE STORY OF A GRAVEL PIT. The last of the race Incompleteness of the story Gravel- pits, and where Valley or river gravels HOW formed River terraces Difference in age of gravels How detected Peculiar appearance of pebbles in valley gravels Heights of former river levels Evidences of rigorous climate Valleys scooped out Evidences of man's first' appearance- Flint implements in river or valley gravels Proofs of their human workmanship The antiquity of man Identity of pattern in flint implements Paleolithic types of ditto con- temporaries of primitive man The Mammoth Woolly-haired Rhinoceros, &c. Why human bones not found with flint implements Roman and Saxon cemeteries Percolation of running water Teeth and tusks most enduring Stalag- jnite in limestones How it preserves fossils Human bones under ditto Kent's Cavern Evidence of human habitation of ditto The ''Reindeer" period Bone caves in Southern France Artistic attempts The Neolithic period How distinguished Stone weapons Distribution of Neolithic and Palaeolithic implements The Lake Dwellings Retrospect Evidence of Progression Development of cul- ture The Higher Life . . ... . . . 254272 SUMMARY OF PREVIOUS CHAPTERS . . 273 APPENDIX, giving Table of Rock Strata in British Islands Ex- planations and illustrations of geological terms, &c. Con- clusion .... 284 INDEX 293 GEOLOGICAL STOEIES. CHAPTER I. THE STORY OF A PIECE OF GRANITE. " We turned, we wound About the cliffs, the copses, out and in, Hammering and clinking, chattering stony names Of shale and hornblende, rag, and trap, and tuff, Amygdaloid and trachyte, till the sun Grew broader towards his death, and fell, and all The rosy heights came out above the lawns." TENNYSON'S Princess. 'HERE are few rock substances on the sur- face of the globe which have received more discussion and been more investi- gated than myself. I am somewhat proud of the attention I have received in this respect, for most of the leading geologists of every country, during the last century, have devoted themselves to the task of seeking out my antecedents. I am ac- quainted with a whole library of books, all most learnedly written, and various of them proving the reverse of the other, which have been penned on this inexhaustible subject. Even yet the question can hardly be regarded as finally settled. Every now 2 THE STOHY OF A PIECE OP GBANITE. and then some moot point or another crops up to engage the attention of philosophers, but, thanks to the progress of other sciences, the investigation of these is no longer confined to verbal expressions. It is not a little amusing to remember the hot discus- sions which were held over me at the beginning of the present century. Philosophers though they professed to be, the disputants resembled political squabblers more than anything else. One set de- clared I was born amid fire ; the other that I was of purely watery origin. Each party believed in their own ipsc dixit, and, as nothing could be absolutely proved, backed their own opinions by personalities. Somehow or other the former sect, who were called Plutonists, got the better of the latter, who were termed Neptunists. (The origin of these phrases my listeners will not find it difficult to understand.) But my Plutonic commentators carried their victory too far. Not content with proving that I was not a mere aqueous rock, they proceeded to declare I was nothing more nor less than one which had cooled down from a fused condition, something like iron slag ; nay, it was even urged that I was older than any other rock, and the theorists mapped out an idea which existed for many years afterwards, chiefly owing to its remarkable novelty showing how the whole universe was formerly one great cosmical fog ; that this diffused matter was con- densed into suns, planets, and satellites, each of which existed for ages in a molten condition, owing THE STORY OF A PIECE OF GRANITE. 3 to the heat evolved during the process of condensa- tion ; that the exterior of each planet cooled during the time which followed, and that granite formed part, or whole of this cooled envelope ! Such in brief was the orthodox notion of my birth, little more than a quarter of a century ago. Shall I enlighten my readers a little as to the nature of my mineralogical composition? I feel sure that most of them are acquainted with it already, but, if only for form's sake, I must go through with it again. My name is of Latin deri- vation, and was given me on account of the granular character presented by my different minerals. Gene- rally speaking, these are four in number Quavtz, Felspar, Mica, and Hornblende. Very frequently there are also traces of other minerals ; but these are the commonest, and in fact those which make up my bulk. The Quartz portion you may tell by its glassy appearance, and usually milk-white colour ; whilst another good test is its superior hardness. This mineral is almost pure silica, and is one of the most refrangible of known substances. It can with difficulty be -slightly dissolved in hot water, under great pressure ; whilst it requires a great deal of heat to melt it, and, generally speaking, some sort of flux to set it a-going. The next most abundant mineral in the constitution of myself and relatives (for our name is Legion) is that called Felspar. Your eye may detect it in my mass, by its pink or flesh-colour, whilst it is so soft that you may scratch 4= THE sTofctf OF A PIECE OF GBANITE!. it with your finger nail. It is owing to the unusual abundance of this mineral that I am sometimes so friable or " rotten," as the felspar decomposes and then causes the other minerals to fall asunder, just as the bricks of a wall would if all the cementing mortar were to decompose away. In many districts, as in Cornwall, where granite comes to the surface and has been subjected to atmospherical wear-and- tear for ages, it is not uncommon to find the fine felspar wasted into a newer deposit. Such is the well-known "kaolin,*' or China clay of commerce. The chemical composition of felspar is more com- plex than that of quartz. For instance, although its commonest elements are silica and alumina, the former the base of common sand, and the latter of clay, there are also contained in it more or less of soda and potash, lime, magnesia, and iron. Mica, the next commonest mineral I possess, is so well known as hardly to need description. All my listeners are surely familiar with the small, thin, silvery-looking scales contained in almost every piece of granite. Its ingredients are much like those of felspar, only differently mixed. Frequently Hornblende is a mineral entering into my compo- sition, when you will readily recognise it from its black or dark olive-green colour. When it is very abundant, it produces a rock varying from dark grey to black. A great number of what may be termed varieties of hornblende are known to mineralogists. Its chemical composition, generally speaking, is THE STORY OF A PIECE OP GKANITE. 5 about one-half silica, more than a quarter magnesia, and little more than half a quarter lime : besides these there are usually traces of iron, alumina, and fluoric acid. I mentioned above that I had many relatives, who were more or less nearly connected (I cannot say by blood, but by mineralogical similarity of composi- tion). These take various names, on account of their leading peculiarities. Among then: the com- monest is Porphyry, which takes its name from the purple variety used by the ancients in making vases, &c. This you may know from the large and distinct crystals, usually of felspar or quartz, which are imbedded in the granular matrix. Through porphyry granite passes into all sorts of allied igneous rocks, such as Clay stone-Porphyry, Clinkstone-Porphyry, Felspar-Porphyry, and so on. When hornblende takes the place of mica in the composition of granite, the latter goes by the name of Syenite ; when talc supplants mica, the result is called Protogine. A fine-grained compound of felspar and granite, with equally minute scales of mica, gives to you the varietal name of Pegmatite. According to the number of minerals entering into our composition, I and my relatives are roughly classed as Binary, Ternary, and Quaternary granites. All this detail of structure may sound very dry and tedious ; but it is absolutely necessary to go through with it, if my listeners wish to be more intimate with me. b THE STORY OF A L'lECE OF GEANITE. Although I have not a distinct recollection of my hirth (as, indeed, who has ?), yet I have more than a suspicion that such elements as soda, potash, lime, &c., greatly assisted as fluxes in bringing me into my original molten condition. I have mentioned the great number of relatives who claim near or distant kinship with me, and I have now only to remark that their affinity to myself has been deter- mined solely by the different circumstances attend- ing their origin. I- distinctly and utterly refute the idea that the first-formed crust of the globe was a granitic one ! I am fully persuaded it could not possibty have been granite, and I will give you my reasons by and by for this seemingly bold assertion. What that cooled crust was, I doubt if science will ever be able to discover. But the fact that it was not granite does not in the least invalidate the theory that every sun, planet, and satellite was con- densed from nebulous matter. This theory must rest on other grounds, and, singularly enough, ad- ditional facts are coming to its support every day. Men have not the slightest idea of what the primitive rock or crust of the globe was. The antiquated notion that it must have been granitic arose out of mistaken associations. It was found that, however old might be a stratified rock, whether containing fossils or not, some variety or another of granite was older still. Hence followed the hasty deduction, that originally one granitic crust encircled the fluid matter of the interior of the earth. It was thought THE STOBY OF A PIECE OF GRANITE. 7 that subsequent rocks were themselves formed out of the wear-and-tear of this granite, that the latter was in many places covered up by its own debris, and that the so-called metamorphic rocks were those first formed as stratified deposits, but altered to their present appearance through the intense heat of the newly-created seas, along whose bottoms they had been elaborated ! All this is wrong, and it behoves me now to descend from the region of pure hypothesis to that of fact. It is just possible, speaking generally of all the varieties of my family, that Protogine may be oldest. This, however, has never been thoroughly determined. One of my reasons for believing I could not have required any very great heat to reduce me to the molten condition, and that in this process the agency of water, as well as of heat, was necessary, is as follows : Many of the larger quartz crystals entering into my composition arc hollow. Frequently these hollows are more or less filled with water. Now it is a known fact that molten matter at a white heat requires its tempe- rature to be considerably lowered before it can even evaporate the water mechanically mixed with it. It has been recently shown that crystallized matter which has undergone pure igneous fusion, has usually cavities in its crystals, not containing water, but either stony matter or a kind of glass, and, in many cases, even a perfect vacuum. Hence the conclusion is arrived at that in the case of coarse-grained 8 THE STOBY OF A PIECE OF GRANITE. granite, containing much quartz, there is actually more proof of the action of water than of dry, igneous fusion. It is more than probable, therefore, that pressure, heat, and water combined, in the deeply-seated parts of the earth's crust, would cause the rocks to be reduced to a kind of paste, and that Fig. L Microscopic Section of Pitchstone, showing dendritic crystals. this paste, cooled under such circumstances, would be some variety of granite. I can hardly enter into the abstruse details of the deductions which have been made from the chemical and microscopical examinations of myself and relatives. Suffice it to say they result in proving that pressure, and this, THE STORY OF A PIECE OF GEANITE. 9 generally speaking, of overlying rocks stratified or otherwise, is a preliminary and indispensable neces- sity to the formation of granite; that, if pressure be absent or less than that required, notwithstand- ing all the other requirements may be present such as heat, similarity of mineral ingredients, &c. Fig. 2. Microscopic Section of artificial Porphyrino, showing ditto. such a resulting igneous rock would not be granite ! It might be a variety of porphyry, or basalt, or greenstone, or, if all pressure were re.- moved, and the molten matter allowed to cool in the open air, simply ordinary Lava ! From a micro- scopical examination of various granites, it has been 10 THE STOBY OP A PIECE OF GBANIT3. shown that those of the Highlands of Scotland indicate their having been formed under no less a pressure than twenty-six thousand feet of overlying rocks more than were the granites of Cornwall. There is good reason for believing the latter to have required at least forty thousand feet of rock-pressure ; so, in that case, the granites of the Highlands must have been formed when sixty -six thousand feet of overlying rocks were piled above them ! One is naturally astounded by the magnitude of these operations, but I assure you there is little doubt as to the general correctness of the deductions. In this way the mineralogical construction of myself and others supplements the teaching of organic remains, as to the immense antiquity of the globe ! Nothing short of an eternity of time would have sufficed for all the changes which have been rung upon it. There is reason to believe that many of my granitic relations are nothing more or less than re-melted stratified rocks, with their enclosed fossils ! As these rocks have been slowly depressed or sub- merged, so as to bring the lowest-seated portions within the influence of the earth's internal heat, they have been first metamorphosed into a similar condition to gneiss and mica-schist, and, if the sinking went on, have passed through this stage into that pasty condition which deprived them of all stratified structure, and converted them into what I am myself ! Then succeeded a reversal of the move- ment; so that this granite would be thrust slowly THE STORY OF A PIECE OF GRANITE. 11 upwards with all the overlying strata piled above it. The movement went on until these were tilted into a continuous mountain-chain, or high and extensive table-lands. Meantime the granite nucleus would form the heart of such mountains, the strata dipping away on each side, as in the Himalayas. I fancy I hear some of my listeners remarking "But if granite can only be formed under such immense pressure, how is it we find such large areas of country where nothing else is to be seen?" In the answer to this we have the gist of the argument, and I would respectfully ask the special attention of my audience to it. Let them ask themselves where the materials come from to form the Laurentian, Cambrian, Silurian, Devonian, and, in short, all the other subsequent formations ? They could only have been formed out of the waste of still older and already solidified rocks. Each formation, therefore, represents the amount of wear-and-tear which went on during the period when it was deposited. If there had been no compensation against this levelling process, all the highest grounds would soon have been worn down to a common level, and the elabo- ration of more recent deposits been self-checked. But each succeeding formation shows that this was not the case, and indicates that the physical arrange- ments of our planet have been much the same through all time to what they are at present ; that atmospherical and marine wear-and-tear were coun- terbalanced by upheaval from beneath; that the 12 THE STORY OF A PIECE OP GEANITE. external force emanating from the sun and resulting in all these atmospherical effects, was exactly ad- justed by the native force of the earth, exerted from the interior outwards. These two have exactly checked each other from the beginning, otherwise the great life-scheme of our globe would never have had time for its development ! I hope I have been successful in explaining a great Section showing Granite nucleus, with strata lying on its flanks, the overlapping and continuous portions of which have been denuded off. difficulty, and that my listeners now see the reason why I and my relatives come to the surface. It is because the rocks ivhich overlay me at my birth have since been stripped off, and slowly removed by atmo- spheric and other agencies. All the formations which were then piled above me, are to be found in strati- fied rocks of later date ; therefore, the period of my birth is not limited to any particular geological STORY OP A PIECE OP GKANlTE. 13 epoch. I am found at the surface, surrounded by rocks of every age, even including those of the Tertiary. Wherever the pent-up force of the earth's interior has thrust us up, there have we slowly elevated the rocks lying upon us. In many cases this elevation has been so slow that it has hardly exceeded the rapidity with which these overlying rocks have been gradually worn away ! Think of the vast antiquity of the earth's crust, as indicated by these facts alone ! Since the granites of the Highlands of Scotland were formed, twelve miles of overlying material must have been removed ! Where has. it all gone to ? Ask the ninteen miles in thickness of the known stratified rocks, all of which have probably been formed since that granite itself. You scarcely need be afraid of Time, when you have Eternity to draw upon ! 14 THE STORY OF A PIECE OF QUARTZ. CHAPTER II. THE STORY OF A PIECE OF QUARTZ. "God worketh slowly; and a thousand years 1 He takes to lift His hand off. Layer on layer He made earth, fashioned it and hardened it Into the great, bright, useful thing it is ; Its seas, life-crowded, and soul-hallowed lands He girded with the girdle of the sun, That set its bosom glowing like love's own Breathless embrace, close-clinging as for life ; Veined it with gold, and dusted it with gems, Lined it with fire, and round its heart-fire bowed Eock-ribs unbreakable; until at last Earth took her shining station as a star, In heaven's dark hall, high up the crowd of worlds." BAILEY'S Festus. ACT," they say, " is often stranger than fiction." I do not think you will find this old saw better illus- trated in the whole series of geological teachings than in my own history. That history is connected with one of the grandest discoveries of late years, inasmuch as it carries back the antiquity of the globe even beyond the mighty ages which had already been claimed for it. Indeed the practical effect of this is to show the geologist that time, as a factor, has nothing to do with his investigations. That simple relation in the succession of events is all THE STORY OF A PIECE OF QUARTZ. 15 he can safely arrive at ; and that his finite mind can no more conceive of the myriads of years which are included in the world's biography, than it can sum up in human arithmetic the stars and systems which crowd the illimitable realms of space ! Within the last ten years a clearer geological knowledge of my origin has caused geologists almost to double the already known antiquity of the earth. At the time I mention, or thereabout, it was usually under- stood that the Cambrian period was the oldest and most primeval. The human mind is essentially conservative, and although geologists reasonably claim to be more catholic than most men, they are under the same influences. This is indicated by their unwillingness to make the world appear older than they possibly could help. Hence such terms as ''Primary," "Primordial," &c., applied to the ancient strata which nevertheless are all much younger than myself are so many landmarks which have shown this tendency in the human mind. It may be, that although the geological formation to which I belong is undoubtedly the oldest known at present, in any country, subsequent research may eventually make known an older period still. The difficulty in doing so, however, will be consi- derably heightened by the fact of all these oldest rocks having passed through many changes, by heat and chemical action, so that nearly all traces of their former fossils are effaced, and thus they are reduced to a similarity of mineral condition all the world over. 16 TfiE STORY OF A PIECE OF QUARTZ. There are few of my readers who are not ac- quainted with my general appearance. They have gathered me as a milk-white pebble by the sea- beach, or have admired me as they climbed the Scotch mountains and saw me sticking out of the contorted rocks like a huge white rib. Or, they may have been more pleased still with the geometrical shapes which my substance is capable of assuming as a six-sided, pointed crystal. It is of my former state, rather than of my latter, that I intend now more particularly to - speak. And yet it is necessary forme to say that there are two common conditions in which I am usually to be found. One is as Quartz, the other as Quartzite. These terms are merely significant of appearance, and include little or nothing of chemical difference. Quartz proper is usually found in veins, having been forced into fissures when it was in a soft, heated condition. Quartzite has not so completely lost all its original structure, and its particles or grains may often be seen retaining their original water- worn form. Again, Quartzite does not occur as an intrusive rock, but in huge stratified masses, hundreds of feet in thickness. And yet you may find transitions in these two extreme states of my family even from the transparent crystal condition of the " Brazilian pebbles" to the coarse-grained and resinous appear- ance of quartzite. Let me be thoroughly understood. Although I am representing that great, and at present oldest, THE STORY OF A PIECE OF QUARTZ. 17 epoch in our planet's history the Laurentian I should not like you to fall into the mistake of sup- posing that I am limited to it alone. On the con- trary, formations of much more modern date than that to which I helong are rich in quartz veins and even heds. In short, any rock that has heen ex- posed to the same influences as myself, if it con- tained the same chemical substances, would also become quartz as the result. They tell me that I am chemically composed of only one substance Silica. My normal condition is transparent and colourless, although I am rarely found like this except when in geometrically-shaped crystals. A milk-white colour is that which I commonly affect, and this is due solely to the rate at which my parent mass cooled down. Hence it is that geologists can more or less tell from my appearance the circum- stances which attended my birth. From the pure, transparent condition I mentioned above, I pass through a great many modifications, and in each stage of these I am known by different names. But with the exception of very slight mixtures of other ingredients than this silica, I continue the same throughout ; thus, when I am of a violet tint I am called Amethyst ; when of the colour of sherry, Topaz ; when of a smoke-brown hue, Cairn- gorm, &c. Mixed with other chemical substances I pass into jasper, flint, chalcedony, agates, &c., in all of which you will find that the largest portion of their whole bulk is silica. c 18 THE STORY OP A PIECE OF QUARTZ. Up to the time when the geological formation to which I belong had been discovered, as I before remarked, the Cambrian was looked upon as the oldest. But there were a series of schists, quartzose rocks, &c., which were still older than these, and which usually went by the name of Mctamorphic, or " altered " rocks ; thus committing them to no par- ticular geological age. By many these rocks were regarded as transitional, that is, as passing from an igneous to a stratified condition. When it was imagined that all the granite rocks were formed as the outer crust of a once molten globe, then it was also thought that the rocks which were formed along the bottoms of the hot seas must be of a very peculiar character. In short, these mica-schist, quartz, and gneissose strata were regarded as having been deposited and solidified under such circum- stances. Their absence of fossils, and proofs of having experienced great heat, were thought to bear out this view. I hardly need tell you how erroneous it was. The Cambrian period was believed to be that when Life first appeared on the Globe. Now this supposition is known to be as wrong as that which accounted for the mineralogical appearances of the metamorphic rocks. Although I am speaking only as a humble piece of quartz, you must remember that, when I am narrating the circumstances of my life, I am at the same time giving those of the mica-schist, gneiss, and altered limestones, which, equally with myself, THE STORY OF A PIECE OF QUARTZ. 19 belong to the Laurcntian epoch. Indeed the last- named rock, greatly altered though it is in appear- ance, so as to resemble loaf-sugar, could, perhaps, tell you more of the vital conditions of the ancient Laurentian seas than I can. First, let me impress you with the fact that when we were formed, collectively, we did not differ in appearance from the sandstones, clays, and limestones of either the present or of any bygone geological era. All this wonderful alteration in our appearance and structure is due solely to the subsequent changes we under- went. Of these I shall speak presently. If you know anything of the great deductions of geology, you will be aware that the farther you go back in time, the fewer and simpler are the forms of life which inhabited the earth. It was the general poverty of species, accompanied by their lowly organization, which caused the Cambrian epoch to be regarded as the first platform of Life. Now when you go farther back in time, to my own age, you will find that the organisms are still lowlier. Indeed, of the objects that lived in the seas where I was originally deposited as a thick sheet of ordi- nary sand, all that I can remember is one abundant organism now known as Kozoon, or the " dawn- animalcule," in allusion to its primeval antiquity. It was lowly enough organized, being little above the natural history rank of the common sponge. This marine creature lived on the sea-bottom in vast quantities, and there grew by the addition of layer 20 THE STORY OP A PIECE OF QUARTZ. on layer of younger forms, just, as I am told, is the way in which coral reefs grow in modern seas ! Like the latter, it ahsorbed its carbonate of lime from the sea-water, and thus caused great masses slowly to accumulate. This was in the deeper parts of the sea, where the water was clear, and free from muddy sediment. But my recollection goes no far- ther to any animal type. No fishes swam in the blue water ; no crustacean crawled over where I lay ! Occasionally the rivers brought some lowly-organized vegetables in entangled masses, or sea-weeds drifted into my neighbourhood, and eventually became entombed in the sandy mud my then condition. An impure coal was thus formed, and when the rocks underwent their great transformation by the agency of heat, this vegetation somehow or another passed into Plumbago, or "black-lead," as it is commonly and erroneously called. The great amount of carbon more than there is in many kinds of actual coal which makes up the composition of plumbago, had long indicated its vegetable origin. How lowly organized were the land plants of the Laurentian period you may guess at from the fact that many ages afterwards, during the Carboniferous epoch, they existed only as gigantic club-mosses ! What I have said about the vegetable origin of " black- lead " applies as logically to the origin of the Laurentian limestones. Some of the beds are as much as fifteen hundred feet in thickness, but altered throughout. As geologists are now aware, THE STOKY OF A PIECE OP QUARTZ. 21 the limestones in every other formation are always of vital origin that is, they have been formed by the accumulation of coral reefs, shells, &c., cemented, perhaps, by a still greater bulk of microscopic organisms. The white chalk of Norfolk is nearly as thick as one of these beds of Laurentian lime- stones, and yet, to the naked eye, it offers no ex- planation of its origin. It is not until you have applied the microscope that you perceive it to be almost entirely built up of the shields of animalcula, some of them of the same species as are still living in the Atlantic ! If, therefore, the limestones of every known geological period have been formed by vital agency, one would imagine that those limestones, whose organic remains had been oblite- rated by the great heat to which they have been subjected, might be reasonably put down to the same origin. Again, the various phosphates, &c., found in these altered limestones, plainly tell of animal life having been employed in elaborating them. But, mighty though the transitions have been through which the whole of the Laurentian rocks have passed, all traces of fossils have not been lost. The limestones yet contain myriads of Eozoa, as plainly showing they were formed by its agency, as a coral reef tells you how its bulk grew to its present size. Twenty thousand feet of material had been strewn along the bottoms of the Laurentian seas in various places, the material varying according to its neigh- 22 THE STORY OF A PIECE OP QUARTZ. bourhood to the mouths of rivers, &c., whence it was brought. The solidification of this mass took place at the same time as its deposition. A great plutonic change then occurred, and what had been sea- bottom for ages, eventually became dry land. Then followed a period of submergence, when it was once more sea-bottom, and had piled over it ten thousand feet of extra material! You ask how I know all this, and I reply by pointing to you how the upper ten thousand feet of rock lie un conformably on the lower masses* By ." unconformability " I mean that the dip of their beds is not the same, the lower being different from the upper. This plainly shows that the lower beds were uptilted before the upper were formed, and that both series partook of the movement which finally elevated the upper Lauren- tian beds into dry land, in which state they remained during the subsequent Cambrian epoch. You can readily understand how the Laurentian rocks, being the first formed, must have undergone more changes than any other, inasmuch as they have had to partake of all that has gone on since they originated. It is a wonder that we now find any of them uncovered by rocks of subsequent date ; nor should we, had it not been for those great atmo- spherical denudations which have stripped off miles in thickness of overlying rocks, so as to expose those of an older date. The Laurentian strata have had, perhaps, miles in thickness of the rocks of other formations piled above them. They have had to THE STORY OF A PIECE OF QUARTZ. 23 undergo those great depressions which eventually brought them so much under the influence of the earth's internal heat. Masses of granite, trap, porphyry, &c., have been intruded through them, and thus they have been squeezed and contorted in the most fantastic manner. The sandstones, some of them five hundred feet in thickness, have been so affected by heat as to become quartz, or quart zite. Here, then, you have the secret of my origin the whole history of the changes which brought about my present appearance ! The limestones that were contemporaneous with myself were altered so as to resemble loaf-sugar, and had all, or nearly all, their organic remains obliterated. The shales and slates became transformed by heat, chemical change, and pressure, into mica-scldsts, gneiss, fclstoncs, c. So that the very peculiarity in dip, contortion, absence of fossils, and mineralogical changes, which mark all the rocks of the Laurentian age, tell of their vast antiquity ; whilst the similarity in composition of these rocks in all parts of the world, in Ireland, Scotland, and North America, as well as the preva- lence of similar lowly-organized fossils in their lime- stones, indicate they have passed through the same transformations since they were contemporaneously deposited as limy muds, sands, and clays along the floors of the primeval seas ! 24: THE STOEY OP A PIECE OF SLATE. CHAPTER III. TUB STOKY OF A PIECE OF SLATE. " It is a lonely place, and at the side Kises a mountain rock in rugged pride; And in that rock are shapes of shells, and forms Of creatures in old worlds, and nameless worms Whole generations lived and died, ere man, A worm of other class, to crawl began." CRABBE. WAS not always what you now see me. Far, far back in that almost infinite past, which geology claims before it can explain its phenomena, I was lying along the bottom of a tolerably shallow sea, as part of an extended sheet of fine mud. My birthplace is registered in the heart of the North Welsh mountains, and the for- mation to which I belong goes by the name of the Cambrian. Its rocks form some of the grandest scenery in the world. Steep precipices, on which grow rare ferns arid wild plants, frequently too tempting to the botanical student, are the result of succeeding dislocations, jointings, and bedding. Mountain streams brawl over them; and waterfalls, whose substance is evaporated into- prismatic mists, pitch from the precipices of these Cambrian hills. Fre- THE STOBY OF A PIECE OF SLATE. 25 quently the rocks are so hard and bare, that even the lichen and moss fail to obtain foothold, and so the naked slate shines in the varying sunlight in coloured shades from pink to deep blue. Here, with the gathering cumuli, ring-like crowning their peaks, the Welsh hills stand forth in all their characteristic grandeur. No wonder that crowds of tourists should strive to forget the cares of business, and endeavour to get a mouthful of purer air, whilst climbing their steep sides ! It requires some faith in geology to carry the mind definitely backwards to the time when these rugged hills were extended sheets of marine mud! But no mathematical deduction is more certain. You never find clay or sandstone rocks so full of fossils as limestones, for the simple reason that the former are of mechanical origin, and the occurrence of organic remains is therefore accidental. Whereas limestones are of vital origin, resulting from organic agencies almost entirely. You examine the slate rocks of which I am a humble representative. Their colour and general texture you easily recognize from the too familiar appearance of the London housetops. But, when in position, you are scarcely prepared to find that what you had imagined to be the result of bedding or lamination in the slates is actually due to what is termed cleavage. This is a peculiar feature about thin-bedded, argillaceous or clayey rocks, that they undergo, when subjected to pressure, and perhaps 26 THE STOEY OP A PIECE OF SLATE. heat as well, a certain change, which causes every particle to change its position. By virtue of this process, the rock splits not so readily along the lines of stratification as along that of the cleavage, or planes where the material has been re-arranged. In addition to this structure, which is frequently diagonally across the line of stratification, these slate rocks are broken up into large cubic masses, caused by great joints traversing the rocks, irre- spective of any previous alterations. Fig. 4. Showing foldings in strata. The stratification itself is not horizontal, bat frequently pitched up at a very steep angle, and commonly the rocks are contorted into a series of ribbon-like foldings. After all this cleavage, jointing, dislocation, and faulting, the solid rocks have been subjected to thousands of centuries of atmospheric and marine wear-and-tear ! Can it be wondered at, therefore, that there should result from all these combined agencies, continued through untold millenniums, all that wildness and grandeur of physical scenery which distinguish these old Cambrian rocks wherever they are met with? THE ST011Y OF A PIECE OF SLATE. 27 The old rocks, especially those of an argillaceous character, are nearly always marked by contortions, to which those of a later date are strangers. It is from amidst them also that we have great bosses of granite coming to the surface, the contorted slate rocks surrounding them on every side. How is this ? I will endeavour to explain. My hot-tempered friend, the piece of granite, told you how it was absolutely necessary to his origin that the molten rock of which he was portion should be overtopped by a tremendous thickness of material when it was cooling. This my own experience will bear out. The contortions which characterize my family equally required an amount of overlying material to be piled upon them, or they could not have arrived at such singular ap- pearances. A mass of half-hardened rock, if displaced by a foreign body, such as a boss of granite being thrust up, would rise up as one great hill or mountain. But if there was sufficient pressure overlying the formation thus disturbed, then it would be thrown into a series of foldings, in order to make place for the laterally-intruded material. Of course the whole exterior surface would then be elevated ; but this elevation would not be in a conical form, but along a large tract of country. In geological books you will find how, on a small scale, this experiment has been conducted. A series of layers of cloth has been formed ; pressure was 28 THE STOEY OF A PIECE OP SLATE. applied to the sides, when the surface naturally rose into a sort of mound; but the moment a heavy weight was laid on the top cloth (thus representing the overlying material of which I spoke), then the layers of cloth, when pressed at the sides, became folded up into a series of contortions. My hearers will now see why granite outcrops should frequently be the companions of slaty contortions ; for the agency of overlying rock-masses, which originated the former, by their pressing weight caused the latter, when disturbed, to assume the wrinkled, fan- tastic shapes they now present ! It is not long since the Cambrian formation was deemed the oldest in the world ; even its most learned and indefatigable observer called it the Protozoic, imagining its organic remains to be the " first life-forms." This provisional place of honour, however, has since been bestowed on a still older, and of course even a more contorted and meta- morphosed class of rocks, termed Laurentian. Whether this in its turn will have to give place to one older still I cannot tell ; but this I know, that the more you study the rocks and their con- tained fossils in the field, the more will you be convinced of the enormous antiquity of the earth, and of the incalculable period during which life has been divinely manifested upon it ! Human arith- metic will never be able to compute my own age, and therefore the very attempt would be futile. Seeing that we slate rocks are, as far as England is THE STORY OP A PIECE OF SLATE. 29 concerned, the oldest known, who can wonder we should be found in such a dislocated and contorted condition ? Have we not had to bear the heat and burden of the day ? All the rocks of later date have been uplifted into dry land from the sea-bottoms on which they were formed ; and seeing we were older, it was impossible to elevate them without also raising us at the same time ; so that the alter- nate elevations and depressions to which we have been subjected are innumerable. Meantime the overlying formations have been slowly eaten away, attacked either by atmospherical forces or by marine denudation. Far distant though the period of my birth may be, I have a lively recollection thereof. I am well provided with " hints to memory," in the shape of fossils impressed on, or included in, my parent bulk. I have only to turn to these, and immediately the old life-scene vividly recurs to me. What a strange time it was, and how different to anything I have since beheld ! I can readily understand how the earlier geologists should reverently regard our fossils as the first created. In them Nature seems almost to have "tried her 'prentis han' ; " for these earlier organisms bear about them the impress of a lowlier fauna. Not that any are found which cannot be referred to existing natural-history orders, for Nature, like her Lord, knows " no variableness, or shadow of turning." Her plan has been to fill up the outline, and this has been slowly consummating 30 THE STORY OF A PIECE OF SLATE. during the unknown ages which have elapsed since the Cambrian period. Hence it is that the further you go back in time, the more simple is the fades, or general appearance, both of animals and plants. It is possible that, at the time I was born, the dry land was parsely covered with a humble flora; but it will be evident that as I am of purely marine origin, I cannot speak with certainty of what took place elsew T here. I have a dim recollection, how- ever, of certain obscure mosses, lichens, and perhaps reeds, but nothing 'more certain. That there was dry land, and that this dry land was watered by extensive rivers, I have not the slightest doubt. Otherwise, where would the materials have been derived which make up the bulk of my parent formation ? And, that this material was slowly, and not rapidly obtained, you yourselves may easily see from the fineness of the particles which enter into my composition. For the Cambrian forma- tion is no less than eighteen thousand feet in thick- ness ; and, with the exception of certain beds in the middle of this immense bulk (called by geologists respectively Harlech grits and Lingula flags) the rocks of this period are principally fine-grained slates. Even the grit-stones and flag-stones afore- mentioned which are not of a very coarse texture, bear witness to the slowness of their deposition. I believe the whole of this formation was deposited in tolerably shallow water, not near so deep as the present Atlantic. Perhaps you ask how it was, THE STORY OF A PIECE OF SLATE. 31 then, that the strata of a formation nearly three and a half miles in thickness could be deposited in only a tolerably shallow sea? The question is natural enough, and I reply by stating that whilst these strata were slowly forming, the sea-bottom was as slowly subsiding. Hence it remained at almost the same depth during the long period when these fine muds were thrown down. You will find my statement verified by the fact that in the Lower Cambrian (in a group called the Longmynds) the tracks, holes, &c., of marine worms (termed Arcnco- litcs) are found distributed through a vertical thick- ness of over a mile of rock. Nor are these humble organic remains scarce ; they occur in countless myriads. After the deposition of the Lower Cam- brian rocks, as far as I can recollect, the sea began to get deeper; the deposits formed along its bottom did not quite equal the rate of depression, and so the depth of water increased ; but before then I well remember how comparatively shallow the sea was. This is attested not only by the countless fossil worms which have won a geological immortality from the trails they left on these early sea-bottoms ; but also from the ripple -marks which equally characterize the same set of strata. Nay, we have even evidence of extensive mud-flats, for many of the beds are pitted with rain-drops, and marked with sun-cracks. Thus, far back as English geology can take you, you have evidence of exactly the same kind of meteorological agencies as those which now regu- 32 THE STORY OF A PIECE OP SLATE. late the physical well-being of the external globe. Cloud and sunshine are testified to by these sun- cracks and ripple-marks. Vapours were raised by solar heat then as now, and the " bow was set in the cloud," although not as yet selected as a covenant to man ! In the same beds as these ripple-marks, sun- cracks, rain-pittings, and worm-tracks, we have innumerable remains of a small crustacean (Palceo- pyge), which used to flit through the shallow water in dense shoals. A pretty little zoophyte (Oldhamia) lived in quiet, sheltered spots, where it luxuriated abundantly, its little branched stems forming miniature forests along the old sea-bottom. These lowly creatures are almost all I remember of what is called the Lower Cambrian formation. The upper portion, however, is much richer in fossils ; and well do I remember when these now petrified organisms enjoyed the pleasures of animal life. Between the deposition of the strata of these upper and lower formations there was a break in the locality where I was born. Probably somewhere else in the globe there will be found a formation (possibly limestone) which was elaborated during this provisional rest. Of that, however, I can only conjecture. Concerning the animals which lived in the Upper Cambrian seas, I can speak more posi- tively. They were, first of all, far more abundant, both in species and individuals. Thus the basement rocks of this subdivision go by the name of Lingula THE STORY OF A PIECE OF SLATE. 33 flags, from the vast quantities of the fossil of tLat name occurring in them. The Lingula was a mol- lusk occupying the lowest class among shell-fish, that termed Brackiopodous, or " arm-footed," from the peculiar arrangement of the breathing organs. Strange enough, this genus is still in existence, and you can hardly tell the difference between the horny shells of the living species and those which lived at this early epoch. Talk about genealogy ; no other family, except that of the ma- rine worms, can claim an antiquity so vast. Not- withstanding all the mutations through which the surface of our old world has passed the upheaval of sea-bottoms into mountain-heights, the depression of mountains into sea-bottoms this one genus of shell-fish has triumphantly survived them all ! It is now, I am told, fast passing into extinction, the final lot to which so many genera of subsequent date have succumbed. Among other animals which lived at the time was a species of shrimp (Hymenocaris), whose remains may be met with in the same rocks. Along this sea-bottom, in various places, lived colo- nies of a kind of sea-lily, or rather, of an animal halfway between them and the more recent sea- urchins : these now go by the name of Cystideans. Furnished with a short footstalk, which served to anchor them to their selected habitats, they flourished on the lower forms of life which swarmed in the waters of these primeval seas. Later on was introduced a crustacean afterwards THE STORY OF A PIECE OF SLATE. Fig. 5. to become famous, both for its abundance and the number of generic and specific forms it assumed. This was the well-known Trilobite. Several gen- era, and still more nu- merous species, were in existence, and so fast did the newly-introduced species breed, that they soon became the chief inhabitants of these early seas. Most of my listeners are acquainted with their tri-lobed forms (whence their name), and have admired the jointed coat of mail which protected them, and, at the same time, gave them all the necessary flexibility for movement. Out in the deeper water lived a neculiar Cambrian Trilobite (Paradoxides Bohemicus). kind of mollusk, whose type is still living. This is termed Theca, and its external protection consisted in a thin, almost glassy case ; not so fragile, however, but that it has been carefully fossilized. But in gritty sandstones, or coarse slates, it is rare you will find any remains THE STORY OF A PIECE OF SLATE. 35 of the old calcareous shell of the various creatures I have named. Subsequent changes, most of all the percolation of carbonated water, have removed the limy material, so that the fossils found are princi- pally as casts. Perhaps the lime thus removed has, in many cases, served as a natural cement to the sandy or clayey particles, so that much of the hard- ness which now characterizes these rocks may be originally due to the limy substance of the Cambrian .inhabitants. Towards the close of this remarkable period, other forms of life appeared, the total number of genera and species considerably increasing. Shell-fish of a higher grade were introduced, until the highest type the Cephalopoda was brought on the stage of existence in the shape of OrtTioceratites. These were allied to the living nautilus, only they had straight cham- bered shells, instead of coiled ones. Their arms, something like those of a cuttle-fish, extended out of the last, or body-chamber ; and on these, with their shell inverted like a spire, the creature would occa- sionally crawl over the muddy sea-bottom, where I was slowly forming. Belly-footed mollusca (Gas- teropoda), in the shape of a genus which has been extinct since the time of the coal formation, crawled about, their gracefully coiled shells bein as beautiful as any of their recent representatives Thus did the Cambrian period come to a final close. Qf course my listeners cannot expect one poor 36 THE STORY OF A PIECE OF SLATE. memory accurately to remember all the types of life then existing ! Suffice it to say that, compared with those of subsequent periods, they were few and of a much lowlier kind : numerical abundance of individuals made up for poverty of genera and species. It was the dawn of life when organisms were in the cradle. Betwixt this and chaos was a great gulf fixed. The first outlines of that grand scheme which should ultimately link inorganic matter with spirit were then rudely sketched. Time was ordained for the sole purpose of filling them up, and, when the object is completed, time shall be no longer ! Even since this distant period, life has progressed until it has reached its physio- logical maximum in man. But in him, I am told, appear the germs of a new spiritual life, whose de- velopment shall extend into the future, just as organic life has been developed in the past ! Such are a few of the reminiscences of a piece of slate ! Of the agencies which uplifted me into a mountain- ridge, which consolidated the fine mud where I was born into hard slate, I cannot tell. These are all included in those chemical and geological changes which took place after my birth. But, whilst I have thus endeavoured to administer to the intel- lectual curiosity of man, I cannot forget that it is to these subsequent alterations that I am what I am, and that I now assist in roofing in and protect- ing the latest introduction of nature in the form of man ! THE STOUY OF A 1'lEiJE OF LIMESTONE. 37 CHAPTER IV. THE STORY OF A PIECE OF LIMESTONE. "Millions on millions thus, from ago to age, With simplest skill and toil unweariable, No moment and no movement unimproved, Laid line on line, on terrace terrace spread, To swell the heightening, brightening, gradual mound, 13y marvellous structure climbing toward the day. Each wrought alone, yet altogether wrought Unconscious, not unworthy instruments, Uy which a hand invisible was rearing A new creation in the secret deep. Omnipotence wrought in them, with them, by them; Hence what Omnipotence nlonc could do, Worms did. ' Slime their material, but the tlime was turned To adamant by their petritic touch; Fiail were their frames, ephemeral their lives Their masonry imperishable. All Life's needful functions, food, exertion, rest, By nice economy of Providence Were ever ruled to carry on the work Which out of water brought forth solid rock." MONTGOMEUY'S Teli:an Island. AM elected as spokesman for a common and well-known mineral, which is abundant in every geological formation. Our age, there- fore, varies as greatly as it is possible for mundane time to allow. Chemically, our compost- 38 THE STORY OF A PIECE OF LIMESTONE. tion is always pretty much the same, being merely Carbonate of lime. In all the rock formations we are further dis- tinguished from the sandstones, shales, and con- glomerates, by our being almost wholly of vital origin, that is, formed through the agency of living beings; whereas the other rocks I have mentioned are the result of mechanical forces, wearing down and triturating pre-existing rocks, and then re- depositing the debris along old sea-bottoms. In consequence of this difference, the geologist finds in us by far the greater number of those organic remains, especially of marine animals, by whose aid he is enabled to sketch forth the development of the world's great life-plan. As a rule, all limestones have been deposited, as fine calcareous ooze, away out in deeper water ; consequently the circumstances have been doubly favourable for the preservation of any animals which might have died and become entombed in this limy mud. The more boisterous conditions which prevailed in the shallower waters, where coarse sands and con- glomerates were formed, prohibited such favourable preservation. At the same time, with the exception of what are known as freshwater limestones (which bear a vciy small pcr-centage to the other rocks of the earth's crust), I must acknowledge that the sandstones afford most valuable evidence of the terrestrial animals. This, as might be expected, is '/HE STORY 01,' A PIECE OF LIMESTONE. O ( J mainly owing to the fact that the latter were formed nearer to the shore so that carcasses of land animals accidently drowned or carried into the sea by rivers watering large islands or continents where they lived, would sink to the bottom, and be buried up in coast deposits ; whilst the sandstone and shale formations testify to the long-continued wear-and tear of the solid land by meteorological agencies. Therefore, the limestones bear out the idea of our planet's antiquity, by suggesting the immense lapse of time which must have occurred whilst simple and lowly animal functions were elaborating the greater proportion of all the limestone rocks. But I intend to let each of these speak for itself. They are of age, ask them ! Each contains its own suite of organic remains, the extinct creatures which lived and died whilst the limestone mass w r as slowly accumulating as calcareous ooze. They are tombs of the forgotten dead stony scrolls, written within and without. I myself belong to that most interesting geologi- cal formation known as the Silurian. Away in the heart of the " Black Country," where no less than thirty feet of solid coal abut against their flanks, you may see cropping up an irregular and continuous ridge of limestone hills. It is thence I am derived. You may gather some idea of the forces which slowly upheaved these strata by seeing the steep angle at which they lie : a little more and they would have been quite perpendicular. But this 40 THE STORY OF A PIECE OF LIMESTONE. upheaval was not violent or sudden; on the con- trary, I distinctly remember its operating through long - continued ages subsequent to the Silurian period. The process was so slow as to be almost imperceptible, for Nature knows scarcely anything THE STOKY OF A PIECE OF LIMTESTONE. 41 of those violent cataclysms which have been so foolishly ascribed to her ! Examine the steep flanks of the Wren's Nest, near Dudley. There is hardly a space of a pin's point which is not occupied by the remains of some creature in which the breath of life was enjoyed countless millions of years ago ! You strike the solid rock with your hammer, and immediately the percussion liberates a peculiar Kerosene odour, which tells of the old animal oils in which the limestone is steeped. The very hardness of these rocks is more or less indebted to the same organic cause. I am told that when sculptors, now-a-days, wish to harden their plaster- of'-Paris casts, they do so by boiling them in oil. The principle is the same with most limestone rocks of every age. They are steeped, saturated in animal oils ; nay, in many places across the Atlantic, where these old Silurian limestones and shales lie so deep down as to be within the action of the earth's internal heat, these oils have been distilled out of the rocks, and have followed the ordinary habits of fluids. It is by sinking through the over- lying masses that these oil-springs arc reached, and the valued liquor comes bubbling to the surface. Well does it deserve its common name of Petroleum " rock-oil." But few people imagine, when its brilliant light is illuminating their comfortable homes, that they are indebted to distilled Trilobitef for the luxury ! Here is another form of that grand ]aw of correlation of 42 THE STORY OF A PIECE OF LIMESTONE. physical force. The ancient Silurian sunlight fur- nished the means of vitality to the creatures which then enjoyed life. It was stored up in their tissues, and given forth in their buoyant gambols and locomo- tive powers. And when they died, what remained in their diminutive bodies decomposed, passed into other chemical forms, was preserved until our own day when men unlock this ancient sunlight from its oleaginous condition, and turn it to direct heat- ing and lighting account ! Fancy sunlight bottled up in the form of trilobites and mollusca ! No wonder these should present such stony and petrified appearances, when all the animal oils have been so completely drained out of them. How long these Wenlock limestones (for that is the name by which this section of the Silurian for- mation is known), how long, I say, it is since these limestones were upheaved and exposed to the action of the weather, I cannot say. Their hardness, as I have already mentioned, is most intense; but the wear-and-tear of the atmosphere has been such as to cause the fossils to stand out in relief; and a strange sight, therefore, is the exposed surface of the limestone slabs. The eye is bewildered by the number and variety of organic remains, each stand- ing forth from the fine limy mud in which it was originally enclosed. Little or no vegetation grows on this bare limestone surface ; the latter is too impenetrable to yield a foothold ; and so the geolo- gist has it all to himself. Heads and tails of Trilo- THE STOIIY 01' A PIECE OF LIMESTONE. 43 bite*, so plentifully dispersed that they immediately stamp the Silurian age of the rock, lie commingled with brachiopodous shells, worm-tubes, sea-mats, chain-corals, and encrinite stems. You require no prompter to remind you of the exuberance of animal marine life in this distant epoch ; and yet the Silu- rian period immediately succeeds the Cambrian, about which my distant relative, the Piece of Slate, gave you an account some time ago. Whilst the limy mud which subsequently be- came hardened into solid rock, and was upheaved into its present condition was being slowly formed in deeper water nearer to the shore there were deposits of a different nature going on. These con- sisted of muds poured into the sea by rivers, or wasted by tidal and current action from old coast- lines ; gradually, therefore, the limy deposits passed into the muddy ones, so that the line of junction was almost imperceptible. Occasionally the fine mud was carried further seawards than usual, and then a thin layer of argillaceous matter was thrown down over the limy material. This accounts for the frequent alternations of limestone bands and argil- laceous shales which you have doubtless seen in every section of Silurian strata. At various epochs during the immensely long period which elapsed whilst these beds were form- ing, alterations of the sea-bottom took place; the area where limy deposits had been forming became shallow, so that clay or mud began to accumulate 44 THE STOllY OF A PIECE OF LIMESTONE. over the same spot; or, the sea-bottom became deeper, and, in that case, calcareous or limy material slowly formed where mud had previously been accumulating. Occasionally, perhaps, the sea became so shallow that shingle-beds were strewn over the area where both lime and mud had been collecting. My hearers can readily understand operations like these. They are still going on over various parts of the earth's surface ; but the time of observation has not been extensive enough to see what they can effect. Only that simple element of time is required and our planet is changed as by the will of some powerful magician ! And, for my own part, I do not see why the timid, unconceding spiiits of modern times should begrudge time to the geologist, any more than they do distance to the astronomer ! The various strata which vertically succeed each other in the Silurian formation plainly indicate the geographical changes which affected these ancient seas ; and, at the same time, imply the vast lapse of time during which they were brought about. Suffice it to say, this Silurian formation, with its enclosed strata, attains a total thickness of no less than twenty-six thousand feet ! Leaving my junior brethren to speak for them- selves when their turn comes, let me try and re- member some of the physical circumstances which marked the epoch of my own birth. First of all, what a different geography marked the surface of the globe then from what there is at present ! I THE STORY OF A PIECE OF LIMESTONE. 45 believe there was a much wider extension of sea than there is even now, when it extends over more than two-thirds of the earth's surface ; and, owing to there having been fewer disturbances at that time, the sea was more equable in depth ; whilst, at the same time, the dry land was less distinguished by mountain-chains. In consequence of the equable depth (or nearly so) of the sea, and of the similar climature which most parts of our world seemed to have enjoyed alike, there was less difference in the animals and plants of various geographical zones ; but this principle was in existence, although nothing like so broadly developed as at present. The Silurian strata of America, Australia, Asia, and Europe differ very little in their general fades of organic remains. You have no difficulty in recognizing the old features which struck you when examining the Dudley strata; but when more minutely studied, the naturalist makes out certain " colo- nies," caused doubtless by difference of geographical circumstances. As Lingula Leuisii. the time passed away during which the great sequence of beds belonging to the Silurian formation were being elaborated, other changes took place in organic life. The most marked feature was that of a progression from lower to higher types. Species multiplied, and the general total of life- forms became more varied and less cosmopolitan. 40 THE STCfaY OP A PIECE OF LIMESTONE. The lo\vest beds of my parent formation go by the name of Llandeilo Flags, so named from the locality in North Wales where the typical section may be studied. They are, as their name implies, strata of flaggy sandstone, much worked for com- mercial purposes. There is a considerable quantity of limy matter in their composition, and this gives them a peculiar indurability. Interstratified with the beds of this deposit are immense layers of ancient volcanic matter, basalts or tuffs: these Fig. 8, Basaltic rock inters (.ratified with aqueous rocks ; b Basaltic dyke. flowed over the old sea-bottoms, when ejected from submarine volcanoes, or volcanoes situated near to the coast, as we find they usually are now-a-days. The ashes or tuff's were carried by the winds, and the ancient seas had their surfaces thickly strewn with cinders for hundreds of miles; these sank to the bottom, and alternated with the regular shore deposits. Succeeding the Llandeilo Flags, we have another division, known as the Bala Lirue^ THE STORY OF A PIECE OF LIMESTONE. 47 stone, also named from a locality : it has inter- stratified with it beds of sandstone, slates, and volcanic rocks again, which were doubtless strewn over the old sea-bottoms just like those already mentioned. The Caradoc Sandstones, named from their locality in Shropshire, containing also shelly sandstones, with soft shales and conglomerates, lie above the Bala Limestone, and complete what geolo- gists have termed the " Lower Silurian Rocks." They differ, as a whole, in Great Britain, from their comprising such a huge bulk of strata of igneous or volcanic origin. In some places these are actually thicker than the rocks of sedimentary origin. What a stormy, restless epoch was that ! The old sea- bottom was subjected to shocks and volcanic over- flow more intense than those in the neighbourhood of Ijtland, where the Skaptar-jokul is quivering with suppressed rage and superfluous power ! Then, again, these Lower Silurian rocks have neither so abundant, nor so highly organized a fauna as the rocks of later date. Let me mention the next in order, before I give you my personal recollections of the extinct creatures you find imbedded in these rocks as fossils. The Ordovician strata commence with the Llandovery slates (another localism) ; after which you have the May Hill sandstones (about which not a few geo- logists quarrelled some years ago) and the Tarannou shales ; altogether, this series is about two thousand feet in thickness, the Lower Silurian beds i havo THE STORY OF A PIECE OF LIMESTONE. described being upwards of nineteen thousand foot thick. Next come the uppermost beds (to which I personally belong), known as the " Upper Silurians/'' and which attain a total vertical thickness of nearly five thousand feet. They include several deposits of minor importance; such as the Woolhope beds and the Wenlock limestones and shales, completing what is known as the " Wenlock Group." Then succeed the Ludlow beds, the Aymestry limestones, and the Downton sandstones (in the latter of which is found a bed composed of scarcely anything elso than the bones, teeth, and scales of small fishes, belonging to the placoid and ganoid orders). It is in these soft shales you find the fossils so well pre- served. The shells, although they have been extinct for unknown millions of years, still retain their beautiful iridescent nacre, which, how- ever, soon decomposes by atmospherical influence. So much for the " strati- graphy " of this most inter- esting geological formation ! At the forms of life which swarmed the seas of this distant epoch I cannot do Fig. 9. Curved Orthoceras ' (.'yrtoceras Murchlsoni). more than merely glance. I have mentioned that, gene- rally speaking, there was a progression. This is THE STORY OF A PIECE OF LIMESTONE. 49 true only of the advance in the main, for, during the earlier portions of the Silurian period, huge rtliocemtites abounded, and these are among the highest classes of the mollusca. The muddy sea-bottoms swarmed with "sea-pens," now known as Graptolites, allied to the little lg ' ^ Corallines so plentiful in mo- dern seas. The chief difference between them being that the former were free and unat- tached, whereas the latter always adhere to some other body. But, of all forms of life, those of the Trilobite family were most abundant. Several hundred speoies are known to belong to the Silurian forma- tion alone. They were crusta- ceans, allied to the King Crab* of the Moluccas, and at that time represented the lobsters and crabs of the present day. This is a group which has Orthoceras, up- always been noted for its aber- . part rant types. Like other Crustacea, the showing per- J l forateiicham- Trilobites underwent metamorphoses or ber - larval changes. So well do the old * The larva or young of the King Crab very much resemble* of the ancient Trilobites. E DU THE STOliY OF A PIECE OF LIMESTONE, rocks tell their story of ancient life, that tha geologist has traced the metamorphoses of Trilo- bites through twenty developmental stages, from the egg to the adult animal. In the last condition its body was enclosed in tri-lobed joints, which served as a defence, and at the same time were flexible enough to be adjusted to all the motions of their possessor. In fact, they served all the purposes Fig. 12. Various species of Graptolitcs, from the Silurian rocks. of an ancient coat of mail. These various species of Trilobites literally swarmed in every sea of the Silurian period. There were species alike peculiar to deep water and to shallow, and the rocks formed under these different conditions (as I have above related) indicate which these species were. Well do I remember them crawling over the oozy sea-- bottom, gorging the mud, as I am told earthwoi nig THE STORY OF A PIECE OF LIMESTONE. 51 Fig. 13. now do, for the sake of the animalcnlar matter dispersed through it. Not long ago, some of these fossils were found which are now known to have the legs attached to the under side. As a rule, however, the Trilobites are usually met with with- out these useful appendages, and some discussion formerly arose whether they had them or not a discussion which is now set at rest. "When any danger approached, they coiled themselves up like modern woodlice, and, in this state, you may not unfrequently find them fossilized. When the adult animal moulted, it did so at the junction of the head and carapace; and this accounts for the myriads of detached heads and tails found in every piece of Silurian limestone Spiny Tribute (Acid^r-: s i>nfre- or shale. The Trilobite had compound eyes, arranged sessile, on half-round prominences, on which they were set like so many mounted jewels. Some species had not less than four hundred of these distinct eye- facets. Thus we find the structure of this little creature completely setting all those wild theories no.,,). Sllurit.. rocks of Bo- hemia. 52 THE STORY OF A PIECE OF LIMESTONE. at defiance in winch some people have indulged. Their eyes indicate a similar constitution of the atmosphere then to what it is now, for the passage and refraction of the rays of light. And this fact is supplemented by the sun-cracks, rain-drops, &c. f which pit the sandstones, telling of meteorological action identical in its operation with the present. Indeed, all the facts go to prove that even at this distant epoch of the world's history, the light of the sun and the atmo- sphere of the earth were very like what they are at the present time. , During the period of the " Middle Silurian " there w r as a great change in physical geography. How long a time had elapsed since the Lower Si- lurian strata had been formed, with _, .. . their enclosed great sheets of volcanic Tnlobite from the Silurian rocks, lava and ash, may be guessed at from Pukowa, Russia the fact that the May Hill conglome- (Ttatw mwrf. t are com d f th wagte f candu). * ments of the former ; they had there- fore been solidified into such rock as you now see them, and been uplifted from the sea-bottom into coast sections; and it was from their wear-and-tear, when in the latter condition, that the May Hill conglomerates were formed. Thus does the very structure of many of these deposits indicate the immense amount of time which elapsed during their elaboration. It was during the deposition of the THE STOllY OF A PIECE OF LIMESTONE. 53 " Upper Silurian " beds, however, that life was most prolific was most varied. The sea was aglow with huge coral reefs, around which swarmed sea-lilies, star-fish, inollusca of innumerable species, nautili, orthocerata (of whimsical and various shapes), and trilohites. The scene was very busy and most animated ; the compound corals shone in various colours, and the adjacent sea-bottom was literally a submarine forest of crinoids, or sea-lilies. How abundant these lovely creatures were you may guess from the fact that you Fig< 15< can scarcely pick up a fragment of Upper Silu- rian limestone without perceiving some of their detached ossicles, or joint- ed plates. In and out of these waving forests, with the arms of the animals representing Pentnmerua Kmghtii. branches, the innumerable species of trilobites swam, and crawled, and climbed. Every now and then some brightly-colo/ired pecien flitted past like a butterfly. Univalves (Murcliisonia and Euompha- ?tt.s) of delicate ornation and colour, slowly dragged their pretty shells about ; the Cystideans, with their dwarfed stalks, but highly-ornamented and sculp- tured heads, dotted the sea-bottom. Over all, the occasional long arms of star-fish wound and un- wound \ delicately beautiful nautili, of various species, 51 THE STOHY OF A PIECE OF LIMESTONE. Fig 1<3. sometimes crawled, sometimes filled their air-tubes, and mounted to the surface of the water. The whole of Wenlock Edge, in Shropshire, is nothing more than an ancient Silurian coral reef, around which, millions of years ago, all the vital circum- stances I have been attempting to describe took place ! Of all these beautiful coral forms none were so lovely as the " Chain-coral " (Ilalysites catenulatm). Well does it deserve its name, for even now it appears like some watch-chain of exquisite work- manship interfolded in the solid rock ! The largest of these corals was the Favosites polij- morpJia. Amidst all should not be forgotten the nests, groups, or even banks of Terebratula, Atrypa, Rhynchonella, Spirifera, Producta, Strophomena, and Pen- tamerus ; all of them belonging to the lowest class of Mollusca, then in luxuriant abundance, but now waning into extinction. Towards the close of the Upper Silurian period, Vertebrata, in the form of fishes, made their appearance : at first they were few in number and small in size : but ere long they multiplied amazingly. They had their old feeding and breeding grounds, and along this part of the old sea-bottom their remains were of course most thickly accumulated. Such is the explanation of the Chain- coral. THE STORY OF A PIECE OF LIMESTONE. PALEOZOIC BRACIIIOPODS. 1. Lingula Lewisii (Silurian). 2. Obolus Apollinis (Silurian). 3. Leptaena transversalis (Silurian). 4. Orthis elegantula (Silurian). 5. Orthis striatula (Devonian). 6. Stropho- mena depressa (Silurian). 7. Atrypa reticularis (Silurian). 8. Pen- tanicrus. 9. Spirifer striatus (Garb. Limestone). 10. Spirifer spe- niobus (Devon). 11. Spirifer trigonalis (Carb. Limestone). THE STOllY OF A PIECE OF LIMESTONE. 57 Lucllow bone-bed to which I have already alluded. I am told that off the western coast of Ireland, near Kockall, such a bone-bed is now actually in course of formation ; so that if it becomes covered over by succeeding deposits, it may one day present a similar appearance. Of the land plants of the Silurian period I cannot say much ; but that the dry land was more or less clad with green I have not the slightest doubt. What makes me feel so confident about this is that the small spores of club-mosses are to be found fossilized in the " bone-bed " I have mentioned. You can only see them with the microscope, but there is no doubt as to what they really are. These spores must have been carried by the land-breezes seawards, and strewn over the surface of the ocean until they sank, and were buried in the deposits accumulating along the bottom, where the bony- scaled and shagreen-skinned little fishes were living, breeding, and dying. My own story is finished, for the formation of cracks and fissures in our solid rocks belongs to a later time. Of the minerals and metals which were segregated along the walls of these fissures until the latter became " metal lodes," I cannot say ; but thus much that, apart from the numerous fossils contained in us, our rocks will always be esteemed interesting to man, seeing that it is in them that the over-valued metal gold is usually found most abundant, all the world over ! 58 THE STORY OF A PIECE OF SANDSTONE. CHAPTEK V. THE STORY OF A PIECE OF SANDSTONE. " You may trace him oft By scars which his activity has left Besides our roads -and path-ways (though, thank heaven, This covert nook reports not of his hand), He who with pocket-hammer smites the edge Of every luckless rock or stone that stands Before his sight by weather stains disguised, Or crusted o'er with vegetation thin, Nature's first growth, detaching by the stroke A chip or splinter to resolve his doubts; And with 1hat ready answer satisfied, Doth to the substance give some barbarous name, Then hurries on ; or from the fragment, picks His specimen." WORDSWORTH'S Excursion. IKE my mineralogical acquaintance, the piece of limestone, I am deputed to do duty for a group of individuals common to every geological formation. But each of us has a separate story to tell, and I shall find it quite sufficient to bring all the circumstances of the epoch in which I lived sufficiently clear to my own recollection. It is declared that a few singular people who live in the present period (so far removed in time from mine) profess to be THE STORY OF A PIECE OP SANDSTONE. 59 able to interrogate a piece of limestone or sand- stone, by what they term Psycliometry, and to get its story in some easier way than by the ordinary cross-questioning of science ! All I can say is, I wish the events of my own life were so permeated in my substance. If this theory be true, the modern science of geology w T ill have to give up induction, and fling itself into the arms of the spirit- rappers ! Every one of my listeners knows what a piece of sandstone is like. There is no need for me to de- scribe my appearance, therefore, as novelists do their heroes. But how many thus familiar are aware that in ninety-nine cases out of a hundred every such piece of sandstone was originally formed along the floor of ancient sea-beds ? Those ocean bottoms are now represented by dry land surfaces, where the vegetation luxuriates on the mineral substances accu- mulated under such widely different circumstances. Even where no marine organic remains are present, as fossils, to prove the marine origin of the sand- stones, that origin is none the less certain. I can- not speak with certainty as to the nature and ex- tent of the dry lands and continents of the epoch in which I was born. Suffice it to say, they must have been great, for the rivers which watered them were large, and brought great quantities of mud and sand down to the sea. The ocean currents and tides also wore away the coast-line, and added to the quantity of loose sand and mud which accumulated 00 THE STOltY OF A PIECE OF SANDSTONE. Fig. 18. under the waves in consequence. Thus it was that I was born. My earliest remembrances are of my lying loose and unconsolidated on a great sea-floor; and of constant additions being made to the sheet of which I formed part. It was whilst I was lying in this state, as so much ordinary sand, that I received my impressions of what was going on around me. These consisted of a familiarity with the commoner animals which lived in the sea, or with occasional plants and vegetables which had been carried there by rivers, until they sank to rest in my bosom when they had arrived at a water-logged condition. Of these I will speak presently. Meantime let me make a few remarks as to the changes which transposed me from loose marine sand into hard sandstone ; and in doing so, it will be evident that the same explanations will answer for the similar alteration of sandstone rocks, both of earlier and later geological periods. The sand or mud brought down and laid on the sea-floor in the manner I have mentioned was not of an absolutely pure character as regards its mi- neral composition, that is to say, it was not all silica, or alumina, as the case might be. In most Calceola sandal ina. THE STORY OF A PIECE OF SANDSTONE. 61 instances the material was mixed with more or less of iron rust, or of lime, and silica. The three latter acted as cementing pastes to those sandstone rocks which are now of a lightish colour; and the iron was the compacting agent with such dark red rocks as that of which I form part. Indeed, in most cases, even when the sandstone is of a light yellow, a small percentage of iron has gone a great way towards binding the loose grains of sand together, and thus producing a hard rock. When this chemi- cal agent has been equally dispersed through the sandy mass, you have the thick-bedded sandstone, or " free -stone." When it was intermittent in its action, or unduly mixed up, or occasionally alternated with something else, then the sandstone becomes " flag-stones " of greater or less thickness. Sometimes you will see a mass of red sandstone more or less mottled. This has been caused, in most instances, by patches of vegetable matter- ancient fucoids or something of that sort, which decomposed, and whose chemical changes combined with the iron, and locally prevented its colouring effect. Of course it will be evident that our hardness or softness greatly depends on the percentage of cementing material, or to the different circum- stances under which we were formed. I have nc doubt that, when the chemical changes above men- tioned were going on through an immense thickness of accumulated sand, the hardening process was 62 THE STORY OF A PIECE OF SANDSTONE. greatly assisted by the pressure of the overlying volume of sea-water. The epoch to which I belong is sometimes called the " Old Red Sandstone," and, occasionally, the "Devonian." The former term is given to our formation to distinguish us from the " New Bed Sandstone," overlying the coal-measures ; whilst the latter name is of local origin, and indicates that the system is largely developed in the lovely county of jfc Fig. 19. Clymcnia. Devon. Indeed, that sunny land owes no little of its physical attractions to the various mineralogical structure of the rocks of our formation. Perhaps I can boast of the fact that there are few other formations which have such a world-wide extent as that to which I belong. In the United States it stretches over an area nearly as large as Europe, there being one continuous coral reef included in THE STORY OF A PIECE OF SANDSTONE. 63 it which covers an area of nearly half a million of square miles. In Canada there is also a great ex- tension of this formation ; whilst in South Africa its area is greater still. In Russia one sub-division is much greater than the whole of England, and there is a large extension of beds of similar age in Asia Minor, as well as in Australia. The original name of " Old Red Sandstone," given to the formation of which I am a humble part, was conferred upon the thick beds found developed in Herefordshire, Worcestershire, Shrop- shire, and South Wales, as well as others supposed to be of similar age in Scotland. In the former localities they attain their greatest thickness, which is between eight and ten thousand feet. There, geologists have divided the series into four divisions, of which the lowest may be said to blend with the underlying Silurian formation, and the uppermost with the succeeding Carboniferous. In Scotland the beds are not so thick ; their greatest vertical accumulation amounting to about four thousand feet. It would seem, therefore, as if the material which formed these rocks came from tne south-west, thinning out in a north-easterly direction. In Devonshire, as well as in Ireland, there are two series of strata included in the same formation, which seem to have had quite a different origin. The former indicate seas, in which coral reefs abounded, and the latter tells us plainly of a large continent which existed towards the end of this Cl THE STORY OF A PIECE OF SANDSTONE. epoch, on which there were freshwater lakes as ex- ' tensive as those of North America. Perhaps it was the same continent whose rivers contributed no little of the sand and mud which, when strewn on the sea- bottom, formed the sandstones of which I am part. I am told, however, that there are some geologists who show that all these red rocks are of fresh- water, and not marine, origin; and that they have even mapped out the sites of the lakes where they were formed . How shall I tell of the strange sights which I beheld when quietly lying on the ocean-floor ! The sea-water had the same specific gravity it has now, and the constitution of the atmosphere was similarly formed. It is perhaps more than probabLi that there was mixed a large percentage of car- bonic acid in the air before the Carboniferous epoch, and that this was absorbed by the plants, and the atmosphere cleared and rendered fit for animal life at the same time. The theory is ingenious, and has of late years been growing into considera- tion among geologists. Occasionally the sea-water became turbid and red, owing to larger quantities than usual of the refuse of igneous and metamor- phic rocks being carried down by the rivers. As is well known, these contain large quantities of iron, which are easily decomposed, and enter into new combinations as oxides ; whence my colour and also my cementing agent. The sea-bottom was covered with groves of fuci, or sea-weeds, in which a large THE STORY OF A FIECE OF SANDSTONE. 65 crustacean, bearing some resemblance in its huge claws to the modern lobster, lived and left its spawn. The latter is actually found fossilized in our sandstones, and bears some resemblance to a flattened blackberry. Among geologists, I am told, Fig. 20. Huge fossil Crustacean (Tterygotus Anglicus). Old Red Sandstone, Forfarshire. it goes by the name of Parkia, whilst the huge lobster which left it, and which was at least six or seven feet long, rejoices in the name of Pteryyotus. Several species of this common form are met with in Scotland, as well as in England. Another large 66 THE STORY OF A PIECE OF SANDSTONE. crustacean, which appeared during later Silurian times^and was nearly related to the Pterygotus, now g goes by the name of Eurypterus, on | account of the breadth of its swim- | ming feet. '8 But by far the commonest creatures < which enjoyed life in the sea of my I birth were the fishes. Indeed, my ^ epoch has been justly called " the gi age of fish." In many places they 5 swarmed in shoals. Most of them I belonged to an order of which there .g are very few now living, termed the * Ganoid, on account of their being 1 covered with a series of oval or .5? H^SST ^ r homboidal bony plates, instead of g" scales. These bony plates had an % exterior varnish ; whence their name. At present, I am told, there are ~ several species living in the rivers of | North Africa, and others enjoying life in the lakes and rivers of North | America. But out of nine thousand '1 species of fish known to naturalists 6 the Ganoid species only number g about twenty-nine. Indeed, the wide geographical areas where the two outliers of this once numerous and H world-wide family of fishes are now lingering, indicate their antiquity, and suggest how THE STORY OF A PIECE OF SANDSTONE. 67 many geological phenomena have taken place to bring about their present geographical isolation. By many it is supposed that the whole of this family would now have been extinct, had it not been for their withdrawing from the keen battle of life that subsequently went on in the seas by the introduc- tion of other species, and so confined themselves to fresh-water condition. Few of these peculiar species Ptcrichthys Millcri. have a bony skeleton properly hardened, as is the case with ordinary thin-scaled fish. No doubt the strong, bony integument did duty instead. Indeed, among the fish which lived during my lifetime, scarcely any possessed a solid skeleton. The largest of these strange-looking fish is now called Astcrolcpis from the star-like markings on each of the scales. It reached the entire length of between twenty and 68 THE STOHY OF A PIECE OF SANDSTONE. thirty feet. Other common forms were the Holop- tychius, noted for its large oval scales being pecu- liarly wrinkled ; the Pterichthys, or " winged fish," so called on account of its two pectoral fins, which are very large and resemble paddles, being placed Fig. 23. near the head, where they look like wing appendages. The plates which covered this fish were very large, and orna- mented by a series of granules. The former of these two species lived in what is now America, Russia, and England, and Scot- land. Then came the Ccphalaspis, or " buckler-headed " fish, so called because its queer-shaped head was encased in a shiny bony buckler, in form not un- like a cheesemonger's knife. Its trilobed body was covered with lozenge-shaped bony plates. The Ostcolcpis, or " bony-plated " fish, was the most abundant ; its name being FteTichthys cornutus -\ i f j_i L ~\ derived irom the minute rnom- boidal plates which covered its body, and protected it, like the links of an ancient coat-of-mail. Besides the fishes of this class, which, singularly enough, were farther distinguished by their having the THE STOBt OF A PIECE OF SANDSTONE. 69 tail unequally lobed and not regularly cleft as in the common herring and other scaled fishes there were associated with them others, having an affinity with species of the Shark family. These are called placoid fishes, on account of the skin being a kind of shagreen, dotted with minute plates or points of hard bony matter. They also have a cartilaginous skeleton, as, for instance, the common skate, sturgeon, &c. Well do I remember the above fish, ranging in size from the Astcrolcpis to the little Onchiis and Osteolepis, of only a few inches in length ! The quick, active movements of the latter fishes, as they roamed in and out of the thickets of seaweeds, caused the light to flash from their enamelled scales, and sometimes only too surely pointed out their playgrounds to their cestraciont enemies. They had their feeding and their spawning-grounds, and each of these places is now represented by the greater number of fish found fossilized in the flagstones, as in the Caithness flags, and the yellow sandstones of Dura Den. Sometimes, also, great numbers were killed by unusual quantities of mud being poured into the water and choking them, as a turbid river will, at the present time, suffocate the smaller of its tribes. How suddenly these died is indicated by the fact that thousands of fossil specimens are to be seen with their fins erect, like those of the perch when he is " struck by the angler." Others are contorted and bent, as if in pain ; their last dying struggles having 70 THE STORY OF A PIECE OF SANDSTONE. thus been faithfully handed down by the stony records in which they were imbedded. Some few of the fossil fish of this period had reptilian characters in their teeth, &c., indicating and linking on, as it were, the next great family which should rule creation. Wherever the Old Red Sandstone has been met with, some, if not all, of these peculiar ganoid fishes have been found fossilized., Therefore they are good indications of the geological age of any such formation. I will not trouble my listeners with the dry, tcahnical details of how the strata succeed each other in my parent formation. I want, if possible, briefly but vigorously to sketch the life-character- istics of that distant epoch. I have thus far devoted myself to the fossil fishes because of their abundance, and also of their very striking peculiarities. I now come to other crea- tures, perhaps not less abundant, but not so at- tractive. I must premise, however, that such marine creatures as corals, mollusca, and trilobites were not very abundant over the area where I first saw the light. They delighted in clearer water, and so are to be found over the area where that existed. Indeed, generally speaking, those parts of the sea- bottom where most of the red muddy matter was poured in were shunned by all forms of life, not excluding the hardier fishes. . Hence it is you rarely find in the very red sandstones any organic re- mains or fossils beyond a few vegetable impressions. THE STORY OF A PIECE OF SANDSTONE. 71 Fig. 24. Of course there were various parts of the same sea thus distinguished by different physical circum- stances, and life was developed, or located accord- ingly. Let me, therefore, give you some slight account of the area where " blue water " was most in force, and where, in consequence, there were the most numerous assemblages of Crustacea, shell-fish, and corals. The localities in Great Britain where these peculiar fossils are found in strata of the age I am describing, lie chiefly in South Devonshire, as well as along the North Devon coast. At the latter place you may see beds of sandstone, red and yellow, alternating with slates, limestone bands, &c., the last-mentioned being es- pecially full of organic re- mains. The total number of species of fossils of all kinds which have been found in Devon alone three hundred and eighty- three. The highest of the series go by the name of the " Pilton Group," and these are perhaps of the same geological age as the Devonian strata in Ireland. Among the fossil shells which lived during this epoch, and which occur at the above-mentioned places in the fossil state, the most numerous were those belonging to the Bracliiopoda. Indeed, these Fossil Coral (Stauria astrce- formis). IS 72 THE STOBY OF A PIECE OF SANDSTONE. shells far out-numbered the ordinary and more highly-organized conchifera, whereas at the present time the latter are hy far in the majority. Among the commonest of the shells I remember were several species of Spirifer, Stringocephalus, &c., and also of Clymenia, Megalodon, and others. The last was a lamelli-branchiate mollusc, allied to the oyster and mussel of the present day. Among the corals there abounded in Devonshire the Favosites Fig ^ polymorpha, or "many-shaped" coral, as well as Heliolites, or " sun-coral," Strorribodes, &c. The latter my readers will readily recognise when I tell them it is the common pink or red variety usually bought at Torquay, and which, when polished in the mass for mantel- pieces, has such an attractive appearance. All of them are Zaphrentis cornicula. ,. , ., ,. , portions of reef-building corals, and well do I remember the animated appearance of the clear water when the " reefs " flourished in their bright colours, and trilobites, fish, and crustaceans swarmed around the busy pile. The Trilobites found in the Devonian limestones are of a peculiar type, equally distinct from those of the preceding Silurian period, or of the succeeding Carboniferous. Among the commonest of the genera were Brontes, noted for its fan-like tail, and Homalonotiis, equally distin- THE STORY OF A PIECE OF SANDSTONE. 73 guished by the double row of small spines running down the central lobe, and which give to it a more Fig. 26. Common Devonian Coral (Favosites polymorpha). Fig. 27 Cyathophyllum liexagonum* " trilobed " appearance than any other species in the 74 THE STORY OP A PIECE OF SANDSTONE. wliole family. But, clear though the sea-water generally was in which these Devonian beds were formed, every now and then shifting currents brought fine mud and other sediments. These were thrown down on the ocean-floor, where they alternated with the bands of limestone. Eventually the sea again maintained its purity for a long period, during which the corals and other clear-water-loving animals resumed their avocations, and left behind them traces of their work. I have said that where Ireland now stands, was part of a great continent, or some other extension of dry land, towards the close of the age in which I was born. Of this I cannot speak with certainty ; but the evidence is strongly in favour of the idea. In the country of Kilkenny are a series of fine- grained greenish sandstones, regularly bedded ; they are full of evidences of fresh- water deposition. Nowhere, in Europe at least, will you meet with such well-preserved land-plants ; all of which prove, by the perfect manner in which they have been pre- served, that they could not have been drifted from a distance, or been in the water long. Among the most attractive of these remains are those of a tree- fern, formerly called Cyclopteris, or "Bound-leaved Fern," but now named Palceopteris Hibernians, or the "Primitive Irish Fern." Nothing could be more exquisite than this beautiful fern, even in a fossil state, and you may therefore guess how attractive were its groves when it was the monarch .THE STORY OF A PIECE OF SANDSTONE. '75 of tlic primeval forests, and its graceful fronds bent over the clear waters of a lake which equalled in picturesqueness those of the Emerald Island of these times. This fern is not unlike, in general appearance, the modern " Koyal Fern " (Osmunda rcgalis), with the exception that it has no mid-rib its veins ramify- ing from the base towards the exterior of the leaf. Associated with this tree-fern were great and small club-mosses, which trailed over the ground, and formed a rich green carpet of various tints. Among the commoner of these extinct club-mosses were Sagenaria (of which the seed-vessels and catkins are well preserved) ; Psilophyton, a simpler club- moss, and the larger and more tree-like Lepido- dendron, which afterwards became so abundant during the Carboniferous epoch. Besides these we have evidences of other kinds of vegetation, and there is no doubt that the higher grounds were more or less covered with more highly- developed and organized species. What is further corroborative of the fresh-water origin of the Irish sandstones is the immense number of bivalve shells, exactly resembling the large fresh-water mussels (Anodoii) whicJi abound in modern English rivers. Both in appearance and structure these fossil shells are evidently closely allied, and therefore they are called Anodonta. They abound by thousands in some parts of the sandstones, associated with plant- remains, and with those of crustaceans which seem 76 THE STOHY OP A PIECE OP SANDSTONE. allied to the modern crayfish. So long did these large Irish lakes exist, that mud was strewn along their bottoms which ultimately formed rock several hun- dred feet in thickness. I am told that similar de- posits of fine mud and shell marl are now going on along the floors of the forest-fringed lakes of North America. Change the character of the vegetation there, and you have no indistinct, restoration of the Irish Devonian lakes. Many of the fish would do ; for the " hony pike," a ganoid fish, still lives there, associated with colonies of " swan mussels " (Anodon) clustering on the bottom. So much for the brief outlines of my story. Much more could be said upon this remarkable epoch ; but if I have given anything like an idea of my origin and of the character of the life-forms with which I was brought into contact, my business is done, and I accordingly retire for another geological speaker. THE STOBY OF A PIECE OF COAL. 79 CHAPTER VI. THE STOKY OF A PIECE OF COAL. "A passion for plants had so grappled his soul, That an old Hortus siccus each spare moment stole ; For which he had ransacked the swamps and the meads, Till his Hortus was richest in grasses and reeds. But a strange antiquarian whim he displayed ; From the simplest of plants his selection was made, And of structure primeval like none we descry 'Mid the bountiful gifts that the seasons supply; Nor confined he his search, for the earth widely knew, From the poles to the tropics the treasures he drew: Which long in his cabinet hoarded so slily, As an ancient Herbarium are prized very highly." King Cole's Levee. i AN any of my listeners form any idea of what a million of years means ? It is very difficult, I grant, but I cannot give any more definite conception of my own great age than by saying I am many millions of years old. Before I attained my majority that is to say, before I became really and positively coal I had existed in manifold forms. You cannot hit upon a greater mistake than to suppose I was origi- nally made just what you now see me a jetty mass of mineral. The doctrine of metempsychosis, said to be held by the Hindoos, would apply almost 80 THE STORY OF A PIECE OF COAIi. literally to my own biography. You may trace my career through a hundred different stages, each more widely various than the other. Nay, the process of elaboration through which I have passed is so complex that I may well he forgiven if I have not a clear recollection of it myself. I am English horn and bred, notwithstanding the seemingly tropical character of my antecedents. In some measure, it may be thought that I hardly partake of English characteristics as regards the climate which affected my earlier career ; but I can assure you I was never once removed from British ground. In the distant ages to which I have briefly referred, my recollections go back to waving forests of tree-ferns and gigantic club-mosses, as well as to a thick underwood of strange-looking plants. The name now given to this formation by geologists is termed the Carboniferous, and you may form some idea of the ages which have flowed away since then by the fact that no fewer than nine subsequent distinct formations and periods occurred. These are known as the Permian, Triassic, Liassic, Oolitic, Cretaceous (or chalk), Eocene, Miocene, Pliocene, and Pleistocene, to say nothing of the epoch com- prehending the human race. To make myself still more clearly understood, it is necessary to state that the formations newer than that to which I belong attain a vertical thickness of more than fifty thou- sand feet ! All this mass was slowly formed by gradual deposition along old sea-bottoms, &c., whilst liiE STOUT OF A PIECE OF COAL. $\ & mere than equivalent period of time was taken up in the upheaving and other processes which have elevated these rocks into their present position ! Fig. 29. Vertical section of.CalamUe, cut through node. The climate and geography of Great Britain were o 33 THE STOUY OF A PIECE OF COAL. very different from what they now are when I was born. You must imagine a soft balmy temperature, neither too hot nor too cold, and lacking those ex- tremes which at present characterize the seasons. There was no great necessity for extreme heat Branches, and fruit (l^epidostrobus} of LepidodeiiJicn* rather it was most important to the growth of a luxuriant vegetation to be free from cold. There were few ranges of hills or mountains, for these always cause a refrigeration of the atmosphere by condensing the clouds; thus hanging the sky with THE STORY OF A PIECE OF COAL. 82 a curtain which shuts off a great deal of solar heat. True, right across what is now central England, there stretched a mountainous barrier, perhaps of old Fig. 31. Transverse scctiou-of Calamite, showing cortical layer surrounding wooily wedges. Silurian rocks. Scotland and Wales -were also then widely different from what these countries are at present. Instead of the grand mountainous 84: THE STORY OF A PIECE OF COAL. scenery they now possess, there were long-extended saline mud-flats, thickly studded with trees now extinct, and known to the geologist by the names of Sigillarias, Lepidodendra, and Calamites. In fact, all the district now considered as " coal-yielding " was then similarly circumstanced. The entire area had a geographical condition similar to the marine swamps which now fringe the coast-line of the Southern States of America. To these the slowly ebbing and flowing tides had access nearly twice a day. Around the more aged trunks of these extinct trees, standing on a muddy, shallow sea-bottom, so to speak marine worms clustered, and their coiled tubes are now occasionally found fossilized, along with the petrified vegetation to which they clung when in life. These Spirorbi, as they are commonly termed, are tolerably plentiful in the north of England. It was owing to the semi-aquatic, semi- terrestrial character of the area on which the luxu- riant vegetation of the Carboniferous period grew, that we now find so many fossil mussels and other marine shells imbedded in the same strata. I am told that chemists have discovered only one part of carbonic acid associated with ten thousand of the other gases forming the atmos- phere. The atmosphere of the period when I was born possibly contained more. This larger quantity was absorbed by the waving forests into their structure, and the carbon added to their solid bulk. Day by day, and year by year, each individual tree THE STORY OF A PIECE OF COAL. 85 grew, so that the mass of solidified carbon increased, but without exhausting the original store. This was constantly being furnished by volcanoes, as well as by the lowly animals of my own time. Every- thing, they say, is composed of minute parts, and originally my atoms freely floated in the air in the condition of carbonic acid. This was before I had entered into that cornbina- tion which made me part and parcel of a living tree. Once having been sucked into the leaf-pores of a Lepidodendron or tiigillaria, I started existence under a new form. I became subject to those unknown laws of vital force which philosophers find so great a difficulty in ex- plaining. I had now an active duty to perform, and had to assist in the growth and well- being of the tree in whose bulk I lay. But this did not prevent B.u-k of Sigillaria Grco- me from noticing the many strange objects which surrounded me. Tree lizards, not very much larger than those which now haunt the sunny banks of old England, climbed up and down the sculptured branches of the forest trees, and lived upon the marsh flies and beetles, whose "drowsy hum " was the only sound that broke upon the still- ness of the primeval woods. They found a shelter in 86 THE STORY OF A PIECE OF COAL. the hollow trunks otSigfilarise, in association with the pupae of beetles and other insects. In some places they have been found fossilized together, a con- served recollection of those bygone times. Great reptiles, resembling frogs, in some respects, belong- ing to an order called Labyrint/iodonta, abounded in many parts of Ireland and Scotland. In the former country was a genus called Opliidtrpeton, which had a snake-like form, and a compressed tail, so that it very much resembled a water-serpent. No fewer than five different kinds of amphibious creatures then lived in the very country which now boasts of its freedom from these creatures ! It is singular to notice how a great many of the fishes of this period had reptilian characters, whilst the first -introduced amphibians were no't only the most lowly organized, but in many respects were related to fishes. Very frequently the salt-water reaches were visited by alligator-like animals, now termed Arclisegosaurus, whose bodies were covered by hard, horny scutes or scales, held together much after the manner a slater now adopts when he tiles a house. These creatures were five and six feet long, and were adapted to a purely marine life. They were the principal and most powerful animals of the age I am speaking of. In one of the states of North America, Ohio, no fewer than twenty-seven species of animals have been found, belonging to ten dif- ferent genera. Most of them are batrachians, but one has great affinities to the serpents. The atmo- Fiir. : >.-;'. . X^ v2i^ " - -"- VZ "IS) -.' '' ; >J->T^ Nearly perfect fossil skeleton cf Archcegosaurus. THE STORY OF A PIECE OF COAL. 89 sphere differed little from its present condition, being neither denser nor more rarified. This you may prove for yourself by the impressions of rain- drops preserved in the Carboniferous sandstones. The great drops were driven by the wind aslant, so that there is even now indicated the very quarter from which the wind blew at the time ! The passing shower over, the sun peeped forth from behind the dark clouds, and his heat baked the mud, and cracked it, just as he docs now the bottom of a clayey pond. These sun-cracks were subsequently filled up, some- times by sand of a different colour, so that they are fossilized as truly as the shells and plants. The same sandstones yet bear the trail-markings which the marine worms left after they had crawled over them when in a soft state. Occasionally you may even come across their burrows or holes ; whilst the flagstones also are impressed with ripple-marks left by the retreating tides ! Although the sea-bottom was so shallow in the neighbourhood of the great forests, I should state that many miles further out it gradually shelved deeper, until there was an area where " blue water " was at- tained. Previous to the formation of the coal seams, which as a rule belong to the upper part of the for- mation, the sea was fairly alive with animals of all sorts of natural history orders and classes. Coral banks, with animals putting forth their beautifully coloured tentacles, more various than the rainbow hues, stretched over many leagues of old Devonian 90 THE STORY OF A PIECE OF COAL. FJ>. 34. rocks, and, as the area was slowly submerging at the time, their united labours, in the course of ages, produced no small portion of what is now termed the " Mountain or Carboniferous Limestone." Shell- fish, allied to the existing nautilus, found in these purer waters, free from land sediment, the essentials of their well-being. In the limestones which their dead shells helped to form there are no fewer than thirty different species of nautilus ! They had rela- tives termed Qoniatites (long since died out, for they did not possess the hardiness of their congeners), whose chambers were fashioned in a zigzag or angular manner. Then came another group of shell-fish, equally near by blood, the Gyroceras, whose coils did not lie so closely together as those of the nau- tilus. One other class of ce- phalopods are now known as Ortlioceratites. They were also chambered, but w r ere straight instead of being coiled. The limestones of this age are crowded with immense numbers both of species and individuals belonging to these genera. Of them all the Orthoceras was per- haps the most dreaded, partly on account of its size (some of their shells being three feet long, and as thick as a man's leg), and partly on account of their voracious habits. Fancy them, as I have frequently Goniatites sp'iericus. THE STOKY OF A PIECE OF COAL. 91 seen them, with their last chamber surrounded with a circle of long arms, that would indicate no slight danger to bathers nowadays ! Hundreds of thou- sands of these creatures existed. Indeed, they were the scavengers of the Carboniferous seas, eating up everything that came in their way, and perhaps not particular about preying upon a weakly brother when appetite prompted them. In Scotland, in many parts of the limestones formed at this time, the strata, for hundreds of feet in thickness, are Spirifcr strkitus, Derbyshire; 6 valve showing internal coil ; c portion of coil. composed of hardly anything else but the accumu- lated shells of Orthoceratites ! At the bottom of the sea in which these cepha- lopoda lived and flourished there were gathered together immense shoals of a peculiar shell called Spirifera, now extinct. Scores of species of this particular shell lived and died there, for it was the period when the family (Bracliiopodd) attained its maximum of existence. In fact, they occupied the 92 THE STORY OF A PIECE OF COAL. place in those earlier seas that cockles and mussels do now. Their anatomy was very peculiar, each shell-fish being furnished with a peculiar coiled-up apparatus which it could protrude so as to produce currents that brought to it its food. Small, but beautiful crustaceans, of a race then fast dying out, still swarmed the waters. Formerly you may have heard of them as Tiilobites those of this age are christened Phillipsia. Their family had exercised a sort of crustacean oligarchy during previous geolo- gical epochs. But the Carboniferous period saw the last of the race, and its limestones became their tomb. I am told that the geologist knows few fossils more beautiful than these little trilobites. The cream-coloured matrix in which they are im- bedded, and the perfect and ornate characters of the fossils themselves, cause them to be greedily col- lected and much admired. In the same sea were hundreds of species of shells besides, all of which thronged together to enjoy a common life ; but to mention them separately would be to convert my story into a tedious detail. I should be lacking greatly in memory, however, if I were not to mention a most abundant and peculiar family, allied to the star-fishes and sea-urchins of the present day I mean the Crinoids. The common feather-star of recent seas most resembles the upper parts of these extinct animals. But the tentacles of the latter were longer, whilst each was subdivided into branches. When at rest, these closed around the body like the THE STORY OF A PIECE OF COAL. 93 Fij?. 36. PALAEOZOIC CRIXOIDS. 1. Plati/crinus trijintiddctijlns, Curb Lime stone, Ireland. 2. Actinocrinus tricuspidatus, Curb. Limestone, Uel gium. 3. Ijhtyocrinus hvi'is, Silurian Limestone, North America. 4. Eucalyijtocrinus rosaceus, Devonian Limestone, Kifel. oa. Actino winus triacontadactylu.<. Garb. Limestone, Lancashire. G. Taxocrimn briarcxs, Devonian. 7. Cuprcssocrinus. 8. Rkodoc inut crc THE ST011Y OF A WEOE OF COAL. 93 petals of a tulip. Again, each was fastened to a jointed stem, which anchored itself by roots to the sea-bottom. Submarine forests of these crinoids covered miny square miles of the rockier portions, and their graceful outlines and motions in the water, as well as their bright colours, were sufficient to induce ad- miration. In Derbyshire the limestone is frequently composed of their broken and aggregated stems, compacted so firmly as to form a marble capable of receiving a high polish. I have no doubt you may have seen mantel-pieces formed of it, and have wondered at the strange forms which seem to be enclosed in the solid rock. As these dead shells and other animal remains accumulated along the ocean- floor to form a limestone that should afterwards be easily identified by their imbedded forms, almost every individual was coated by minute sea-mats. No Honiton luce of the present day ever ex- celled in grace and elegance that which was fashioned by these lowly animated beings. In the solid masses of the Carboniferous limestone you may find Them festooning shells and corals ; and few objects afford greater delight to the geologist when he comes across them. The single corals also that is Pent r em >tcs flo- realis, Curb. Limestone, Il- linois, United States. This fossil almost makes up the bulk of the limestone. 06 THE STOUY OP i PIECE OP CJOAL to say, those which did not grow in reefs, but lived solitary on the sea-bottom were not inferior in .beauty to any now existing. Their fringe of gorgeously coloured tentacles made them appear like so many animated flowers ; and thus the dark caves of ocean then bore many a flower that was born to blush unseen. Slowly, through count- less myriads of years, the Carboniferous limestone increased to its present thickness, principally by the Fig. 38. d Fentremites, enlarged, a Showing the plates, &c., which make uj the test. accumulation of dead shells. The sea-water con- tained more or less of carbonate of lime, which the shell-fish absorbed in order to build their dwellings, just as the trees did carbon that they might form wood. In this way the minute particles became ultimately condensed into rock masses. Meantime, the water w r as animated by little creatures that would have evaded human eyesight, although their THE STORY OF A PIECE OF COAL. 97 forms were not a whit less elegant and graceful than these of their larger neighbours. Their tiny shells ff,il to the sea-bottom, and there formed a limy mud, which acted as a fine cement for the bigger fossils. As time passed on, the sea actually became shallower, by reason of the vast numbers of or- ganisms lying on its floor. The weight of sea-water pressed them into a solid limestone rock, such as you now behold it. Can you wonder, after this, that such a deposit should take a high polish when worked, or that the marble thus produced should bo speckled and marked by so many strange forms as you sec it in your mantel-pieces or pillars ? In the shallower waters of the sea, and sometimes even in the marine lagoons where the trees grew, multitudes of strangely-clad fishes swarmed. The largest of these, the Megaliclithys, or " great fish," possessed characters which linked it to the reptile family. Its teeth and jaws rendered it a formidable assailant, and its powerful build and rapidity in swimming made it the terror of its neighbours. In fact, the " great fish " occupied a place among the fishes of its time similar to that held in modern rivers by the pike; its size, also, being about the same. Time, however, would fail me to enume- rate the various kinds of fish that lived in the same epoch that I did. From four or five feet in length, to thousands no bigger than the common stickleback, nearly all were covered with enamel plates instead of horny scales. Indeed, horny-scaled fishes did not 98 THE STORY OF A PIECE OF COAL. come into existence for ages afterwards. In many parts of Lancashire, in the shales which overlie the coal-seams, these shining enamelled plates may he turned up hy the thousand. The smaller fishes haunted the shallower lagoons overhung hy club- mosses and ferns, and the dim light that broke Fig. 39 Teeth ami Scales of Carboniferous Fish. through these was often reflected from the sheeny mail of Paltconisci, as they wantoned and gambolled, unaware of " great-fish " lying near. When the muddy bottoms of these reaches and lagoons became after- wards hardened into coal-shale, the dead fishes lying there, whose hard covering had protected them from decay, were entombed and passed into a fossil state. Fig. 10. a Lcjiidodcndi-on (restored); b $ c impressions on back; d stoir. with leaves; e leaflet ; / fruit ot' Lepidodendron, called T epidostrubn8 1 y shoeing spores iu bracts of fruit. a Sigilfaria (restored) ; 6 leaflet ; c # d impressions on bark ; e section of stem ; / portion of cyliader, magnified. THE ST011Y OF A PIECE OF COAL. 103 Fig. 42. But what tongue can describe the vegetable won- ders of the forests where I grew ? The woods were so thick, and the gloom so impenetrable in con- sequence, that it required a keen eye to make out individual peculiarities. Fancy Lepidodendra four or five feet in diameter, and as much as rii'ty or sixty feet high, and yet nothing but gigantic "club- mosses ! " Their long leafy ribbons waved like the leaves of the aspen, and, where these had fallen oft', the bark was most gracefully and geo- metrically patterned from their attach- ment. Thirty or forty different sorts of these immense club-mosses existed at the same time, each characterized by different leaves - . , mi Microscopical section of Fossil \\ ood, from and bark. The gigan- d;iy imi _ stonc nojulcs . oiaiuu ' n< t : c Sly ill (i ) uu w ere nearly related to them, the main difference being their longer leaves, straighter stems, and the largei marks made on the bark. The roots, also, of this latter class of trees were very peculiar, and stretched through the mud on every side, seeking a firm foun- dation for the tree to which they belonged. Shooting many feet above these great club-mosses were huge " horse-tails," as easily distinguished from the rest as 104 THE STORY OP A PIECE OF COAL. the aspen-poplar nowadays is from oak and elm. These are called Calamites, and truly they were extra- ordinary objects. You have only to magnify the little Fig. 43. Vertical section of Fruit of Calamity magnified. " horse-tails " now growing in ditches, until you see them fifty and sixty (or more) feet high, and you would have the best restoration of these Calami tea THE STORY OF A PIECE OF COAL. 105 that could be imagined. There were many species, characterized by fluted joints, and by difference of foliage. Here and there, but more sparsely scattered, were graceful tree-ferns, whose former fronds had left great scars on each side the trunk. The higher grounds were occupied by peculiar species of pine, bearing great berries as big as crab-apples. The Fig. 44. Transverse section of Fruit of Calamite, magnified. humid morass was densely covered by a thick under- wood of smaller ferns, which grew there in rank abundance. The equable temperature, rich soil, an'] 1mm id atmosphere were just the needful accessories to the growth of vegetation of the class I have men- tioned. It consequently nourished at a rate of which 100 THE STOl'A* OF A 1'IECE OF COAL. Tig. 45. \\c can form but a poor idea from the present. TLo accumulated trees, ferns, &c., were very great, and these gathered in immense quantities over the entire area. I mentioned oefore that there was a slow sinking or sub- mergence going on. Well, oc- casionally, the tides brought up silt and strewed it over the de- composing vegetation. In fact, many of the forests were actually buried thus, and their trunks are frequently met with standing erect in solid sandstone rock. But though the covering-up ot the vegetation prevented the liberated gases from escaping, it also obstructed for a time the growth of other trees. The latter could not well flourish on sand- banks, and so they were limited to conditions elsewhere similar to those I have mentioned. But as time elapsed, the old circum- stances returned. Another forest grew on the site of the older, to be buried up in its turn. During countless ages this alter- nate growth and covering-up went on, until in some places, as in the South Wales coal-field, there are no fewer than one hundred Fossil Fern Fig. 46. ,<->^^" -^ C-ilamjtes (a re .tored) ; b enlarged ncl- emnitcs puzosianus). Fig. 70. Oolitic "Thunder-bolt (#. albrcciatus). of course, you would not expect to find the land creatures well represented), and come to the Purbeck WHAT A PIECE OF PUltBEGK MAllBLE HAD TO SAY ! 15U Oeds, then you will be astonished at the large number of species of marsupials, and the great modification and adaptation in their habits which had taken place. The streams entering the lakes where the Purbeck marble was formed were much more Fig. 77. Oolitic Wood X -4- Fig. 78. Oolitic Wood x 30. likely to carry the carcasses of these dead marsupials there, and therefore the bottom of that lake was more likely to be a richer cemetery of their remains. 160 WHAT A MCE OF PURBECIC MARBLE HAD TO SAI- ! Some of the Oolitic strata are much more favour- able to the preservation of organic remains than others, and these invariably give us a glimpse of animal and vegetable life which, although of a Microscopic sections of Fossil Wood, from Scarborough x 100 much lower organization on the whole than the present, was admirably adjusted each to the other. Thus, the fourteen species of marsupials above mentioned, were all obtained from a thin seam, thre* WHAT A FIECE OF PUKBECK MAEBLE HAD TO SAY ! 161 or four inches thick, in the Purbeck series, and from an excavated area of about five hundred square yards ! Of all these rich fossiliferous deposits, how- ever, perhaps the most interesting is at Solenhofen, where there occurs the stone of that name, much in use now, I am told, for lithographic purposes. The sediment of which it is composed is very fine, so that the quality which gives it its economical value to man is exactly that which has rendered it such a splendid mausoleum for the fossils of the Oolite. Forty years ago there had been obtained from this one deposit no fewer than between two and three hundred species of fossils, of which seven species were those of flying-lizards, or Ptcrodactylcs ; six species were those of huge saurians ; three were tortoises ; sixty species were fish ; forty-six were crustaceans ; and twenty-six were insects, which had probably been blown from the land by the breezes, and eventually found a watery grave, and an immor- tality they never dreamt of. I have already spoken a little of the peculiar vege- tation of this period of the Cycads and Zamias and Tree Ferns, which had taken the place of the Cala- mitcs, Sigillarias, and Lepidcdendra of the Palaeo- zoic epoch. Besides these, there flourished other plants, now regarded as characteristically Australian, of which the Araucarian pines are examples ; several species are found in the Inferior Oolite, whose cones showed that they lived and flourished not far distant. Then, again, in the so-called "dirt-beds" of the M 162 WHAT A PIECE OF PURBECK MARBLE HAD TO SAY ! Portland stone, and also of the Purbeck beds, you have evidences, not only of old land surfaces, but also of the dense vegetation which covered them. These " dirt-beds " plainly indicate the extended period during which these old cycadean and pine forests grew. Their remains are now found silici- fied, their trunks and stems lying recumbent amid the "dirt," whose fresh- water shells tell you how it had been the shallow bottom of a lake before it was a forest-bed, and that it was there its rich black Fig. so. * soil was accumulated ! The Cycads are flattened some- what by the pressure of the overlying beds, so that their bracts or scales give them a peculiar appear, ance, which, I am told has earned for them among thB quarrymen the name Cycadoidea, or " Crow's Nest." O f " Crow's Nests." As you are perhaps aware, the sea was still the home of the great fish-lizards, Ichthyosaurus, Plesio- saurus, &c. On the dry land the reptile family was represented by an abundant group, which goes under the general name of Dcinosauria, or " terrible rep- tiles." Judging by the size of some of them, this name is not badly given. But by far the most characteristic feature about these huge land reptiles was their near anatomical relationship to the birds ! You hear a good deal of foolish talk now about WHAT A PIECE OP PURBECK MARBLE HAD TO SAY ! 163 "missing links," and those who make use of it little know that all the fossils are, more or less, of this nature, and fill up gaps in the natural history classi- fication. Some of the reptiles of which I am speak- ing walked on two legs, like great Cochin China fowl, and with their hind quarters much more strongly developed than their fore limbs. In this respect they resembled, amongst the reptilia, the position of the kangaroo, which, as everybody knows, Fig. 81. Mcgalosaurus a great terrestrial reptile. generally uses only his huge hind legs, his fore limbs being much smaller and weaker. One of these land reptiles, named Compsoynatluis, whose remains have been found in the Stonesfield slate, and which was only about two or three feet in length, is the nearest approach, in its general structure, to birds of any yet made known. As you are aware, nearly all reptiles are egg-bearing in their habits, and the fossil eggs of 164 WHAT A PIECE OF PUHBECK MARBLE HAD TO SAY ! the Oolitic reptiles have heen met with, showing that, so long ago as the Oolitic age, this class had the same hahits as their diminutive representatives of the present day. But what is very remarkable is, that whilst the reptiles of this period had bird-like characters, the only birds known had reptilian pecu- Fi Archesopteryx (restored), from the Oolitic Limestone of Solenhofen. liarities ! No doubt you are aware that these two great groups of animals, birds and reptiles, follow each other in ordinary classification. They do so in order of time, the reptiles first in their lowest grade as Amphibia (Labyrinihodonts) , which gradually rise WHAT A PIECE OP PUKBECK MARBLE HAD TO SAY ! 165 to a higher standard in the Ichthyosaurus, until they assume features which, as I ahove remarked, now belong wholly to birds. Singularly enough, the true birds follow soon after, and the first specimen you meet with shows, in the structure of its tail- bones, &c., that it had borrowed some of the anatomical peculiarities of the reptiles ! This bird had a long attenuated tail, like that of a lizard, with feathers bifurcating from each side down to the end. This strange bird is now known as the Arcliaoptcryx, and its bones, and even feathers, have been found beautifully preserved in the Solenhofen stone. Here you have, at any rate, a meeting- ground on which two of the great divisions of the animal kingdom exhibit their mutual descent. It is a suggestive fact for those of my hearers who are sceptical about "missing links ! " The ages which have passed away since these things occurred are bewildering to those who are anxious to know, in so many years, how old the world is, as if that fact would add anything material to their real knowledge. At the time of which I am speaking, the area occupied by the Himalaya Moun- tains was a deep sea-bottom : that great mass has been slowly elevated to its present great height since the era of my birth. The Jura Alps were in the same condition, and have undergone similar ele- vation. One generation of animals and plants after another has passed away from the earth, having been slowly pushed out of existence by newly-formed 166 WHAT A PIECE OP PURBECK MABBLE HAD TO SAY ! species, better fitted to the alterations effected through the changes in physical geography. The whole of the Oolitic strata of soft sands, oozy lime, and dark mud, as well as the beds of loose fresh- water shells, have undergone chemical action and change, and been transformed into sandstones, lime- stones, shales, and Purbeck marbles. Our family has been in past times, and is now, a favourite with man in his endeavour to express his religious con- victions and festhetical feelings. We form the stone- work of his grand churches and cathedrals, and I myself have the honoured position of forming part of his altar, his christening-font, or his grave- slab! The tread of many generations of men has not effaced my lacustrine origin. Dynasties and religions have passed away, and been replaced by others breathing a more Christian and liberal spirit, just as the Oolitic animals were replaced by those of a higher organisation ; but I still form part of these grand structures, silently testifying to the endura- bility of nature over art, and yet myself a testimony that Nature herself is full of changes, and restlessly advances to a more perfect condition ! THE STORY OF A PIECE OF CHALK. 1G7 CHAPTER X. THE STORY OF A PIECE OF CHALK. " There rolls the deep where grew the tree, Oh earth, what changes hast thou seen ! There, where the long street roars, hath been The stillness of the central sea." TENNYSON. iT is so long ago that I can hardly remember it. My first recollections are of a white, muddy sediment, hundreds of feet in thickness, stretching along the bottom of a very deep Fig 83. lim~ Drntalina acu~ Dc.ntnlina gra- Dentalina Lor- lata, Chalk, leata, Chalk, cilia, Gault, iieiana, Chalk, Chaving. Ilminstcr. Folkstone. Kent, FORAMINIFERA FROM THE ENGLISH CHALK. sea. Of this oozy bed I formed an inconsiderable part. The depth of sea-water which pressed down 168 THE STOEY OP A PIECE OP CHALK. this stratum was so great that the light scarcely found its way through the green volume. Day and night the billows tossed and heaved above me. I Fig. 87. Fig. 93. DentaUna sul- cita, Cha!k, common. Marginullna compressa, Chalk, Charing. Fig. 91. Marginulina rancosta, Chalk, Charing. Fron dicu laria Vcrneuiliana, Chalk. Charing. Fig 92. Pyrulina acuminata, Chalk, Charing. Frondicularia Arcliiaciana, Chalk, Charing. FOEAMINLFEBA FROM THE ENGLISH CHALK. could hear the storm howl and the hurricane sweep over the surface of the sea, although they could not affect the bottom where I was lying. Before I THE STORY OF A PIECE OF CHALK. 169 awoke to consciousness in my oozy condition, I had existed in quite another form. The constant beat- ings of the Cretaceous sea against its barriers, and, more particularly, the vast quantity of mineral matter poured into it by tributary rivers, had caused Fig. C3. Fig 94. Tcxtularia trochus, English Chalk. Fig. 93. Textularla turris. English Chalk. Fig. 97. Textularla Bau- douiniana, English Chalk. FORAMINIFERA FROM THE ENGLISH CHALK. Gaudryina rugosa, English Chalk. Gaudryina pupoides, English Chalk. to be distributed through the sea-water a consider- able quantity of mineral matter. Of course, great though this quantity originally was, when diffused through the sea, it appeared so small as not to affect the real transparency of the water. The presence 170 THE STOBY OF A PIECE OF CHALK. of carbonate of lime (for such was a good portion of the mineral matter above mentioned) could only have been proved by delicate chemical tests. It happened, however, that there were organs sharp Fig. 99. Verncuilina trlcarinata, Kentish Chalk. Fig. 100. Lulimina obtusa (rare). Fig. 101. Tiulimina obliqna, English Chalk, Bulimina varialilis (rare), common. FORAMINIFERA FROM THE ENGLISH ClIALK. enough to detect even this small modicum. These belonged to a group of animals so minute that you could have put millions of them into a school- girl's thimble ! Each creature was a perfect animal nevertheless. THE STORY OF A PIECE OP CHALK. 171 It had a soft, jelly-like substance, which developed itself into feelers, that took hold of prey even smaller than itself. This soft body was enclosed in a sort of shelly case, beautifully ornamented, and Fig. 1C2. Fig 103. Bulimina brevis, Eng'isb Chalk. Bulimina Miirchisamana (rare). Fig. 104. Tm.nfa.tit~ in i Ufa inontiana, Gravesend and VTarminster. FOKAMINIFERA FROM THE ENGLISH CHALK. uniformly shaped. This case was manufactured out of the carbonate of lime, which has already been men- tioned as held in solution by the sea-water. Every cubic inch of water in all the vast ocean at whose 172 THE STORY OF A PIECE OF CHALK. bottom I was lying, was alive with these animalcules, everlastingly at work separating the mineral matter. It was quite impossible to see these little workers Fig. 106. Rosalind Lorneiana (rare). Fig. 1C6. Rosalind Clementiana, Kentish Chalk. FOBA.MINIFEBA FROM THE ENGLISH CHALK. that " out of water brought forth solid rock," and yet they were there. Their individual lifetime was very brief, rarely extending over a few days. But their THE STOKY OF A PIECE OF CHALK. 173 powers of reproduction were enormous, and thus they were always dying and generating. As they died, they began to sink slowly through the water. Fig. 1C7. Eolalina Cordieriana, English Chalk. Fig. ioa Gloligerina cretacea, English Chalk, common. FORAMINIFERA FROM THE ENGLISH CHALK. The sea was always full of their dead shells, which were gravitating towards the hottom, where they fell as lightly as the motes which float in the sun- 174 THE STORY OF A PIECE OF CHALK. beams drop upon the floor. Niglit and day, they were always alighting there, and forming a thin film. Century after century passed away, and still found these dead shells accumulating, until all the figures I have heard reckoned on the black-board near me I am now used in a schoolroom for the Fig. 105. G loligerina elevata (rare). Sagrina rugosa, Chalk, Charing. Fig. 110. Rotalina Voltziana, English Chalk. FORAMINIFERA FROM THE ENGLISH CHALK. purposes of arithmetic would not together give any idea of their numbers, even if they were all stretched out in a row ! You may think this is a bit of romancing, but it is not. A few days ago, a gen- tleman hroke a piece off me, and after powdering it and washing it with a fine camel-hair brush in THE STOKY OF A PIECE OF CHALK. 175 distilled water (so as to make sure of his experiment), I heard him tell a friend that he could show him Fig. 111. Eotalina Michcliniana, English Chalk Fig. 112. Rotalina umbilicata, Chalk, Gravesend ; Gault, Folkstone. FOKAMINIFEBA FROM THE ENGLISH CHALK. thousands upon thousands of fossil animalculic shells y/hich he had ohtained from this small piece ! These 176 THE STOEY OF A PIECE OF CHALK. minute shells belong to many genera or kinds, of which one called Globigerina is by far the most abundant. This genus lived along the bottom of the sea, and did not move, but .gradually and continually secreted carbonate of lime from the water, so that in this way Fig 113. Fig. 114. Cristi llaria rotulata, variety. Fig. 115. Cristellaria navlcula, Kentish Chalk. Tig. 115. Cristellaria triangularis, Chalk, Cristellaria recta, Chalk, Kent ; Gault, Folkstone. Charing. FOBAMINIFERA FROM THE ENGLISH CHALK. alone the limey mud would have increased in bulk, just in the same way that coral reefs grow at the present time. Although I am no bigger than a small orange, I can assure you there are scores of STORY OP A PIECE OF CHALK. 177 millions of fossil shells contained within my bulk. In fact, I am myself little more than a mass or congeries of the dead shells to which I before alluded. Every time the teacher makes a fig are with me on the black-board, he leaves thereon thousands of fossil Fig. 117. Fig. 118. Lit-j.ola nautiloidea, English Chalk. Fig. 119. Eotalina crassa, English Chalk. Fig. 120. Frondicularia tricar inata, Kentish Chalk. Flabellina rugosa, Kentish Chalk. FORAMINIFERA FROM THE ENGLISH CHALK. animalcule. If you will wash the chalk as the above- mentioned gentleman did, you may see these minute fossils for yourself; though, it is true, you would need a powerful microscope to enable you to do so. It was the gradual accumulation of these ani- N 178 THE STOEY OF A PIECE OF CHALK. malculic shells that formed the oozy mud at the bottom of the sea. The extent of this mud-bed was very great not less than scores of thousands of square miles in area. Notwithstanding the slowness of the deposition, and the infinitely minute creatures Fig. 121. FlaleUina Baudouiniana, English Chalk. Fig 122. Fig. 123. Fldbellina pulchra ;, Kentish and Cristellaria rotulata, English Norwich Chalk. Chalk and Green-sand, common. FOttAMINIFERA FROM THE ENGLISH CHALK. which almost wholly formed it, the accumulation went on until the mud had reached a vertical thickness of fifteen hundred feet ! What must be the enor- mous number of shells contained in this mass, and the number of centuries occupied in elaborating THE STORY OF A PIECE OF CHALK. 179 it, I leave you to guess. The rate of deposition was very regular, and I have heard that along the bottom of the great ocean called the Atlantic, there is actually now being formed a stratum very similar to that from which I was taken. Like it, also, it is formed principally by immense numbers of dead animalcule. The same species of Globigcrina is still living along the Atlantic sea-floor, and I am told, is still engaged in forming similar chalky ooze to that which its lineal ancestors formed countless ages ago ! Minute grains of chalk, of vital origin, are also abun- dant in my substance, and these, I am further in- formed, under the name of Coccolitlis, are in equal abundance in the Atlantic mud, where they exist under the lowest forms and types of animal life. I lay along the bottom of the Cretaceous sea for thousands of years, during which great changes took place in the oozy deposit, some of which I distinctly remember. I should have said that, besides carbo- nate of lime, there were diffused through the sea- water other minerals, among the rest, one called Silica, the basis of common sand. Well, some pro- portion of the minute animals inhabiting my native sea may have used this mineral instead of lime, so that their shells were formed of flint. These, of course, fell to the bottom along with the others, and were all mixed up together. By-and-by, a chemical change took place in the thick mud. It seems that the little grains or shells of silica have a tendency to separate from the lime, and to run together ; 180 THE STOEY OP A PIECE OF CHALK. consequently, the flinty little shells aggregated along the sea-bottom, and there formed what are now known as flint-lands and nodules. A chemical pro- cess, resulting from the decomposition of animal matter, caused some of the dissolved silica to be precipitated, and thus hastened the formation of flints. These layers of flint were formed at nearly regular intervals, the chemical changes being very Fig. 121. Microscopic Section of Polypothecia, a fossil siliceous sponge, magnified 150 diameters. From Green-sand, Carrow Well, Norwich. uniform. Again, another, and perhaps a principal, means of forming flint was by the decomposition of the animal matter, which was the means of precipi- tating the silica held in solution by the sea-water. I should also mention, that as the oozy bed increased in thickness, what with the weight of sea-water and the overlying mud, the lower beds began to be com- THE STOKY OF A PIECE OP CHALK. 181 pressed into a solid form. As soon as this took place, they passed into real chalk, of which I found myself a part. That this flint was originally soft you may see by its having exactly the san^e kind of shells, &c., sticking in it as you find in the softer chalk. I am reminded of the way in which the siliceous material would separate from the limey mud by a process Fig. 125. Microscopic Section of Poli/pothecia,& fossil siliceous sponge, magnified 150 diameters, from Green sand of \Varniinster. which goes on in the manufacture of pottery. When the ground flints have been reduced to a fine powder, and then mixed with clay in the soft putty-like con- dition, there is a tendency for the silica to separate from the rest, and run together into nodules, so that it is very necessary to prevent by constant agitation. This exactly illustrates how the original silica dif- 182 THE STOHY 07 A PIECE OF CHALK. fused through the original chalky ooze segregated into flint nodules. I have a distinct recollection of the creatures that inhabited the sea whilst I was lying along the bot- tom. I am told there are few objects like them living in the seas of the present day. Even those which approach nearest in resemblance differ in somo point or another. The most remarkable of these inhabitants of an extinct ocean were a series of large sponges, called by scientific men Paramoudrce, but better known in Norfolk (where I come from) as "Pot Stones." These were originally -sponges which grew one within the other, like so many packed drinking- glasses, sometimes to the height of six or seven feet. Through the whole set, however, there was a con- necting hollow, which is now filled with hard chalk, the rest being all pure flint. It is very remarkable how these sponges became transformed into their flinty condition. As sponges, they were full of what are called spicula that is, flinty, needle-shaped crystals, which act the part of vertebra to the sponge. You may find them in the sponges of the present day. When the " pot stones " existed in this state, as the sponges died and began to decompose, they served as nuclei to all the flinty particles of animalculic shells diffused through the mud, whilst the decomposing animal matter of the sponges pre- cipitated the soluble silica round them, and thus solidified them all together. These replaced the decaying matter of the sponge little by little, THE STORY OF A PIECE OP CHALK. 183 until the original Paramoudrce were turned into " pot stones." That the flint of these " pot stones " was originally soft may be proved by the fact that fossil shells are often found embedded in it. The other creatures I most distinctly remember are now found in a solid state in the chalk, and are com- monly known as "Fairy loaves" (Anancliytes) and "hearts" (Micraster). They belong to an extensive family still living, and known to the fishermen (who often dredge them from the bottom of the present sea) as " Sea-urchins," on account of their spiny Fig. 126. AnancTiytcs ovata, or " Fairy-loaves." The existing sea-urchins crawl along the bottom by means of innumerable suckers. Many a time have the fossil fairy loaves thus crept over where I lay. The " hearts " were similarly covered with movable spines or bristles. The family to which these objects belonged is now known bsEchinodermata, or "spiny-skinned," as the name means. It is as cha- racteristic of the chalk formation as the Ammonite family is of the Lias, or the Trilobitcs of the Silu- rian. Some of these "sea-urchins " were most lovely 184 THE STORY OF A PIECE OF CHALK. Fig. 127. objects. One group (Cidaris) is ornamented by rows of alternately small and large knobs, to which club- shaped spines were formerly attached. These spines are abundant in chalk. But the commonest objects I remember are those now often found in the chalk as well as the flint, and which are known as " Thunder-bolts." These fossils, how- ever, are individually only part of the creature to which they originally belonged. They were the solid and terminal bones of a species of "cuttle-fish." After the latter had died, and lay embedded in the chalky mud, the soft and fleshy parts decomposed, and left only the harder portions to be preserved. Sometimes the thorns, which were attached to the long arms f these creatures, as well as the horny portion of the beak, are also found fossilized. During my time, the Belem- nites (as these fossils are now called) swarmed the seas in millions ; in fact, they were thorough scavengers, and de- voured any garbage they came across dead fish, rotting fairy loaves, &c., and even one another. Here and there, grouped in the hollows of the sea-bottom, lay nests of shells (Terelratula and Rliyn- Naturai Flint c ^ on did) . They are commonly called castofp7t?-rtl those enormous creatures, Phantoms, inferior intelligence (At least so seeming), to the things we have passe- 1, Resembling somewhat the wild habitants Of the deep woods of earth, the hugest which Hoar nightly in the forest, but ten-fold Jn magnitude and terror; taller than The cherub-guarded wall of Eden, with Eyes flashing like the fiery swords which fence them, And tusks projecting like the trees stripped of Their bark and branches what were they 'i LUCIFER : That which The mammoth is in thy world; but these lie By myriads underneath its surface." BYRON'S Cain. N outline of the biography of even such a humble individual as myself will not be without interest. I need not intro- duce myself in learned mineralogical language ; for there is not a boy living, old or young, who has not made practical experiments on inc. But as clay is not limited to any geological formation, but occurs most abundantly in the later deposits, perhaps it may be as well for me to say to which period I belong. In the ol(ter rocks, what was once clay has sine* 194: THE STORY OF A LUMP OF CLAY. taken the form of slates or shales, subsequent alter- ations having brought about this change. I may say, therefore, that I belong to that period termed the Eocene a period remarkable for the great influx of warm-blooded animals. This period is the first of that last great division of geological time called the Tertiary. Of these I shall speak presently. The " London Clay," as it is termed, is the parent deposit of which I am elected spokesman and repre- sentative. London has been chiefly built out of this huge bed of clay ; whence its geological name. I have a dark bluish-brown appearance, and in some places the fossils enclosed are assembled in great abundance. Do not confound me with the clay beds which will be referred to by-and-by, and which belong to the Glacial or "Ice" period. No mistake could be greater, although very frequently our general appear- ance is much the same. It is when you compare the fossil remains found in our beds only, that you would form a just opinion. I was born ages before the clay above mentioned, and, although of marine origin, I came into the world under vastly different circum- stances. When I was born, a nearly tropical climate existed in what is now Great Britain when my neighbour was formed the climate was arctic. I made my appearance at the commencement of the Tertiary epoch he did not come until the final close. Between this beginning and end, this extreme of warm and cold climates, a long period of time had elapsed, THE STOIIY OF A LUMP OF CLAY. marked by the deposition of thick strata, some of whose members will presently tell you what occurred meanwhile. But, from the time when I was formed to the present, I know there exists a gradual series of beds, in which fossil plants and animals are im- bedded, whose types link those of the past with the present living fauna and flora of the globe. The Eocene formation comprehends other strata than that of which I form a part, but I do not think I am egotistic in stating that ours is regarded usually as the principal member. The total thick- ness of these beds is over two thousand feet. The upper series are w r ell developed in Hampshire and the Isle of Wight, where they bear evidence of having been de- posited in fresh water. These are represented on the Continent by the beds of the Paris basin, famous to geologists as having yielded to Cuvier the first materials for the comparative anatomy. Taking the upper Eocene strata in England, you find a gradual transition from purely marine to purely fresh-water conditions, the Headon series containing shells and other organic remains usually found under both circumstances. The Brackiesham sands are crowded with fossil shells, chiefly of Turi- tclla, indicating how slowly such beds must have n of ditto. young science of 196 THE STORY OF A LtJMP OF CLAt. been formed, and how suitable was the ancient sea bottom to the luxuriant development of these mol- luscs. I should also mention that underneath the London clay proper is a series of strata, chiefly of sands and gravels, ranging to a total thickness of nearly two hundred feet. My hearers who have carefully studied the geology of older formations, will see that a marked feature about these newer deposits is their very local extension. Whereas the older beds are almost world-wide in their distribt:- Fig. 137 Fig. 133. Kummulitic Limestone. Ditto. tion, the newer are so limited that it is very difficult to identify their exact position in different countries. The only exception to this rule, perhaps, is the enor- mous extent of the Nummulitic Limestone. In the old rocks all over the world you see fossils common to them, but every stratum in the more recent deposits is marked by its own suite of shells, &c , just as every eea now possesses its own peculiar fcrms of life. THE STORY OF A LUMP OF CLAY. 197 I was formed along the bottom of the sea, at no great distance from land, and yet far enough off for the sediment brought down by the rivers to have had its coarser particles precipitated before it reached the area over which my parent stratum was laid. Consequently, the muddy matter which there fell to the bottom was of a very impalpable charac- ter. The distant land was watered by large rivers, whose mouths debouched into the sea, and furnished it with the sedimentary material whose accumula- tion, to the thickness of nearly five hundred feet, ultimately formed the London clay. This land was clothed with a gorgeous and luxuriant flora, more like that fringing the banks of the Indian rivers, or the islands of the Malayan Archipelago, than any elsewhere growing in the world. Principal among the tropical forms were the palm-trees, whose grace- ful leaves hung over the water, and were reflected in its rippling depths. The succulent fruits of these palms fell in the stream in immense numbers, sometimes literally covering the surface, and were carried seawards. In some places where the clay was forming, these fruits, now known as Nipadites, accumulated to an extraordinary thickness, as in the Isle of Sheppy, where no fewer than a dozen species have been met with. In this locality alone, no fewer than one hundred and six species of plants have been found. You will see the correctness cf my inference that an Indian climate and scenery existed in England during Eocene times by-and-by ; 108 THE STORY OF A LUMP OF CLAY. but, meantime, I may say that the only places where palms now grow, whose fruit nearest resembles these of the London clay, are the Moluccas. Tree- ferns and fan-palms, also, were not lacking in the brilliant landscape; whilst gum-trees, Banksias, gourds, melons, bread-fruit trees, &c., completed the list. The rivers which ran through these thickets of tropical vegetation were haunted by crocodiles and gavials, lying in wait to seize the harmless Paliwilieria which might come to drink or to bathe themselves in the stream, after the fashion of their nearest living representatives, the tapirs. Opossums swarmed in the forest, and there is good reason for believing that, towards the close of the period I am describing, monkeys were intro- duced in what were then English woods ! At dusk, large bats, not unlike those of the Indian islands, made their appearance. Some of the fish which still lived, in the rivers were ganoids, that is to say, had bony-plated enamelled scales, like the Polyp- terus of the South African rivers. The remains of these fifhes and bats have been found in some abun- dance rear Woodbridge, in Suffolk. Lazily lurking in the flowery brakes of the forest were huge serpents, some of them as big as the boa-constrictor, and possessing characters now distributed among that class, and the pythons, colubers, &c. In the rivers, and also in the adjacent seas, swam terrible water- snakes, of an enormous size, and with vertically flattened tails, tin better to enable them to swim. THE STORY OF A LUMP OF CLAY. 199 As you would expect from such an association of aquatic dangers, many of the land animals fell a prey, and portions of their carcasses were either deposited in the river mud or carried out seawards. Hence I can tell you something of them, and point out a few leading peculiarities. Chief and com- monest among them were the tapiroid animals, to which 1 have already alluded. These harmless creatures were lighter built than the modern tapir, Fig. i:;o. Palxothcrinm magwnn. although, like that species, they had a short pro- boscis. Their name of Pdlseotforium, or "ancient beast," is well deserved, as, with the exception of the marsupials, or pouched animals, they are really the oldest warm-blooded quadrupeds with which I acquainted. They were thick-skinned or " pachy- nm dermatous " animals ; but, like many of the early types, possessed characters which are now more 200 THE STORY OF A LUMP OF CLAY. or less distributed among at least three different groups. The modifications of the higher animals, at the time I am treating on, were necessarily fewer than at present, when such an enormous zoological and physiological " division of labour " has ended in more marked specific specialization. Hence the Palxotlieria had characters which relate them to the tapir, horse, and rhinoceros ! About half a score different species lived together, their sizes ranging from that of a decent horse to that of a pig. Closely Fig. 140. Anoplotherium. allied to this extinct creature was the Anoplotlierium, or " harmless beast," as both its name and its struc- ture implied. The most remarkable feature about this creature was its long and powerful tail, which helped it when swimming, just as that of the otter does now. The Anoplotlieria, however, were perhaps more abundant in what is now France than in England. Some of them were very small, not much larger than a rabbit, whilst the largest THE STORY OF A LUMP OF CLAY. 201 certainly did not stand higher than three or four feet. They usually frequented the marshy places, and were very fond of wallowing in the mud. Like their relatives first mentioned, they had various zoological peculiarities, among which was the addi- tional relation to the modern camel. The Chseropo- iaums , or " river hog," was also a genus of the thick-skinned tribe, and stood really as a link be- tween the Anoplotherium, and the modern Peccary. Its habits, however, were not so harmless, as its teeth indicate a tendency to carnivorous habits. The Dichdbune so called from the deeply-cleft nature of its teeth was allied to the group I am describing. The Hytenodon was a truly carnivorous animal, its jaws being even better adapted for cutting flesh than those of the modern feline tribe. In some parts of Europe there abounded an animal called Anthracotherium, from its remains occurring in the peat-bogs or lignite-beds of this age. Like that just described, it was of flesh-eating habits; as was also another, very nearly allied to the modern weasel. There also lived Arctocyon, a bear-like marsupial ; Coryphodon, allied to tapirs ; Ancliitheriuin (perhaps one of the most generalised types of mammals, allied to horses on one hand, and tapirs on the other) ; Phenacodus, a more generalised type of mammal still, out of which you might make anything, &c. These groups of extinct animals connect living 202 THE STORY OF A LUMP OF CLAY. types that would never have been harmoniously blended. It is the moral of Mirza's vision over again the extinct forms have fallen through the trap-holes of the great viaduct of life, whilst only the recent forms have arrived safely at the other side ! You will have seen that, as far as it goes, the testimony of the mammalia is supplementary to that of the vegetation, &c., all tending to prove what I first stated that a nearly tropical climate ruled in English latitudes during the Eocene period ! The evidence of the marine organisms (with which, of course, I am better acquainted) is exactly to the same point. Just as the Tertiary epoch is remark- able for its large introduction of higher types of animal life, so it is also for the greater influx of genera, animal and vegetable, of living types. For the first time, among shell-fish, you recognise in the fossils of these deposits, forms which are common in existing seas. But it is not in British latitudes, but in tropical, that you meet with living genera allied to the fossil. The old Nautilus still kept its place, and several species lived in English seas, although it is now scantily represented only in the Indian Ocean. Huge Volutes, beautiful Cones, Mitres, Terebella, Eostellaria, Typliis, &c., abounded ; and the very mention of these names at once conveys to the mind of the conchologist ideas of tropical seas. The fish which lived in the same seas were also of a type commoner to warmer areas than to THE STOHY OF A LUMP OF CLAY. 203 ours. Many species of sharks abounded, some, as for instance, Carcliarodon, being of immense size; for the teeth of the largest have been found six inches long, and five broad at the base. Turtles lived in these seas and bred there ; for carapaces of all sizes, from the juvenile to the adult, are deposited in that part of the mass to which I belong, forming the Essex cliffs. As you are well aware, the turtles are now almost entirely confined to the tropical and sub- tropical districts. You see, therefore, that I have abundant evidence for warranting me in my statement, that at the time I was born, a warm climate prevailed here. What it was before, I cannot say; but I know that even before the close of the Eocene period, this warmth had already decreased very considerably. You will, of course, remember that between the beginning and close of this period, there had elapsed time sufficiently long to enable more than four thousand feet of material to accumulate as strata. The changes which took place in the physical geography meantime were very great. I am speaking of a time when the Apennines, the Alps and Pyrenees, had not been elevated nay, when the rocky material now forming a portion of their flanks was being deposited along the sea- floor! In England and France, marine conditions had gradually given place to lacustrine, and large lakes had occupied the area previously covered by the sea. During the time that these changes were going on. 204 THE STORY OF A LUMP OF CLAY. the climature was slowly toning clown. The fossil vegetation met with very abundantly in strata of Upper Eocene age in Hampshire, show you this very plainly. Although it includes types now pecu- liar to warmer regions, it is not so plainly tropical. The succeeding age, the Oligocene, hears out what I say, and from the period of my birth until the pre- sent, the register of the climate is very faithfully kept in the strata of the earth. I should remark that the term Oligocene is generally given to a thick and various series of strata intermediate in time between the Eocene and Miocene periods. The best English types of Oligocene strata, occur in the Isle of Wight, at Hempstead, Bembridge, Osborne, and Headon. Let me add a few remarks as to the latest news I have received of the animals in America which lived when I was being formed. Most interesting among them was the EoJiippus, the primeval ancestor of the Horse family. This creature had then four or five toes. The " splint bones " in the living horse represent two of these worn-out members. There were also other animals then living, such as Ddnoceras, whose descendants would hurdly recognise their ancestor. THE STORY OF A HECE OF LIGNITE. 207 CHAPTER XII. THE STOIIY OF A PIECE OF LIGNITE. " Sweet was the scene ! apart the cedars stood, A sunny islet opcn'd in the wood With vernal tints the wild-brier thicket grows, For here the desert flourished as the rose; From snpling trees with lucid foliage erownM, Gay lights and shadows twinkled on the ground; Up the tall stems luxuriant creepers run To hang their silver blossoms in the sun ; Deep velvet verdure clad the turf beneath, Where trodden flowers their richest odours breathe; O'er all, the bees with mm muring music flew From bell t') bell, to sip the treasured dew ; Whilst insect myriads, in their solar gleams, < lanced to and fro, like intermingling beams; So fresh, so pure, the woods, the sky, the air, It seem'd a pla^c where angels might repair, And tune their harp.s beneath those tranquil thud;-s, To morning songs, or moonlight serenades." ,T A M KS MON 'I'd O.M K K Y . ERSONALLY, I do not think I am such a familiar object, in England at least, as some of my fellow story-tellers. In some parts of Germany and Switzerland, and even in Devonshire, I am much better known under the name of " brown coal." The name I have assumed at the head of this story indicates, although under a Latin form, my vegetable origin. 208 THE STORY OF A PIECE OF LIGNITE. Of my affinity to the common household coal I will speak presently. My appearance bears out my Latin name, for few would mistake my mineralized woody structure for anything else than it is. Not- withstanding my dull brownish look, and the general absence of that pitchy glossiness which characterizes true coal, I have been formed under very similar conditions to the latter. My history is not less romantic nay, in my belief, is even additionally so, on account of my having come into existence at a comparatively recent period, geologically speaking. The epoch of rny birth is distinguished by the appearance of many genera of animals and plants which are still in existence. By some geologists, I am regarded as of Oligocene rather than Miocene age. That matters little, in view of the marvellous changes in the geographical distribution of animals and plants which has taken place since the Miocene period. The epoch of my birth was briefly referred to by the last speaker. It was the Miocene period, during which Europe was dotted by great lakes of fresh \ water, and covered with a flora more magnificent than any she had been clad with since the world began. The scanty species of the Carboniferous period pale before the gorgeous varieties of the Miocene. The flora extended to the very North Pole itself ! I am speaking of a period when no ice- cap existed in Arctic regions ; but when Iceland, Q -t>j tzbergen, and Greenland were clad with evergreen STOR OP A PIECE OF LIGNITE. 209 shrubs ; of a time when the Old World and the New were connected by an extension of land of which the Japanese islands, the Aleutian islands, and Van- couver's Island are now the only existing outliers. Central Europe alone maintained no fewer than three thousand known species of plants ! Of these, eight hundred species of true flower-bearing plants, besides ferns, &c., are found fossilized in the strata called the "Molasse." There is not the slightest Fig. 142. Deinotherium (restored). doubt that this number did not form half the real number, for these two thousand species have been entombed and fossilized wholly through accidental causes. The temperature of this period was considerably higher than it is at present, although not near so elevated as in the previous Eocene epoch. The nature of the plants found fossilized indicates an elevation ot about sixteen degrees above what it is now. Hence 210 THE STORY otr A PIECE OP LIGNITE. with physical circumstances suitable, one cannot wonder that a luxuriant vegetation covered every available spot of the dry land. As to the causes of this increased temperature, and, still more, of the extension of the Miocene forests to the very North Pole itself, I can only speculate. It is generally thought, however, that they were due to astrono- mical conditions of the northern hemisphere, partly similar to those now feebly affecting the southern, and also to such an arrangement of physical geography as insured the 'highest degree of heat and genial moisture. But even these conditions will not ac- count for plants to which light is such a necessary stimulant, growing within the Arctic circle, where there is a continued darkness for months together. I must give it up, seeing that eminent scientific men are in a quandary about it. All that I can say is, that no geographical agencies alone will account for the physical circumstances of the Miocene epoch. The Miocene strata, as I think I have before remarked, are most interesting to biologists, inas- much as it is here that they meet with the most abundant evidences of the direct ancestry of living animals and plants, which, since then, have been distributed by subsequent physical changes over the surface of the existing dry land. The fossil plants found in the lignite beds where I lay, before I was disinterred by the curious geo- logist, to tell him my personal experience, them- selves assist me in unfolding a wondrous tale, THE STORY OF A PIECE OF LIGNITE. 211 Lignite beds of Miocene age are to be found in Germany, Switzerland, Italy, Austria, Scotland, Ireland, Devonshire, Iceland, Spitsbergen, Green- land, Vancouver's Island, the Alaska islands, and elsewhere. All the plants forming this lignite afford most indisputable proof of their having grown on or near the spots where they are now met with. The petals, stamens, and pistils of the flowering plants are preserved in the fossil state, together with even the pollen ! Then you have the seeds, in various degrees of ripeness, whilst the leaves of many of the fossil plants have also fossil fungi on their backs, just as living plants are troubled with " smut," " bunt," or " rust " now. The ferns are to be met with in the circinate or crosier-like condition, as well as with the ripe spore-cases, ready to burst, on the backs of their fronds. Nothing could be more conclusive as to these various plants, flowering and cryptogamous, having grown near where they are now found in a fossil condition. The facts I have mentioned will show you they could not have been drifted to their present high latitudes by any flood or deluge, for that would most assuredly have disturbed such minute evidences of local growth as every bed of lignite affords. Taking this fossil flora in its general character, you will find that it is not so much what you would call European as it is cosmopolitan. Of the eight hundred species of flowering plants which geologists 212 THE STORY OF A PIEdfi 0# have already discovered in the lignites of Switzef* land, no fewer than three hundred and twenty-seven species are evergreens. Now, at the present time, evergreens are considered peculiar to climates where the winter is mild, and therefore where the leaves tire not often shed, as Italy, for instance. The majority of the species found fossil in Switzerland and in Germany have, since the Miocene period, migrated to the southern states of North Ame- rica. The next percentage continued European. Then, in succession, you find other species which have since been transferred to Asia, Africa, and even to Australia. The preponderance of the American types, both of plants and insects, is the peculiar character of the Miocene fossils in all the deposits of the Old World. That I was perfectly correct in my statement about the general increased temperature of this period will be evident when I submit to you a few analytical facts connected with this fossil flora. You will have to seek for the European types by the shores of the Mediterranean, and for the Asiatic in the Caucasus and Asia Minor, generally. The camphor-tiees now such a characteristic element in Japanese scenery are very abundant in the fossil condition in Miocene strata as far north as Iceland, Spitzbergen, and Greenland. How imposing was the vegetable kingdom in Central Europe at this time, you may guess by my enumerating a few of tho commoner genera. The Smilax grew everywhere, only equalled in THE STORY OF A PIECE OF LIGNITE. 213 abundance by the Dryandroides. Nine species of Fig-trees are known, whose nearest analogues now flourish in India, Africa, and America. The Proteacea family was very abundant. Fan-palms were a pecu- liar feature in the Miocene landscape, together with occasional Flabellarias. Other species of Palm were not lacking to adorn the scenery with their grace- ful foliage. Then we had abundance of Tulip-trees, Magnolias, Banksias, Sequoias, Vines, &c. You may guess, therefore, at the lovely aspect of the Swiss, Italian, German, and English lakes, set in a frame of such lovely vegetable forms, and whose banks were haunted by animals (which I shall presently describe) whose forms and affinities were quite as foreign to anything existing in Europe as can possibly be imagined. I was exhumed from my silent position in the pretty valley of Bovey Tracey, in Devonshire, where lignite occurs in several seams. There is not that abundance of vegetable forms stored up here as is to be met with elsewhere, especially in Switzerland. As far as I can remember, only about fifty species of plants are known from this English deposit. The intervening beds tell a tale as to the denudation of Dartmoor, and how the overlying beds came to be chipped off the hard granitic boss. Twenty of the plants found fossilized in this my birthplace are common to those met with under similar circum- stances in Switzerland. They are principally Ever- green Oaks, Fig-trees, Vines, Laurels, Gardenias, &vno ( Rf TTolpn's Pnnrls . .... 1 < Beds ' NpHlpRtniiP ftrits 1' g w 1 Upper Hcadon Beds *^ i v 'i x Ilcndon Beds Middle 5 H pd Lower . . . g OJ Upper Bngshot Sand. H j5* Bagshot Beds n/r- 1 11 (barton Clay. Middle JBrackleshamBeds i Lower Sand and Pipeclay. O p II London Clay and Bognor Beds. Woolwich and Reading Beds (Plastic I ,| _ Clay). Thanet Sands. f f f ( Upper Chalk. I DO pv.ii- j Lower Chalk . . j chalkMarli (Chloritic Marl. tH g-|' ^ Upper Grecnsund. P fc t Gault. o CO * f T Folkestone Beds. OQ s Lower 1 Sandgate Beds. O 1 ! DO Grcensai.d. j Ilythe Beds (Kentish ling). [Atherfield Clny. 6 | s "o f Weald Clay. i 6' c flipper Tnnbrldge Wells Sand. o ^ J Gr instead Clav. o M g ' Hastings . I^ower Tunbritlgo Wells Saml. ^ Sand, j Wadlmrst Clay, Ashdown Sands. \ ( { \ Ash burn ham Jicds. 286 APPENDIX. TABLE OF BRITISH FORMATIONS. I f Purbcck . Upper Purbeck Beds. Middle 1 ^ Lower ,, & 1 ( Portland Stone. &< 1 Portland . j Sand. ^ ^ ( Kimeridge Clay. {Coralline Oolite. Upper Calcareous Grit. Coral Rag. Lower Calcareous Grit. r> f i -ni / Oxford Clay and Oxford Clay { Kelloways fj ockt | Corubrash. T Forest Marble Forest Marble and fcH Bradford Clay. pa H "^ ' Great or Bath Oolite. 3 Great Oolite Stonesfield and Colly weston Slate and o ^j Northampton Sands. & & pa Fuller's Eartli. Upper Fuller's Earth. Fuller's Earth Rock. Lower Fuller's Earth. Q 8. 8 Ragstonc and Clypeus Bed. N 1 Inferior Oolite. Upper Freestone. Oolite Marl. Lower Freestone. 9 , Pea Grit. ( TT T . f Lias Sands. Upper Lias | ^ Clay and Shale. ^ . Middle Marlstone. I Lower Lias Clay, Shale, and Limestone. " fr- B la" /White Limestone or Wofetbury Bedg. rri g j 1 Red Marl and Upper Keuper Sandstone. & Keuper . < Lower Keuper Sandstone and Marl p i ( (Wateretones APPENDIX. 287 TABLE OF BRITISH FORMATIONS. Hunter Muschelkalk, absent in Britain. St. Cassian Beds, Dolomitic Conglomerate (of Ken per or Bunter age, Somerset and Glou- cester). Upper Red and Mottled Sandstone. Pebble Beds. Lower lied and Mottled Sandstone. p . Permian f Upper Red Marl. I Upper Magnesian Limestone ] Lower Red Marl. . . j Lowcr Magnesian Limestone I Red Marl, Sandstone, Breccia, and ( Conglomerate (Rothe-liegende). Coal Uppor Uoal Measures. ^ Measures. Lowe^CoarM^asures } Mciisill>os - 3 i Gannistcr Bwls. > K W CJ o OQ CO Millstone Grit \ Ar ^ , (Farewell Rock).} Moor Ro k ' C 1 ' N 3 s f Upper Limestone^ - 1 Shale (Yoredale | Upper Limestones, Rocks). J^Edgc Coals Series, ^ Gu'btniferous Carboniferous I Lo>\er Limestones. c* Limestone. 1 Limestone. j Lower Lime- Sandstones. Shales, and stone shale. Bur(lle House Lllnc ' 1 v siono. a j r , .) Upper Devonian and Petherwin Lime- W H 2 5* stone. r, a n 5 r Devonian . Middle Devonian Limestone and Coru- S * ? stones. Ojc < ^ Lower Devonian. 288 APPENDIX. TABLE OF BRITISH FORMATIONS. m Ludlow , Wcnlock Llandeilo Tilestone. Upper Ludlow. Aymestry Limestone. Lower Ludlow. Wenlock Limestone. Wenlock Shale, Sandstone, and Flaga ; Woolhope Limestone. Denbighshire Grits, Shales, Slates, and Flags. Tarannon Shale (Pale Slates). Upper Llandovery Rock. (May Hill Sandstone). (Pentamerus Beds). Lower Llandovery Rock. Caradoc or Bala Beds. Upper Llandeilo Flags and Limestone. &c. Tremadoc Slates. fLingula Beds. \ Harlech Grits, &c. g J I Purple Slates and Grits (St. David's). "g ^Cambrian . -JLlanberis Grits and Slates. g I ILongmynd Rocks. r ^ J Red Sandstone and Conglomerate \ (Scotland). Huronian. Laurentian. The above table, it will be seen, has reference to what are called " typical " sections of the different formations that is, to those exposures of rocks which have been most studied and are best known. Hence many of the names of the for- mations and groups are more or less local, as this was the APPENDIX. 289 only available manner of naming the sub-divisions when geology was a young science. It may seem absurd to speak Fig. 173. Illustrations of "Anticlinal" strata. of " Devonian " (or Devonshire) rocks in America, for instance, as we are forced to do by this method of nomenclature ; but, after all, it is not more singular than to call the language spoken in the United States English. The following terms are largely used in every work on geology, even the most elementary, and," as they cannot well be avoided, perhaps it will be desirable to give a short ex- planation of them. STRATUM (from the Latin word meaning Fig. 174. Illustration of " Synclinal " strata. to strew or spread out) means a single bed of rock, sand, gravel, or clay. When rocks, therefore, lie in parallel layers, they are said to be stratified ; and when there is no appear- ance of such arrangement, they are termed unstratified. STRATA is the plural of STRATUM. A geological FORMATION 290 APPENDIX, means an assemblage of rocks which have some character in common, either of age, origin, or composition. Usually such rocks are grouped together into a system by having a great number of fossils common to them. Both in the use of this word, and SYSTEM, however, there is a great deal of looseness. The latter signifies groups of strata which have intimate relations to each other, generally in the order or sequence of their deposition. EPOCH is a word frequently used to express a particular division or period of geological time. It is, therefore, employed as being almost synonymous with "Age" or "Era." By the term CONFORMABLE, is meant that the strata lie in Fig. 175. Illustration of " Dip " of strata. 'parallel order, one above another. When this is not the case, but when one set of strata, for instance, lies on the upturned edges of the lower, the two are said to be UN- CONFORMABLE. Unconformability is generally regarded as a proof of a break in the order of deposition, and therefore of a period of time, sometimes very great, having elapsed in the interval of the formation of the two groups of rocks. By the DIP of a rock is meant the angle or inclination at which the strata slope. This is always measured from the level of the horizon. The opposite of DIP is RISE a word much in use among coal-miners. They both mean the same thing, only DIP has reference to the position of the observer standing at the surface, who sees the rock sloping away from APPENDIX. 291 him whereas when standing, say at the bottom of a coal- pit, and looking at the same bed, he sees it rising. Another frequent word, and one that often causes much trouble to the young geologist, is STRIKE. It means the direction, or line of outcrop, of any stratum. The STRIKE is said to be always at right angles to the dip. The best way of illus- trating the difference is by supposing the reader to be on the roofs of a row of cottages. Then the ridge running in their length would represent STRIKE, or extension, whilst the sloping of the tiles on either hand would illustrate the dip. We have already used the term OUTCROP, and the reader will have little difficulty in understanding what it means. It signifies that part of any inclined stratum of rock which comes to the surface of the ground. Sometimes, if the rock be hard, it thus forms more or less steep cliffs. Hence, whenever a rock thus comes to daylight, it is said to " crop out." With these few words of explanation for the benefit of the young and unsophisticated student, we bid him " God-speed " to a study which cannot fail to give him health and strength, both of body and mind ; or lead him to a wider and broader knowledge of our old world, and of the POWER whose wisdom and love have nursed it from the earliest times 1 ( 293 ) INDEX. Acidaspis, 51. Acrodus, 138. Actinocrimts, 93. jEclimodus, 138. Agates, 17. Age of Reptiles, 132. Aleutian islands, 209. Alum Shales, 128. Alumina, 5. American types, 212. American animals, 210. Amethyst, 17. Ammonites, 141, 142, 113, 141, 145, 157, 183, 187. Amphibia, 104. Amygdaloid, 1. Anauchytes, 183. Annular ia, 111. Anodon, 75, 76. Anodonta, 75. Anonas, 198. Anoplotherium, 200. Anthracotherium, 201. Antrim beds, 214. Appearance of man, 252. Araucarian pines, 130, 101. Archcpgosaurus, 80, 87. Archaeology, 271. Archaopteryx, 104, 105. Arctic flora, 249, 252. Arctic Ice-cap, 215, 221. Arctic mollusca, 244. Arencolites, 31. Argillaceous rocks, 25. Astartes, 225. Asterolepis, 07. Atlantic mud, 179. A try pa, 54, 55. Ancyloceras, 187. Avicula, 145. Aymestry limestones, 43. ISuculites, 188. Bala limestones, 40. liunksia, 213. Lasaltic columns, 214. Basaltic rocks, 40. Basaltic dykes, 214. Bath Oolite, 150. Batrachians, 124. Beaked saurian, 121. Belemnites, 141,145,158, 184, 185. Bcllerophon, 35. Birds' nests, 102. Black-lead, 20. Bovey Tracey lignite, 213. Boulder, 238. Boulder clay, 244, 255. Box-stones, 230. Brachiopods, 33, 71, 91, 144. 294 INDEX. Bracklesham sands, 195. Breccias, 249. Brixham cavern, 265. Brontes, 72. Bronze period, 269. Brown coal, 207. Bryozoa, 225. Buccinum, 233. Bulimina, 170. Bunter sandstone, 116. Cairngorm, 17. Calamites, 81, 83, 84, 104, 105, 107. Calceola, 60. Cambrian rocks, 24. Camels, 219. Camphor-trees, 212. Caradoc sandstones, 46. Carboniferous, 80. Carboniferous limestone, 90, S6. Carboniferous forests, 106. Carcharodon, 202. Cardita, 224. Cassidaria, 225. Casts, 35. Cave Tiger, 235. Cephalaspis, 68. Cephalopoda, 35. Ceratites, 118. CJuzropotamus, 201. Chain-coral, 54. Chalcedony, 17. Chalk, 167, 181, 190. Chalk foraminifera, 167. Cheirotherium , 124. Cheshire meres, 122. Chipped flints, 263. Cidaris, 152, 184. Clay, 193. Claystone porphyry, 5. Cleavage, 25. Clinkstone porphyry, 5. Club-mosses, 57. Clymenia, 62, 72. Coal, 79. Coccoliths, 179. Cockles, 185. Comatula, 138. Compsognathus, 163. Conclusion, 291. Cones, 202. Coniferous trees, 112. Contorted rocks, 27. Coprolites, 229. Coralline crag, 223, 224, 226, 233. Corallines, 49. Coral Eag, 150. Coral-reefs, 53. Cornbrash, 150. Cosmical hypothesis, 2. Crags, 222. Cretaceous formation, 80. Cretaceous sea, 169, 179. Crinoids, 92. Cristellaria, 176, 178. Crystals, 17. Ctenoid fish, 185. Cuttle-fish, 35. Cyathophyttum, 73. Cycads, 161, 162. Cycloid fish, 185. Cyclopteris, 74. Cyprea Europea, 228. Cyprina, 224. Cyrtoceras Murchisoni, 48. Cystideans, 33, 53. Dapedius, 138. Dartmoor granite, 213. Dawn-animalcule, 18. 295 Dead Sea, 120. Dead shells, 173, 174, 177. Deer, 218. Deinosauria, 162. Deinotheria, 218. Deltas, 216. Dendritic crystals, 8, 9. Dentalina, 167, 168. Denudation, 12. Devonian rocks, 62. Dichobune, 201. Dicynodonts , 127. Diluvium, 238. Dirt-beds, 161. Downton sandstones, 48. Dryandroides, 213. Dryopithecus, 218. Dudley strata, 45. Earthquakes, 189. Echinodermata, 183. Emarginula, 228. Encrinites, 117. England joined to continent, 249. English chalk, 168, 169. Elephants, 231, 235, 249. Eocene, 80, 194, 195, 202, 209. Eozoon, 18. Etna, 237. Eucalyptocrinus, 93. Euomphalus, 53. Eurypterus, 66. Evergreen plants, 212. Excess of salt, 121. Extracrinus, 138, 141. Fairy loaves, 183. Fan palms, 213. Fascicularia, 225. Faults, 113, Favosites, 54, 72, 73. Feather-star, 138. Felspar, 3. Felspar porphyry, 5. Fig-trees, 213. Flabellarias, 213. Flabellina, 177, 178. Flint, 17, 180, 181. Flint arrow-head, 264. Flint bands, 180. Flint cores, 266. Flint implements, 260, 261, 265, 267. Flint nodules, 180. Flying lizards, 161. Foldings of rocks, 26. Foot-print impressions, 119. Foot-prints of birds, 125. Foraminifera, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 178. Forest bed, 234, 235, 241. Forest marble, 150. Formation of lakes, 2-51. Fossil animalcuhe, 175. Fossil butterflies, 216. Fossil caddis worms, 216. Fossil corals, 71, 225. Fossil eggs, 163. Fossil feathers, 165. Fossil ferns, 106, 131. Fossil ferns, 211. Fossil flora, 211. Fossil flowers, 211. Fossil fruits, 197. Fossil insects, 216. Fossil Oolitic wood, 160. Fossil pitch, 129. Fossil tree fern, 109. Fossil turtles, 203. 296 INDEX. Four-horned deer, 219. France, Central, strata in, 216. Free-stone, 61. Fresh-water lakes, 215. Frondicularia, 168, 177. Fucoids, 61. Ganoid fishes, 66, 198. Gasteropoda, 35. Gaudryina, 169. Gault, 187. German Ocean, 233, 241. Giraffe, 219. Glacial beds, 232, 255-. Glacial boulders, 239. Glacial period, 194, 239, 259. Glaciers, 242, 244, 245. Globigerina, 173, 174, 176. Glutton, 249. Gneiss, 18. Gold, 57. Goniatites, 90. Granite, 4. Granite of Cornwall, 10. Granite of Scotland, 10. Granite nucleus, 12. Granite bosses, 27. Graptolites, 40, 49, 50. Gravel pit, 254, 272. Gravels, 259. Greek fable, 272. Greenland lignite beds, 214. Greenland ice, 243. Growth of civilisation, 271. Gryphea, 144, 153. Gulf -stream, 245. Gypsum, 119. Gyroceras, 90. Hafted stone celt, 270. Hairy rhinoceros, 249. Hamites, 188. Holy sites, 54. Harlech grits, 30. Headon series, 195. Hearts, 183. Hcliolites, 72. Hipparion, 219. Hippodium, 145. Hippopotamus, 218. Homanolotus, 72. Holoptychim, 68. Hornblende, 3. Horse-tails, 103, 104. Hybodus, 138. Hycenodon, 201. HylcBosaurus, 187. Hymenocaris, 33. Ice action, 249. Icebergs, 243. Iceland lignite beds, 214. Iceland, fossil plants in, 214. Ice-sheet, 250. Ichthyosaurus, 132, 133, 134. Ichthyocrinus, 93. Ideal landscape of Triassic period, 114. Ideal landscape of Oolitic epoch, 147. Ideal landscape of Oolitic epoch, 206. Ideal landscape of Quaternary period, 254. Iguanodon, 187. Illanus, 52. Inferior Oolite, 150. Influence of earth's heat, 23. Irish elk, 250, 251. Iron age, 269, INDEX. 297 Iron-stone, 156. Japanese Islands, 209. Jasper, 17. Jet, 128, 149. Joints, 26. Jordan river, 121. Jura Alps, 165. Kaolin, 4. Kelloway rock, 150. Kent's cavern, 265. Keuper beds, 116, 119. Keuper sea, 121. Kilkenny sandstones, 74. Kimmeridge clay, 150. King-crab, 49. Labyrinthodonts, 86, 124, 125. Lake Dwellings, 269. Lamp-shells, 144. Land ice, 242. Landscape of Carboniferous pe- riod, 78. Last active volcanoes, 214. Laurentian, 17. Lava, 9. Leiodon, 185. Lemming, 219. Lepidodendron, 75, 82, 84, 85, 99, 103. Lepidosteus osseus, 66. Lepidostrobus, 82, 99. Lepidotus, 138. Lcptcena, 55. Liassic formation, 80, 128. Lignite beds, 201, 207, 211. Lily encrinite, 117. Limpet shells, 229. Limestone, 37. Lingula, 33. Lingula flags, 30, 33. Lingula Lewisii, 45, 55. Lituola, 177. Llandeilo flags, 46. London clay, 194, 229. Long-armed monkey, 220. Longmynd rocks, 31. Lower Cambrian, 31, 32. Lower Cretaceous, 188. Lower green sand, 187. Lower Oolite, 150. Lower Silurian, 47. Ludlow beds, 48. Ludlow bone-bed, 57. Lump of clay, 193, 196, 197, 198. Machairodus, 218. Mactra, 230. Magnesian limestone, 115. Magnolias, 213. Mammoth, 248, 263. Man's appearance, 252, 259. Mastodon, 217, 218. Margimdina, 168. Marsupials, 126, 131. May Hill sandstones, 47, 52. Mechanical origin of rocks, 25, 33. Megalichthys, 97. Megalodon, 72. Megalosaurus, 163, 187. Metal lodes, 57. Metamorphic rocks, 18. Meteorological agencies, 38. Mesozoic epoch, 117. Mica, 3. Mica schist, 10. Micraster, 183. Microlestes, 126, 127. Microscopic action, ISO, 181. 298 INDEX. Microscopic structure of fossil wood, 112. of coal, 112. Middle drift, 255. Middle Silurian, 47, 52. Middle Oolite, 150. Minute fossils, 177. Miocene, 80, 206, 208, 210. Miocene forests, 210. Miocene plants, 211. Missing links, 163, 165, 201, 219. Mitres, 202. Moel Tryfaen, 245. Molasse, 209. Monkeys, fossil, 217. Mososaurus, 185, 186. Mountain-chains, 11. Murchisonia, 52. Muschelkalk, 116, 118. Muskdeer, 249. Mussels, 236. Mya, 231, 232. Mylodon, 222. Natica, 228. Nautilus, 53, 141, 143, 202. Neocomian beds, 187. Neolithic implements, 264, 267. Neptunian controversy, 2. Neuropteris, 106. Newer Stone Age, 266. New Red Sandstone, 116. Nipadites, 197. Nodosaria, 167. Norfolk cliffs, 244. Norfolk forest-bed, 234. North Atlantic, 145. Northern drift, 239. Northern shells, 231. Norway spruce pine, 234, 242. Norwich Crag, 223, 230, 234, 241. Nummulites, 195, 196. Obolus, 55. Older Pliocene, 223. Oldhamia, 32. Old Bed Sandstone, 62, 70. Onchus, 69. Oolitic animals, 166. Oolitic period, 80, 149. Oolitic strata, 160. Ophioderpeton, 86. Opossum, 218. Or this, 55. Orthoceratites, 35, 49, 90. Osmunda, 75. Osteolepis, 68, 69. Oxford clay, 150. Oysters, 236. Palaeolithic flint implements, 2G6. Palaeolithic period, 263. Palceoniscus, 98. Palccopteris, 74. Palceopyge, 32. Palaotheria, 198, 199. Palaeozoic brachiopods, 55. Palaeozoic Encrinites, 93. Paludina, 153, 155. Paradoxides, 34. Paramoudra, 182. Parkia, 65. Pebbles, 256. Pecopteris, 109. Pecten, 53. Pectunculus, 224, 228. Pegmatite, 5. Pentacrinus, 139. Pentamerus, 53, 54, 55, Pentremites, 95, INDEX. 299 Percolation, 35. Permian breccias, 115. Permian formation, 115. Petroleum, 41. Phillipsia, 92. Phlebopteris, 156. Phosphates, 21. Phosphate of lime, 183. Phosphatic nodules, 229. Phragmacones, 184. Piece of chalk, 1G7. Pilton group, 71. Pitchstone, 8. Placoid fishes, G9. Plagiostoma, 145. Planorbis, 153, 230. Platycrinus, 83. Pleistocene, 231. Plesiosaurns, 132, 135. Pliocene, 80, 215, 223, 220, 236, 237. Pliopithecu*, 218. Plumbago, 20. Plutonic controversy, 2. Polished Celts, 209. Polypothecia, 180, 181. Porphyrine (artificial), 9. Porphyry, 5. Portland Stone, 150. Pot- stones, 182. Primary rocks, 15. Primitive rocks, 0. Producta, 54, 115. Proteacea, 213. Protogine, 5. Protozoic rocks, 28. Psiloplnjton, 75. Psychometry, 59. Pterichthys, 67, 68. Pterodactyls, 132, 136, 137, 155. Pterophyllwn, 131. Pterygotus, 65. Purbeck marble, 146, 153, 159. Purbeck series, 150. Pyrula, 225. Pyrulina, 168. Quartz, 3, 14. Quartz crystals, 7. Quartzite, 16. Quaternary, 80. Rain-drop pittings, 119. Red Crag, 223, 229, 230, 241. Eed Crag, shells of, 229. Reindeer, 249, 266. Reindeer period, 266. Reptile-like birds, 164. Restored Belemnite, 185. Restored Calamites, 107. Restored Lepidodendron, 99. Rhsetic formation, 126. Rhinoceros, 234, 236, 249. RJiodocrinus t 93. lihynchonella, 54, 145, 184. RhynchosdUTUB, 124. Ripple-marks, 31, 32, 89, 119, 154. River-gravels, 255. Rostellaria, 202. Rock-oil, 41. Rock-salt, 115. Rosalind, 172. Rotalina, 173, 175, 177. Sagenaria, 75. Sagrina, 174. Sahara sea, 251. Salisburia, 215. Sandstone, 58. Scales of Carboniferous fish, 98. 300 INDEX. Scapltitcs, 188. Sea-urchins, 183. Section of fossil wood, 103. Segregation of metals, 57. of minerals, 57. Semnopithecus, 218. Sequoias, 213. Sewalik hills, deposit of, 219. Sharks, 185, 203. Sicilian beds, 236. Sigillaria, 84, 85, 102, 103. Silica, 3, 17, 179, 181. Silurian rocks, 39. limestones, 41, 45. Single corals, 95. Siphuncle, 143. SivatJierium, 219. Slate rocks, 24. Smilax, 212. Spicuhe, 182. Spin/era, 54, 55, 72, 91, 144. Spirorbis, 84. Spondylus, 185. Stalactite, 265. Stalagmite, 265. Star-fish, 53. Stauria, 71. Stone Celt, 270. Stonesfield slate, 150, 163. Stringocephalus, 72. Stromatopora, 72. Strcphomena, 54, 55. Structure of Pentremiies, 96. Sub-tropical climate, 190. Suffolk strata, 223. Sun-cracks, 32, 89, 119, 120. Sun-corals, 72. Tapiroid animals, 199. Tapirs, 218. Tarannon shales, 47. Taxocrimts, 93. Teeth of Carboniferous fish, 98. Tettina Balthica, 244. Tellina crassa, 228. Temmchinus, 224. Temperature of Miocene Period, 209. Terebella, 202. Terebratula, 54, 145, 151, 184. Terraces, 255. Terraced hills, 256, 257. Tertiary epoch,. 191, 194. Textularia, 169. Theca, 34. Thickness of lias, 130. Thunder-bolts, 144, 145, 158, 184. Topaz, 17. Tortoise, huge, 219. Transition rocks, 18. Transverse section of calamite, 83. Transverse section of fruit of calamite, 105. Tree-apes, 218. Tree-ferns, 105. Trias, 116. Triassic Period, 114. Trigonia, 154. Trilobites, 34, 40, 41, 49, 51, 72. Trogontherium, 235. Truncatulina, 171. Turrilites, 188. TurriteUa, 195. Turtles, 203. Typhis, 202. Unconformable rocks, 22, 119. Upper Crag, 233. Upper Eocene, 204. Upper green sand, 188. INDEX. 301 Upper Oolite, 150. Upper Silurian, 48, 53, 54. Valley-gravels, 255, 263. Vancouver's Island, 209. Verneuilina, 170. Vertebrata, 54. Vertical section of calamite, 81. Vertical section of fruit of cala- mite, 104. Volutes, 202, 226. Wart-hogs, 218. Wealden strata, 186, 187. Wenlock group, 48. Wenlock limestones, 42, 48. Wentle-traps, 230. White whelk, 233. Woolhope beds, 48.' Woolly-haired elephant, 263. Woolly-haired rhinoceros, 263. Worm-tracks, 32. Zamias, 161. Zaplirentis, 72. THE END. CNWIK BROTHERS, LIMITED, PRINTERS, WOKING AND LONDON. RETURN EARTH SCIENCES LIBRARY TO -* 230 McCone Hall 642-2997 LOAN PERIOD 1 1 MONTH 2 3 4 5 6 ALL BOOKS MAY BE RECALLED AFTER 7 DAYS Books needed for class reserve are subject to immediate recall DUE AS STAMPED BELOW FORM NO. DD8 UNIVERSITY OF CALIFORNIA, BERKELEY BERKELEY, CA 94720 f