r;.^i;wK VWi^i .v^;^:a;^^^ "V^ :<^.m^^f'^A^'li ;^;«j :^>^^^ j^. ^■^^: ^ J^ ■fr, .■;'W^ ^Wj>^V'V '^wvvvi;^;;.^ ^>:)»:> :> § 3^ >> LIBRARY OF I >■ 3.j> :>> x> ^' jr>; > :oi>>3 > X>> > ) -^> 2j> ■:> >'Z> :>x : :5> j>3> >^>^.. _!> V:>. ;'2) 7> ' ' — C^ 3» r^ 3I> k.'iS^ J , 0^ ^ l") THE ENTOMOLOGISrS TEXT BOOK. c//^/" fa^Sja//< J^A-'/'/fc/f/'/ff 0/fAAo>/v/K P/A/Tr'?/r/r^y^/??y^/f^'/^ca/ '^-^//i/ i]^^ iVia^^ iCkirui/ 1838. THE ENTOMOLOGIST'S TEXT BOOK; AN INTRODUCTION THE NATURAL HISTORY, STRUCTURE, PHYSIOLOGY, AND CLASSIFICATION finserts. INCLUDING THE CRUSTACEA AND ARACHNIDA. BY J. 0. WESTWOOD, F.L.S., 6KCRKTART TO THK KNTOMOLOG ICAI. SOCIETY OF I.ONOON, HON. MEM. SOC. NAT. HIST . QUKBEC, MO«CO\r, LUND, LILLE, MACalTirS, ENT. SOC. PARIi, ETC. LONDON: WM. S. ORR AND CO., AMEN CORNER, PATERNOSTER ROW. MDCC'CXXXVIIt. ■W. I,. CRAVKS AND CO., PRINTEH«, LONDON. PREFACE. The present Volume owes its existence to a desire on the part of the Publisher of the British Cyclopaedia of Natural History, that the leading Entomological articles which appeared in that work from my pen should be collected, so as to form a general sketch of the outhnes of the science to which they relate. The object of that work was essentially popular, and it was written more espe- cially for the general reader. It was necessary, therefore, not only that the various articles should be divested, as much as pos- sible, of technicahty, but also that the attention of the reader should be constantly directed to the uses of organs of which the descriptions were laid before him ; thus not only imparting to the subject a greater degree of interest, than though bare descriptions and technicalities had been given ; but, which was of far higher importance, proving that in all the various formations exliibited by these tribes of animals, an AU-wise Creator had bestowed those various structures for the performance, in the most satisfactory manner, of their different functions. In re-publishing these various articles, I have met with one difficulty, for which I hope due allowance ^^111 be made by the reader. In an Encyclopsedia, the most ample, and generally the most interesting details, are confined to those articles treating of genera and species, to which constant reference is made for the illustration of the more general articles. I have endeavoured, in some degree, to make up for this deficiency, by the introduction of the various orders of insects. These two circumstances vrill, I trust, be considered a sufficient reason for the omission of much valuable matter relative to the anatomy, not only of the Crustacea and Arachnida, but also of the true Insects, of which such ample details have, in these few late IV PREFACE. years, been given to the world by Strauss-Durckheim, Leon Dufour, Kirby, Audouin, Burmeister, Newport, and others. All that I dare affirm of this volume is, that it will be found to contain a concise introduction to the Elements of Entomology, brought doMH to the present state of the science ; in which, indeed, many interesting details are necessarily omitted, which the student who is disposed to enter more deeply into the subject must seek for in the works of Kirby and Spence, Burmeister, and others. It has ever been my wish to instil into the minds of those who feel an interest in the science, the idea that the mere collecting of spe- cimens, or of attempting their classification, could not be compared, in an intellectual point of view, or with reference to the amount of pleasure derivable from the subject, with the investigation of habits of the animals, and the variations in their structures depen- dent thereon. To those conversant with Entomological Literature, it was evident that there existed the want of a work like the pre- sent, which should convey the modern elements of the science in as popular a form as possible ; and it appeared to me, that this work might be so written, as to be the means of extending this leading principle of philosophical zoology. To make the present volume more acceptable to the general reader, several plates of insects have been added, not contained in the British Cyclopaedia, and which, together with the very numer- ous wood illustrations, will render the subject more generally in- telligible than though double the space had been devoted to mere descriptions. These figures, together with those in the body of the book, are from my own pencil, being in almost every instance original. I have added, for facility of reference, an alphabetical index of the anatomical parts, and an arranged list of the figures of in- sects scattered through the body of the work. J. 0. W. Hammersmith, October, 1838, CONTENTS. INTRODUCTION. ExTOMOLOGY defined Extent of subject Variety of habits Grounds of superiority Wisdom of Creation in insects especially shown Benefits and Injuries from Insects .... Insects used as food, &c. . Use of insects in the general eco nomy of nature Obnoxious powers of insects Plague of flies ftlusquito — Harvest bug Insects attacking man, &c. furniture, provisions growing crops trees Remedies asrainst insects . Modes of Research Amateur collector — Collecting apparatus ... Ravages of Anthreni . Nomenclaturist ... Generalized views of Entomo logy requisite ... Investigation of the names of in sects .... Out-door Entomologist, and ob sener of nature PAGE 3 4 7 8 11 11 12 15 16 17 19 20 22 23 24 27 28 29 31 32 33 35 Advantages of studying from the life 39 Structure dependent upon habits 40 Character of the true naturalist 45 Relations of Insects . . 45 Affinity and analogy . . .47 Instances of these relations . 49 Pi'oof of a system . . .50 Difficulties of the natural sys- tem 51 Number of insect species . . 53 Classification and Nomen- clature OF Insects . . 55 Uses of nomenclature . . 59 Series of nature .... 60 Constancy of species . . .62 Varieties 63 Specific names . - . .65 Generic names . . . .67 Rise of Entomological Sci- ence 67 Aristotle and the ancients . . 68 Revival of letters . . .69 Redi, Swammerdam, &c. . . 70 Linnfeus 71 Fabricius— Latreille . . .72 Nature of modern researches . 73 British authors . . . .74 Entomological Societies . . 75 CHAPTER I. ON THE EXTENT AND APPLICATION OF THE TERM INSECT. Leadin? characters of insects . 76 The Linnsan sub-kingdom re- tained .... Di\ision into classes . . 77 . 79 CHAPTER II. Class I.— Crustacea. History of class . Relations of Crustacea Characters .... Topical organization . Nomenclatm-e of organs . Senses .... 80 81 82 83 84 85 Moulting .... Metamorphoses . Distribution into orders . Order 1.— Decapoda Sub-order Brachyura Characters . . 87 . SI) . 92 . 93 94 95 VI Distribution Habits of crabs . Sub-order Macrura Habits of hermit crabs Other Macrura . Cray-fish Order 2. — Stomapoda CONTENTS. FAGE FAOE . 96 Order 3. — Amphipoda . 105 . 98 Order 4. — L^MODIPODA . . 107 . 99 Order 5. — ISOPODA . . 110 . 100 Order 6. — Branchiopoda . 113 . 101 Order 7. — P^CILOPODA . . 119 . 102 Order 8. — Trilobita . 122 . 103 CHAPTER III. Class II.— Arachnida. History of class . 125 Characters . 126 Senses . 127 Circulation . 129 Classification . 130 Order 1.— Dimerosom> lTA . 132 Webs of spiders . 133 Reputed bird-killing spiders Tai-antula Order 2. — Polymerosomata Scorpion Order Z. — Adelarthrosomata 145 Order 4. — Monomerosomata 146 Order 5. — Podosomata . . 148 139 140 143 144 History of class Arrangement Order 1.— Chiloqnatha CHAPTER IV. Class III.— Ametabola. . 150 1 Orrfer 2.— Chilopoda . 151 I Order 3. — Thysanura . 151 I Order 4.— Anoplura CHAPTER V. 154 157 159 Characters Class IV.— Ptilota, or AVixged Insects . 163 section I. On the principles which regulate the metamorphoses of insects 164 Views of Swammerdam, Herold, and Kirby .... 165 Ditto of Virey .... 166 SECTION II. The peculiarities exhibited by in- sects in their passage to the perfect state ... 169 Various stages of developement 170 Sub-section \.— The Egg . .171 Eggs deposited in nests . 172 Number and form of eggs . 174 Instinct of female in providing for and protecting her young 177 Sub-section 2.— The Larva . 179 Uniformity of structure . 180 Monomorphous larvae . . 181 Heteromorphous larvae . . 182 Head of larva, & its appendages 183 185 188 189 192 194 195 201 Other segments of lan'^ae Analogies of larv^ae Voracity of larvae . Colours and growth of larvae Sub-section 3.— The Pupa Varieties of the pupa Latreille's arrangement from metamorphoses . Newman's ditto . . .202 Observations thereon . . 203 Metamorphosis inchoata . 204 Metamorphosis dimidiata . 205 Metamorphosis perfecta . 206 Chrysalides .... 208 Segments of pupae . . .211 Arrangement of Umbs in pupae 212 Duration of pupa state . . 215 Cocoons 217 Cocoon of silk-worm, &c. . 219 Escape of imago from pupa . 222 Anomalous deviations . . 224 .SECTION III. The general structure of insects, as especially exhibited in their perfect state . . . 225 Sub-section 1. — External Ana- tomy 225 Segments of the body . . 227 A, The Head . . . .229 Clypeus 232 Head organs .... 232 Composite eyes . . . 234 Ocelli 237 Antennae .... 238 Mouth 243 Varieties of mouth . . 245 Labrum 249 Mandibles . . . .250 MaxiUae 252 CONTENTS. VII FAOK Labium and Mentum . . 255 B, The Thorax . . .260 Its division into three segments 262 Upper and under surface . 265 Prothorax . . . .267 Mesothorax .... 269 Metathorax . . . .272 Wings 274 (o) Membranaceous wings . 275 Markings of wings . . 278 {ft)Tegmina . . . .281 (c) Hemelytra . . .282 (rf) Elytra . . . .282 (e) Halteres . . . .284 (/) Pseudhalteres . . .285 Legs 286 c, The Abdomen ... 289 Sub-sec. 2. --Internal Anatomy A, The nervous system . . 294 Want of sense of pain in insects 297 Senses of insects . . . 299 {a) Sense of sight ... 300 (b) Sense of hearing . . 303 (c) Sense of smell . Id) Sense of taste . (e) Sense of touch . B, The digestive system . c, The circulatorA- system D, The respiratory system E, The muscular system . F, The generative system . SECTION IV. Physiology and instinct of in- sects Instinct Instinct for perpetuation of spe- cies Instinct for self-presers'ation . Modes of defence and attack . SECTION V. Classification of insects Linnaean arrangement Other arrangements . Latreille's last arrangement CHAPTER VI. ILLUSTRATIONS OF THE ORDERS OF PTILOTA. Order 1. — Coleoptera . . 335 Characters , . . .336 Habits, &c 341 Latreille's arrangement . 344 Order 2. — Euplexoptera . 346 Characters — Habits . . 347 Order 3. — Orthoptera . . 349 Characters — Habits . . 350 Arrangement .... 352 Order 4.— Thysanoptera . 359 Order 5. — Hemipteba . . 360 Characters . . . .361 Arrangement .... 362 Order 6, — Neuroptera . , 364 Characters — Metamorphoses 366 Arrangement .... 369 Order 7.— Tbichoptera . . 369 Order 8. — Hymenoptera Characters — Habits Relations . . . . Classitication . . . . Order 9. — Lepidoptera . Characters — Metamoi-phoses Arrangement . . . . Order 10. — Strepsiptera Order 11. — Diptera Characters — Habits Metamorphoses Arrangement Order 12. — Aphaniptera 306 308 309 310 312 314 316 318 318 319 320 322 324 329 329 330 332 371 376 380 387 389 397 403 407 411 414 417 420 421 Alphabetical List of the chief En- tomological Writers . . 423 Anatomical Index , . . 431 LIST OF FIGURES OF INSECTS, (excluding thb dissections,) ARRANGED ACCORDING TO THE PRECEDING CLASSIFICATION. Class I.— Crustacea. Class II.— Arachnida. Carcinus Maenas (common small At^-pus Sulzeri .... 126 edible crab) . 95 Argyroneta aquatica 38 Zoea 90 Epeira diadema 136 Caprella Phasma 109 Armadillo vulgaris . 111 Class III. — Ametabola. Artemia salina . 118 Glomeris marginatus 153 Argulus foliaceus 121 Lithobius forcipatus 155 Asaphus extensus . 123 G€ophilus longicornis 155 Vlll CONTENTS. lulus . Pediculus humanus PAGK 197 160 Class IV.— Ptilota. ORDER I. — COLEOPTERA. Carabus clathratus . Brachinus crepitans . Dyticus marginalis, and larva Goerius olens Lampyris noctiluca (g:low-wonn), male and female Anobium striatum Necrophorus vespillo Dynastes Hercules . Scarabaeus iEgyptiorum Geotrupes stercoi-arius Chrysina macropa Cetoniaaurata . Blaps mortisa^a Cantharis vesicatoria Attelabus curculionoides Apoderus avellanae Rh^nichites cavifrons Apion flavipes ? Balaninus nucum Tomicus typo^aphus Tracks of ditto Hylur^us piniperda . Acanthocinus speculifer Cerambyx moschatus Chrysomela populi . Haltica nemorum Cassida \aridis ORDER III. — ORTHOPTERA. Blatta orientalis Mantis religiosa Bacteria fragilis Gryllotalpa vulgaris Gryllus viridissimus Ditto, lan'a and pupa ORDER V. — HEMIPTERA. Velia currens Fulgora laternaria Centrotus globularis cruciatus Aphrophora spumaria ORDER VI. — NEUROPTERA. iEshna? 366 .Libellula pupae . . . 323 Agrion puella? . . . 364 Ephemera vulgata . . .198 Myrmeleon formicarium . 324 pitfall of larva . 323 Termes in different states . 367 nests . . . .319 36 325 187 292 303 305 173 7 15 335 288 340 336 13 231 231 231 25 345 24 24 24 242 307 200 12 9 354 355 356 357 358 197 206 303 363 363 328 Termes, section of nest Atropos pulsatorius 320 368 ORDER VII. — TRICHOPTERA. Phryganea grandis ? . . 370 ORDER VIII. — HYMENOPTERA. Pimpla manifestator . . 378 Apliidius Rosae . . . . 388 Cynips quercus folii . ' . . 378 tinctoria . . .14 Callimome bedegnaris . . 214 Polyergus rufescens . . 388 Formica fusca .... 388 Atta cephalotes ... 22 Ammophila sabulosa . . 377 Polistes gallica, nest . .381 Vespa germanica, nest . . 389 Anthophora retusa ... 33 Bombus lapidarius, and nest . 384 Andrena nigro-aenea . . 389 Apis mellifica (hive-bee, male, fe- male, and neuter) . . 376 Ditto, larva and pupa . . 379 Apiary 321 Cells of bees . . . .321 Mouth of bee .... 380 Sting of bee .... 375 ORDER IX. — LEPIDOPTERA. Vanessa urticae . . . 222 Hipparchia pamphilus . . 199 Acherontia Atropos . . 21 Sphinx ligustri, larva . . 398 Saturnia pavonia, cocoon . 9 Promethea . . .401 caterpillar, &c. . . 403 Arctia villica .... 390 Abraxas grossulariata . . 399 Ourapteryx sambucaria, lars-a 398 ORDER X. — STREPSIPTERA. Stylops Dalii .... 409 ORDER XI. — DIPTERA. Culex pipiens ... 16, 223 Chironomus . . .417 Cecidomyia tritici and destructor 23 200 33 22 20 20 Stratiomys chamaeleon EristaUs Piophila casei . . . . Gasterophilus equi . haemorrhoidalis ORDER XII. — APHANIPTERA. Pulex irritans 421 Collecting apparatus 29 EXPLANATION OF THE COLOURED PLATES. Plate I.— Page 80. Class Crustacea.— Order Decapoda. Gonoplax angnlata, young', var. Order Isopoda. Limnoria terebrans, magnified. Arcturus longicornis, female, rather magnified. Class Arachxida. — Order Dimerosomata. Dysdera er^'thrina. Order Podosomata. Pycnogonum Balaenarum. Class Auetaboul.— Order Chilognatha. lulus terrestris. Order Thysanura. Petrobius maritimus. Order Anoplura. Hsematopinus Suis. Plate II.— Page 335. Class Ptilota. — Order Coleoptera. Cicindela hybrida, natural length one-half of an Miscodera Arctica, „ one-fourth Orectochilus villosus, „ one-fourth Agabus serricornis, „ one-half Spercheus emarginatus, „ one-fourth Abdera, four-fasciata, „ one-sixth Clythra Hordei ? „ one-sixth Saperda Carcharias . . natural size. nch. : EXPLANATION OF THE COLOURED PLATES. Plate III.— Page 349. Order Orthoptera. Aclieta carapestris, natural size. Order Hemiptera. Chorosoma miriformis, natural length one-third of an inch. Centrotus Genistae, „ one-sixth „ Order Neuroptera. Chrysopa perla, natural size. Order Hymenoptera. Eumesius (Euceros) crassicornis, natural length one-third of an inch. TengyTa Sanvitali, „ one-third „ Order Diptera. Ochthera mantis, natural length one-sixth of an inch. Plate IV.— Page 389. Order Lepidoptera. Butterflies. Papilio Machaon and lan'a. I Polyommatus Arion. PapiUo Podalirius. | Artaxerxes. Lycaena Chryseis. [ Cynthia Orythia, vox.— Title-page. Plate V. — Frontispiece. Moths. Deilephila Euphorbias. I Abraxa grossulariata. Sesia Fuciformis. | Adela De Geerella. Zeuzaera ^sculi. I Argyrosetia Brockella. Chariclea Delphinii. 1 ERRATA. P. 155, fig. a, Lithobms forcipatus. — 288, fig. — The insect here figured is the Chrysina macropa (Scarabceus macropus, Francillon). ITie male of Chrysophora chrysochlora (Latr.) is similarly organized. — 292, fig. Goerius olens. — 312, fig. — The figure in this page, reduced from Lyonnet, shows the circidatory system of the caterpillar of the goat-moth, — the large dorsal vessel, with angulated sides, extending along the back. — 389, fig. Andrena n/gro-tenea. P R (E M I U M. " Full Nature swarms with life ; one wond'rous mass Of animals, or atotm organized, Waiting the vital breath, when Parent Heaven Shall bid his spirit flow. * * * * Through subterranean cells, Where searching sunbeams scarce can find a way, Earth animated heaves. The flowery leaf Wants not its soft inhabitants. Secure Within its winding citadel, the stone Holds multitudes. But chief the forest boughs, That dance unnimiber'd to the playful breeze. The downy orchard, and the melting pulp Of mellow fniit, the nameless nations feed Of evanescent insects. "WTiere the pool Stands mantled o'er with green, invisible, Amid the floating verdure, millions stray : * * * Nor is the stream Of purest crystal, nor the lucid air. Though one transparent vacancy it seems. Void of their unseen people. * * * * * These, conceal'd By the kind art of forming Heaven, escape The grosser eye of man. * * Let no presuming impious railer tax Creative wisdom, as if aught was form'd In vain, or not for admirable ends. Shall little haughty Ignorance pronounce His works unwise, of which the smallest part Exceeds the narrow vision of her mind? PROCEMIUM. As if upon a full proportion'd dome, On swelling columns heaved, the pride of art, A critic fly, whose feeble ray scarce spreads An inch around, with blind presumption bold Should dare to tax the structure of the whole. And lives the man whose universal eye Has swept at once the unbounded scheme of thing^s, Mark'd their dependence so, and firm accord, As with unfaltering accent to conclude That this availeth nought ? Has any seen The mighty chain of beings, lessening down From Infinite Perfection to the brink Of dreary nothing, desolate abyss ! From which astonish'd thought, recoiling, turns ? Till then alone let zealous praise ascend. And hymns of holy wonder, to that Power Wliose wisdom shines as lovely on our minds As on our smiling eyes his servant Sun." Thomson. THE ENTOMOLOGISTS TEXT-BOOK. INTRODUCTION. Entomology is that branch of zoology which treats of the insect tribes, as restricted by the knowledge obtained by the elaborate researches of modern comparative ana- tomists. The term is derived from two Greek words, entomon, an insect, and logos, a discourse ; the former word, as well as the sjnonymous Latin word, insectum, which we have anglicised into insect, being themselves compounded of other words, signifHing a cutting or dividing into sections or articidations, whence, in fact, we arrive at one of the great characteristics of these tribes, namely, the articidated struc- ture of the external parts of the bod} , which, being of a corneous texture, serve as supports for the muscles and other internal organs, just as the internal vertebrae of the higher animals support the same parts ; so that in this class of the invertebrated animals the external covering may pro- perly be regarded as the skeleton. Now, this character, joined to those derived from the respu-atory, nerv^ous, and locomotive systems, tends to separate the true articulated animals from a great number of other smaU creatures, with which, under the common name of insects, they ai-e classed even in some of the latest popular compendiums of natural 4 INTRODUCTION. history which have issued from the press, in which the leech and snail, together with many of the still lower animals, are introduced, without even a sectional note of distinction, amongst insects. If we look around, on every side, in every place, and in every season, we behold the immense profusion with which nature has scattered the objects of our present meditation. The earth, the water, and the air, teem with insect inhabit- ants ; every vegetable supports numerous colonies ; the di- minutive fungus and the gigantic oak are ahke subject to their attacks ; and as a proof of the vast extent of the series it may be added, that Saint Pierre tells us, that several hun- di*ed different species of insects visited a small rose-tree placed in the window of his study, whilst a single forest tree is the abode of numerous tribes and families. In like man- ner they cease not in their attacks upon animal matter, both in a dead and living state ; and man himself, the lord of all, is not exempt from annoyances from them. How necessary, then, from the insurmountable difficulty resulting from the almost infinite number of these creatures, is it to bespeak the indulgence of the reader in attempting to lay before him, in as concise a manner as possible, a sketch of the insect world. It is not difficult to imagine the painful nature of the researches necessary for obtaining a knowledge of the internal anatomy and other pecuharities of creatm-es, of which by far the greater portion do not exceed an inch in length. And here it is that we, in the most especial man- ner, discover the invaluable worth of the microscope, that surprising instrument, by which the minute wonders of the creation are brought as ^^vidly before the eye of the observer, as are the wonders of the celestial sphere by that other philosophical wonder, the telescope. These instru- ments are now, it is true, no novelties ; but we know no more striking instances in which the powers of the EXTENDED NATURE OF OBSERVATIONS. D mind have worked a victory over nature. Speak of the powers of the steam-engine, and the many hundi-ed times by which the manual forces of the human frame are increased by its operations — and what is this in comparison with the tens of thousands of times to which the ordinary size of the meanest insect is increased by the assistance of the microscope? Still, the continued employment of this instrument is a painful operation, increased a thousand fold by the minuteness of the objects, and the extent to which it is necessary to carry the investigation of them. Look at the unwearied laboiu-s of Lyonnet, which were for years devoted to the anatomical examination of a single insect; or at those of Strauss-Dm'ckheim, whose memoir upon the cockchafer exhibits almost an equal endm-ance of observation. If, moreover, we consider that not only does an insect combine mthin itself the systems of respii'a- tion, circulation, digestion, secretion, and sensation analo- gous to those of the higher animals, but also that, owing to the remarkable circumstance that the majority of these ani- mals undergo a series of transformations, whereby these sys- tems are completely altered several times in their progress to the perfect state, it is essential to extend om* observations to every period of the life of the animal, before we can arrive at a perfect knowledge of its structiu-e, so as to enable us to form a proper estimate of its comparative anatomy ; we can- not, therefore, but admit that the difficulties attending the labours of the entomologist are not fewer than those in any other department of zoology ; difficulties which, from their very natiu-e, cannot cease to arouse the attention of the de- voted admirer of the Creation. And hence arises the necessity of our ha%'ing recourse to the labom-s of our predecessors in the vast field opened to us, and in the works of Swammerdam and Lyonnet, De Geer and Reaumur, Latreille and Kirby, b3 n INTRODUCTION. we find the materials, not for a short essay, as this must be at its greatest extent, but for volumes upon volumes. Of all the classes of zoology, then, that of insects is the most numerous, the most beautiful, and the most varied ; and yet it cannot be denied that no portion of the science presents, to those who are ignorant of its merits, so many apparent points of repugnance ; but which, nevertheless, so much captivates the attention the more its merits are ex- amined. It is, indeed, for those who undertake its investi- gation, an unceasing source of instruction and of pleasure, open to all, requiring not, like the study of quatbupeds or birds, great pecuniary sacrifices in the collection of mate- rials, but yet possessing for every observer a still unopened mine of knowledge, even in the very commonest species. Volumes have been -wTitten upon the bee ; but still how many wonders of the hive remain unexplained ? The domestic fly swarms in every apartment, and yet how many points in its economy are uninvestigated ? And, which is not less pecu- liar and interesting to the student of the insect world, he may pursue his observations \\ithout pain to the objects of his research ; he may watch them at their occupations, ob- serve their manoeuvres, and contemplate the beautiful har- mony which exists between their organization and their economy, and leave the contemplation " a wiser and a better man." Here he will find life in its widest extent ; sensation and motion are here bestowed to a degree even far exceethng that of the higher animals ; and it is this which constitutes one of the greatest charms of the pursuits of the entomolo- gist. The botanist may boast of the splendoiu* of his flowers, the conchologist may glory in the beauty of his shells, and the ornithologist in the interesting economy of his bu'ds; but the entomologist can do more. The objects of his pursuit are not less splenchd than flowers ; indeed, what flower can vie with the brilhant butterflies of South America? GREAT VARIETY OF HABITS. 7 Neither are they less beautiful than the most beautiful shells — for what shells can equal the splendid coatings of the Chrysididce, or with the extraordinary forms of the Dy- nastidcef — Neither are they inferior to the feathered tribes in Dynastes Hercules (Brazil), one-third of the natviral length. their varied economy, whilst the very circumstance of their infinite numbers and ubiquity renders their observation a ' matter of comparative facihty. If we notice them with refer- ence to the latter peculiarity (that of their varied economy), we find them occupied in works as varied as those of the most consummate mechanic and artist. Here we find one suspending itself by a series of mechanical motions, by one extremity of the body, whilst others keep themselves from falling dm'ing their state of inactiAity, by passing a cord round the middle of the body ; here some construct, for the like purpose, a bed of the finest silk, whilst others, with the greatest ingenuity, form theu* domicile of other and very different materials, varying in the several species, whose economy is consequently difi'erent. Some unite to form a common lodging, whilst others separately incase them- selves in a coat of wool as soon as they are born. In many instances the patient care of the female in the construction of her nest, and in the preservation of her offspring, is not sm-passed by the highest amongst animals. In all these things. y INTRODUCTION. and in the infinite diversity of means exhibited by insects tend- ing to one common end — the preservation of each — the supre- macy and wisdom of a Di^^e Intelhgence, — creating all things, preser^ing all things, directing all things, — are so pre-eminently conspicuous, that it is impossible, even whilst papng but the shghtest degree of attention to such things, to overlook the subhmity of the science, or not to be filled with the most profound respect for the all-powerful wisdom and goodness of the Creator, and, even in the midst of the most profound grief, it is impossible to contemplate these wonders of the creation without an assuagement of our pain. If, moreover, we would institute a comparison bet\^'een the objects of our present contemplation, and those of the higher ranks of nature, we shall find here assembled all those strik- ing pecidiarities which abound in the latter ; the piercing eye of the lynx and the falcon, the hard shield of the ai'ma- dillo, the splendid tail of the peacock, the imposing horns of the stag, the swiftness of the antelope, the fecundity of the hare, the architectural powers of the beaver, the cUmbing powers of the squirrel, the gambols of the monkey, the swimming of the frog, the bmTO\^Tag of the mole, and the leaping of the kangaroo ; all these things are found amongst insects, and often, indeed, in a redoubled degree. The eye of the fly, with its thousands of lenses, the horns of the stag beetle and djmastes, the splendour of the scales upon the diamond beetle, the hard covering of the beetles (whence even theu* ordinal name, Coleoptera, \^■ings in a case), the admirably constructed works of the hive, the maternal cares of the spider, which guards its bundle of eggs with inces- sant cai'C, carrj-ing them about vdth. it beneath its body; the ingenuity of the cocoon * of the emperor moth, which * The cocoon of this motli is of a brown colour, and shaped somewhat like a flask. It is composed of a solid tissue of layers of silk, almost the texture of parchment ; but at the narrow end it is composed of a scries STRUCTURE OF COCOON OK EMPEROR MOTH. 9 is constructed mtli an elastic aperture, preventing the en- trance of enemies, but allowing exit to the inhabitant; the numberless progeny of the aphis, the powerful flight of the locust, the leap of the elater and grasshopper, the brilliant Hght of the glow-worm, the instinct of the sexton-beetles {Necrophorus), the mottled jacket of the lan-a of the clothes-moth, formed of different coloured wool, or the excrementitious covering of the larva of the Cassida, the frothy abode of the Cercopis, the abandoned Cassida viridis in its different states. shell inhabited by the hermit crab, and the extraordinary gall residences of the Cynipidaj all these, and a thousand other not less interesting cu'cumstances exhibited, and to of loosely attached longitudinal threads, conver^ng like so many bristles to a blunt point, in the middle of which is a circular opening, through which the moth makes its es- cape, the threads readily yield- ing to pressure from within, and acting somewhat upon the prin- ciple of the wires of the opening to a rat-trap, or the willow cricks of an eel-trunk. In order, how- ever, to guard against the danger which might arise from the open- ing permitting the ingress of ich- neumons or other enemies, the caterpillar constructs within the funnel-shaped mouth a second funnel formed of a similar series of threads converging to a point, without the smallest opening being left, and its arched structure rendering it im- Chrysalis and section of the cocoon of the Em- peror Moth, showing-, a. The internal dome — b, The external aperture. 10 INTRODUCTION. be exhibited more at detail in our pages, cannot fail to con- vince the reader that the class of insects does not possess fewer claims to his attention than any other of the classes of nature. The continued action which insects exercise upon the other productions of natm-e (and I may mention, in pass- ing, as a most conclusive evidence of such action, that the island of Grenada is now reduced to a ruinous state owing to the attacks of the diminutive cane-fly upon the canes, hav- ing extended nearly throughout the island), the insurmount- able power of these enemies, o\\ing to their minuteness, the injm'ies which they inflict upon our possessions, animal and vegetable ; the benefits arising from many of them, their ex- traordinary forms and transformations, rivalling the most striking creations of fable, the complexit}'^ of their organiza- tion, external and internal, their inconceivable industry in • the construction of their nests, and the foresight which they manifest in their self-defence, all teach us that Entomology is well worthy of the attention of the observer of nature. But it will be said, why devote our attention to objects so minute? We reply, if the colossal alone be worthy of notice, search elsewhere for the objects of yom- notice, for here the objects are so small, that the full stop at the termi- nation of this sentence is much larger than many of the species. But, to the eye of philosophy, what matters colossal penetrable to the most violent efforts of any external enemy, whilst it yields to the slightest pressure from within, and. allows the egress of the moth with the utmost facility, immediately resuming its former appear- ance, so that it is impossible at first to conceive how it is that the moth can have made its escape from an entire cocoon. Meinecken has also suggested that the pressure of these converging threads upon the abdo- men of the moth as it emerges from the cocoon, has the effect of forcing the fluids to enter the nervTires of the wings, and give them the proper expansion, having noticed that the moths from chrysalides taken out of these cocoons were crippled in their wings. "atoms organized." 11 size and gigantic expanse ? The \nsdom of the Creator is concentrated in these minims of creation, in order the better to develope His power ; since in these creatm-es, whose ex- cessive minnteness renders it difficidt, and even impossible, to observe some of them with the unassisted eye, how can we conceive it possible to arrange all the machinery which exists in the bodies of these " atoms organized," as perfect and as complex as in those of the largest ? The little beetle {Atomaria atomos), and the minute parasitic fly {Mymar monas), although not one-hundredth part of an inch in length, possess precisely the same number of organs, and even of joints of those organs, as their larger bretln-en of the tribes to which they respectively belong. To neglect this portion of the creation is to say, that these living machines, in which the rules of the most perfect mechanical knowledge have been imphcitly followed, and of which the various parts are arranged with the utmost art, but which are nevertheless so fine and dehcate as to escape our view, are less worthy of regard than the larger machines made precisely upon the same model. Absm'd reasoning ! Who does not regard the skill of the artificer capable of forming a minute pocket-watch, with its delicate machineiy, as more worthy of notice than that of the workman who can but construct a town-clock. The benefits and injuries resulting to mankind from these creatures (insignificant though they may be regarded) are, moreover, amply suificient to prove that they are, on the contrary, well deserving of his attention, either \\ith a view of extending the former or diminishing the latter. Of their obnoxious powers all are more or less directly or indirectly cognizant, their minute size insuring them success in their assaults, and scarcely permitting the possibility of extirpa- tion. On the other hand, the benefits we experience from insects are scarcely less extensive, semng as an ample counterbalance against their attacks upon our properties or 12 INTRODUCTION. persons. If we would therefore endeavour successfully to combat the latter, it can only be done by the acquisition of a knowledge of their habits, in every state of their existence ; and, in this point of view, the study of Entomology becomes of the highest importance. Let us take, for instance, the case of the turnip-flea beetle (or turnip fly, as it is often called — Haltica nemorum), and we find that all the numerous investigations of the Don- caster Agricultural Associa- tion have proved next to useless, because the natui-al history of the insect itself was not ascertained. In hke manner it must be equally Tn,„;„ fl», «»„.i» evident, that the diffiision of 1 urnip-nea Ueetle. ^ correct knowledge, and more especially inquiries into the chemical properties of many insects, hitherto considered useless, might be the means of adding considerably to the hst of benefits conferred by insects on man. Amongst the Crustaceous Annulosa many species of crabs, lobsters, prawTis, and shrimps are employed to a very great extent as articles of food ; and even amongst the mnged or true insects various species are found similarly serviceable. In the deserts of Africa and Asia, where the locusts ac- quire a large size, those insects are employed, when dried and preserved, as food. I have tasted locusts thus prepared, and found them not unpalatable ; but they are said to pos- sess very little nutritious quahty, and to produce disease when too much is eaten. The larvae or grubs of many large beetles are also devom-ed by the negroes of India and Ame- rica : and even the luxurious Romans were exceedingly fond of a large fleshy grub which they called Cossus, and which is supposed to have been either the larva of the Goat-moth INSECTS USED AS FOOD, ETC. 13 {Cossus ligniperda), or that of the Stag-beetle {Lucanus cervus). In like manner the white ants {Termites) are de- voured by the savages of Africa and America ; whilst the great quantity of honey annually consumed in every quarter of the world is sufficient to prove, that in this point of view insects are highly beneficial. It has also been recently discovered, that the manna which, it will be remembered, served the Israehtes for food during their passage through the Wilderness, is but the con- creted juice of an Arabian tree {Tamarix mannifera), which is caused to flow by the puncture of a small species of Coc- cus, which the celebrated Prussian entomologist. Dr. Klug, has recently described and figiu-ed under the name of Coccus manniparus, in his splendid work upon the insects of Arabia, and to whom I am personally indebted for specimens of this interesting insect. In medicine insects are also of great service. Of these the Cantharis vesicatoria or bUster beetle Blister Beetle. is the most important. Numerous other species were for- merly introduced into the Pharmacopoeia, but they have gra- dually been disused. In a commercial point of \iew, silk, chermes, and cochineal are some of the most important pro- ducts. There are many other insects which construct silken cocoons, and emit various colom*ed dves, and which it might 14 INTRODUCTION. be very serviceable to endeavour to introduce, as well as the true silkworm and the Coccus cacti. Gumlac also, wax and ink-galls are insect productions of too great importance to be passed over without notice. But there are other classes Theluk-gall entire, and cut open, with the insect by which it is produced {Ci/nipstinctoria.) of benefits resulting from the relations of insects with other organized beings. These, although less directly affecting man, ought not to be overlooked in a general survey of the economy of natm'e. Suppose the race of insects to be en- tirely annihilated, and then observe the thousands of ills which would inevitably result from the putrefying masses of animal and vegetable productions, and which are now, as it were, reduced to their native elements solely by the interfer- ence of the insect tribes. The entire tribes of Silpha, Ne- crophagi, Dermestes, Nitidul(S, immediately fall upon the dead carcases of animals, devom'ing the flesh, and accelerat- ing the dissipation of the putrid mass; and these, assisted by myriads of flies, which deposit their eggs in the decomposing body in such immense numbers, succeed, in a very few days, in reducing the carcass to a mere skeleton. In hke manner, the ScarabicediB (whose extraordinary habits of rolhng their eggs in globules of dung caused them to be regarded as sacred by the Egj'ptians), the GeotrupidcB, Histeridce, and many other insects, are equally serviceable in biu-rowing into the earth underneath the fallen excrements of animals, and thus disseminating them, rendering them serviceable to GENERAL ECONOMY OF INSECTS IN NATURE. 15 Scarabaeus ^eryptiorum. the agriculturist; whilst the tribes of insects which feed upon decaying vegetable mat- ter are even still more nume- rous. As serving for food to some of the higher animals, as fish, bu'ds, some of the smaller mammalia, &c., insects are emi- nently serviceable in the scale of the creation. Amongst birds, the shrikes, and the genera Sylvia, Motacilla, Anthus, Cer- thia, Muscicapa, and Hirundo, as well as the cuckoos and pies ; and amongst quadi'upeds, the genera Stenops and OtoUcnus, which feed upon grass- hoppers, the bats, shrew, hedgehog, mole, and especially the genus Myrmecophaga, derive their sole nutriment from insects. Many species of insects are equally sen'iceable in destroying other noxious insects. Of these the tribes of predaceous beetles, sandwasps, ants, dragon-flies, spiders, &c., are to be noticed, but more especially the larvae of the lady- birds, Syrphidce, and golden-eyed flies, which destroy mpiads of plant hce. All these, however, yield to the Ichneumonidce, which annually destroy more caterpillars than the whole tribes of insectivorous birds, having almost universal dominion over the other insect tribes. In the last place, we have to notice the great services rendered by insects in efi'ecting the im- pregnation of plants, in many of which the position of the sexual organs is such, that the intervention of insects, especially bees, butterflies, &c., is required, which, whilst seeking food for then* ovm. nourishment, unconsciously per- form this most important ofiice ; whilst some of the CynipidcB eff"ect the more rapid ripening of the fig, by the process termed caprification by the inhabitants of the Levant. 16 INTRODUCTION. It is, however, necessary for us now to reverse the pic- ture, and to observe, that if insects are capable of being serviceable to mankind, other species are not less injurious to him and his property. We will first notice such species as possess a chrect influence against mankind. Of these the various species of hce, the flea, jigger, and the bed-bug, are pre-eminently obnoxious. Besides these, we are condemned to suff'er from the occasional attacks of multitudes of other species, which at all hours of the day cease not their tor- Gnat {Culex pipiens) female, natural size and magnified, with the head of the male. menting powers. Moreover, the hotter the clime, and the period when the body requires the greatest portion of rest, the more numerous are the hordes of our insect enemies. The Tabani, Stomoxes, and Asili, are all highly irritating ; but all these yield to the gnat and the musquito, which are sometimes so annoying and so numerous, that their victims have sunk under their attacks. They both belong to the same natural group, Culicidcsj and as they breed in stag- nant water and damp situations, it does not seem impro- bable that the last-named insects were the species of flies which were emplo3'^ed as one of the ten plagues of Egypt to ])unish the rebellious Egyptians. In the article Bat, in the British Cyclopaedia, there is the following passage, which especially bears upon the subject : — "The banks of the Nile, PLAGUE OF FLIES. 1/ in Egypt, where they (the bats) dwell in the palaces and sepulchres of forgotten kings, and the temples of forgotten gods, are particulal-ly replenished with them, because the swelling and subsiding of the Nile cause a vast production of insect life." Mr. Kirby, indeed, adopts another opinion, suggested to him by an eminent and learned prelate, that the Egyjjtian plague of flies, which is usually supposed to have been either a mixtm-e of different species, or a fly then called the dog-fly {Kvvojxvia), but which is not now kno\\Ti, was a cockroach, the Hebrew name of the latter, which is the same by which the raven is also distinguished, furnishing no shght argimient in favour of it, the same word also sig- nifying the evening. Hence, as the cockroach of Egypt is black, and appears only in the evening, Mr. Kirby considers the reason sufficient for the name given to it. I am afraid of being charged with presumption in venturing to differ from these learned divines on a point of bibhcal natural history, but I cannot avoid adopting the opinion, that the plague of flies was caused by the musquito. Mr. Kirby e\idently appears to have previously adopted the view of the subject given by Bishop Patrick, who says of these flies, that they were "flesh-flies or dog-flies, very bold, troublesome, and venomous. Some think the Hebrew word means a mixtm'e of different insects, all manner of flies;" and Bruce regards it as being probably identical with the insect which he describes under the name of the zimb. We read, on the denunciation of this plague, that Moses was directed to say to Pharaoh, " If thou wilt not let my people go, behold I will send swarms of flies upon thee and upon thy servants, and upon thy people, and into thy houses; and the houses of the Egj'ptians shall be full of swarms of flies, and also the ground whereon they are ; and I will sever in that day the land of Goshen, in which my people dAvell, that no swarms of flies shall be there," &c. Now in this passage wc are c3 18 ' INTRODUCTION. first struck with the expression " swarms of flies ; " and we are sure that every one who has seen " a swarm of gnats at even-tide" will perceive the aptness of the expression, sup- posing the Egyptian fly to be a species of gnat, or, in other words, the musquito. We next read of their making their way into the houses, which shall be full of flies. This is also precisely the habit of the Culicidce. The next passage, that they should also swarm upon the ground, is certainly not in favour of my interpretation, and would apparently apply to some other species ; but it is in the last passage quoted that we perceive the fullest corroboration of my view of the subject. Bryant says, "The land of Goshen was a tongue-like piece of land, where the Nile first di^dded at a place called Cercasora; Said, or Upper Egypt, lying above, and Mesre, or Lower Egypt, was in a line downward;" and Bruce states, that " the land of Goshen was a land of pasture, not tilled or sown, because it was not overflowed by the Nile. But the land overflowed by the Nile was the black earth of the valley of Eg}^t, and it was here that God con- fined the flies, for He says it shall be a sign of this separa- tion of the people which He then made, that not one fly should be seen in the sand or pasture-ground of the land of Goshen ; and this kind of soil has ever since been the refuge of all cattle emigrating from the black earth to the lower part of Atbara." These observations appear to me almost conclusive upon the question : the sandy pastm-e soil of the land of Goshen would have been the spot where the cockroach would have resorted to naturally, and it is the spot where the musquito would not have been found. Far be it from us to deny the miraculous power of the Almighty in producing this sm*prising flight of flies, but we know, in our owTi days, that in certain seasons certain species of insects are multiphed to such an extent as to become a posi- tive evil. We know not, of course, for what end such niul- MUSQUITO. 19 tiplication is permitted by the Creator : but in the one case, as well as in the other, we must certainly acknowledge the working of an all-wise Providence, which sees and under- stands what man cannot comprehend. I am aware that Dr. Hale and Bryant have given calcu- lations, whereby it would appear that this succession of plagues took place between the month of January and the beginning of April, and consequently the plague of flies, &c. must have been miraculous, occm'ring at a season when the Nile was at its lowest, and when flies, &c. were not naturally abundant; but there seems nothing fully to warrant the adoption of a fixed period of time between the early plagues. I have said that the musquito is a species of gnat {Cu- licidce), nearly allied to our common EngUsh species, C. pi- piens. In making this statement I have followed the best authorities. Mr. Kirby says, that the musquito from Bata- via, whose bite is exceedingly venomous, occasioning a most intolerable itching, which lasts several days, is distinct from the common gnat, and approaches C annulata, but the wings are black, and not spotted. Robineau Desvoidy and M. Percheron have described and figured the insect under the name of Culex musquito; and Pohl and Kollar have de- scribed the Brazilian musquito, as it is termed by the Portu- guese, under the name of Culex molestus. There is also another little insect, which in the autumn is very annoying to persons w^ho walk about the fields, and which is so minute that it escapes observation. It is called the harvest-bug, but is in reahty one of the Acarida, of a red colour, its mode of attack being to insinuate itself into the flesh of the legs, where it causes an intolerable itching, and raises the most irritating sores. An analogous species inhabits the West Indies, where surgical operations are required to dislodge it, causing, if neglected, abscesses, gan- grene, and even death. The name of Scholechiasis has been 20 INTRODUCTION. applied to a disease in which the larvae of various species of insects are found in the human body, but these appeal- to be entirely accidental cases, wherein these larvae have been injected. A species of (Estrus, in like manner, has been found to be parasitic within the bodies of persons residing in the tropics, but this (although it has received the name of (Estrus hominis) I should be rather induced to regard also as an accidental locality selected by the insect, instead of its real habitat. There is another tribe of insect enemies whose attacks are not less annoying, although not resulting, like the former, from a desire to feed upon om* bodies. Here are to be ranked the bees, wasps, and other insects pro\ided with poisonous stings, which, however, they seldom employ except in their own defence, or to resent injuries oflfered to them. Here also may be added the spiders, whose powerful jaws are equally provided with a poisonous fluid, as well as the scorpion, whose long and jointed tail is de- fended at the tip with a powerful sting. Other insects are to be ranked amongst our minor miseries, namely, those which by the emission of a caustic or disgusting fluid, operate strongly upon our olfactory nerves. But the tribes of insects which prey upon our cattle are equally numerous, including Gasterophilus eqai. 1 - 2 Gasterophilus bxmorrboidalis. fleas of diff'erent species, ticks, gadflies, forest flies, and especially the remarkable family of (Estrideous flies, the ATTACKS OF INSECTS UPON PROPERTY. 21 larvae of some of which are ordinarily termed hots. In Uke manner our poultry and our bees are subject to the attacks of various insects, of which the Death'' s-head moth and the Galleria are examples. Death's-head Moth. It is not, however, to ourselves and li^^ng animals that the ravages of insects are confined, almost every species of property being in some measure or other liable to be injured by them. Oiu* clothes, and other woollen productions, are devoured by the larvae of various species of clothes-moths, which not only feed thereon, but also form for themselves coverings of the same materials ; and the richest furs are subject to the attacks of a similar insect ; whilst our mu- seums are equally ravaged by the Dermestes and Anthreni. Our furniture is often completely destroyed by the timber- boring beetles and death-w^atches {Anobium) ; and some sj^ecies of white ants, in warm climates, are so destructive in this respect, that if a chair or table be sufi'ered to remain for a time in the same situation, the interior substance wiU be completely consumed, nothing remaining but the outside shell, which the insect has the instinct to leave entire. The last-named insects may indeed be regarded as amongst the most destructive of our insect enemies, since they scarcely leave any article untouched. Ants also are, in warm ch- 22 INTRODUCTION. mates, almost as destructive; and, even in our own coun- try, one of the smallest spe- cies of ants {Myrmica unifa- sciata) has increased to such an extent in certain parts of London, and some other towns, devouring all kinds of articles, that the inhabitants Atta ccphalotm, the visiting ant of the haVC bcCU COmpcUed tO Quit West ladies. '■ '■ their abodes. Our provisions are also not less liable to the attacks of insects ; bread and flour are devoured by the blattae and meal-worms, and we have seen ship-biscuit swarming to such a degree with the grubs of a species of Anobium as to be worse than useless. The Dermestes feed upon our dried meats. Cheese is attacked by mites, and the cheese-fly, the grubs of which are termed cheese- hoppers, from their singular motions. Our granaries are ravaged by the corn weevil and by the larvae of a species of tinea ; but if we turn our attention to the species of insects which attack such Uving vegetable productions as are most gratifying to the taste of mankind, we find the catalogue wofully augmented. Cheese-fly {Piophila casei). I need scarcely mention the locust as being the most redoubtable of our insect enemies in this respect, although. WHEAT INSECTS, ETC. 23 fortunately for our country, tlieir ravages are here unknown, except by description. Our wheat whilst in blossom suffers from the attacks of the Hessian fly Cecidomyia tritici and C destructor, the larvae of which devour the pollen. Cecidomyia tritici and destructor. whilst its roots are devoured by the larvae of the Zabrus gibbus, which sometimes, as in the^ear 1812, near Halle, in Germany, is produced in such numbers, that v.hole corn fields are entirely destroyed. The larvae of some of the Elaterida, kno^Mi by the ordinary name of mre-worms, also attack its roots, as well as the roots of various other garden plants and culinary vegetables. The grubs of the cock- chafer in like manner often do much injury, by devouring the roots of grass, as do also those of the Tijmlcs. Of the former, an instance is recorded by Kirby and Spence, in which all the fields of a farmer near Norwich were entirely destroyed, and as many as eighty bushels of the insects were collected by him and his men. Various other esculent roots are also de- voured by the larvae of other insects ; amongst which the damage occasioned by the onion-fly {Anthomyia ceparum), the grub of which destroys the plant when still very young, is perhaps the most obnoxious. In like manner the stems and the pith of trees and plants are equally subject to the ravages of insects, amongst which may especially be noticed 24 INTRODUCTION. the various species of Scolytidce, of whose appearance and proceedings some idea may be obtained from the accompa- i^*' 2 I, 2, Tomicus typographus— 3, 4, 5, 6, Hylurgus piniperda (natural size and magnified) . nying figures. The gigantic larvae of the longicorn beetles, goat-moths, Siricida, &c., are not less destructive, by Track of Typographer Beetle under bark. boring through the solid wood of various trees ; whilst an ant {Formica saccharivora), which takes up its abode in the stem of the sugar-cane, has proved at certain periods in the highest degree injurious. But it is upon the leaves and INSECTS ATTACKING PLANTS. 25 young buds, and stems of plants, that insects are the most detrimental in their attacks. Of these the tui*nip-fly {Hal- tica nemorum), and some other species, hold the foremost rank. Several species of Apion devour the seed of growing clover. Entire and extensive families of beetles {Crioceridee, Chrysomelidce, &c.) are similarly employed in devouring the leaves of various plants, as well as the numerous species of saw-flies ; but it is among the Lepidoptera Apion. t^^t this species of injury occurs in the highest degree, whole forests being sometimes entirely defoliated by various species. In like manner the flowers and fruits of various plants are subject to similar devastation by insects. It would, however, require an entire enumera- tion of vegetables and their attendant species of insects, in order to lay before the reader a complete account of the ravages of insects upon oiu* vegetable productions ; since it is to be observed that, for the most part, the latter are destined by an all-wise Creator for the support of the for- mer. Their ravages, therefore, which man regards as inju- ries towards himself, are but the natui-al result of the ordi- nary workings of the economy of nature. A few observations upon this branch of the subject, and with reference to the emplo}Tnent of remedies against the attacks of these noxious insects, will not be considered out of place. ' One of the most common, and at the same time most weighty charges brought against the entomologist is, that whilst he bestows endless labour and trouble in collecting and preser^dng the various species of insects, his attention is never, or but very rai'cly, directed to inquiries into the most eff'ectual remedies against those insect scourges which nature has inflicted upon our vegetable productions. He is told over and over again, that to make the science which he cultivates more beneficial to society, and thereby more generally known, a share, at least, D 26 INTRODUCTION. of his attention must be occupied in prosecuting experiments for the purpose of discovering how this or that insect enemy may be combated in the most successful manner. And, in- deed, it must be admitted, that this is a charge too well founded, although, perhaps, a few observations may con- vince those who are the most ready to bring it forward upon every opportunity, that it may be greatly palhated. In the first place, therefore, it may be lu-ged, that these destructive insects, appearing as they do in occasional seasons in vast profusion, are produced in such myriads for some wise pur- pose, which we may not be permitted to understand. They, like the locusts, of which so splendid a poetical description is recorded in the second chapter of the prophet Joel, form a portion of the army of the Almighty wherewith He scourges the nations ; and, although the scientific researches of man- kind might discover means of destrojing, in some degree, these hosts, it may perhaps not unreasonably be supposed either that he would not be allowed to frustrate the designs of Pro^idence, or that, if this evil were removed, others per- haps more weighty might arise in their stead. In the second place, the minuteness of the size of these creatures presents an almost insurmountable barrier against those delicate in- quiries and examinations of them, during every state of their existence, by which alone we can arrive at a knowledge of the real nature and cause of the mischief, and be thereby, and thereby alone, enabled to judge of a smtable remedy. In the third place, the want of a sufficient opportunity for such researches is not the least objection which may be brought against the charge. It must be admitted, that no effectual check can be given to the ravages of any species of noxious in- sect, until its entire habits and economy have been ascertained. Thus far in the inquiiy is the strict province of the entomolo- gist, whose attention ought to be directed from day to day, and from year to year, not to isolated spots of ground, but to whole REMEDIES AGAINST INSECT ENEMIES. 2/ acres, more especially with reference to the peculiarities of seasons, and to atmospheric changes ; but here we have only gone half-way. It now becomes the province of the agricul- turist to discover a remedy, since it seems equally clear that this ulterior branch of the inquiry can only be prosecuted effectually by persons perfectly conversant with the chemi- cal nature of soils, the action of various ingredients which may be employed as remedies, not only upon insects them- selves, but also upon the plants which may be attacked. Such persons too are alone able to judge of the practicability of the apphcation of the proposed remedies, since it would be useless for an indoor entomologist to endeavom* by expe- riment to discover remedies which, when discovered, cannot be adopted from the great expense of the article itself, or the impossibihty of applying it, or the habihty of the de- struction, not only of the insect, but also of the plant itself: and even instances of the latter description have been re- corded. Hence we must evidently look for the discovery of the most efficient remedies to persons who, residing in the country, are the best enabled to obtain a knowledge of the economy of these destructive insects, founded upon the most general and practical modes of examiuation, and who unite the entomological knowledge requisite to trace most effectually their habits, with a perfect and scientific know- ledge of the true principles of agricidtiire. Thus it seems undoubted, that this want of sufficient opportunity for inves- tigation has hitherto proved one of the greatest barriers to our proposing satisfactory remedies agaiust these ravages ; and kno\^ing, as we too well know, that the study and inves- tigation of this branch of zoology have hitherto been almost uncultivated amongst us, it is not, perhaps, surprising that so httle has been done. The observer of insects has, in- deed, proposed remedies which the agriculturist cannot 28 INTRODUCTION. adopt ; and the agriculturist, on the other hand, ignorant of the nature of insects, has pursued the very plan which has been the most congenial to the habits of the insects which he ^vished to destroy ; as in the case of the French gardener, mentioned by Reaumur, who, thinking to destroy the cater- pillars of the cabbage-moth, buried them just at the time when they were themselves on the point of going into the earth to change to chrysalides. Such being the claims which the objects of the entomolo- gist's study possess upon his attention, I next proceed to state the most efficient modes of research, w hereby, also, the most satisfactory and pleasing return may be obtained for the toils of investigation, premising, that all animals destitute of in- ternal vertebrae, having articulated bodies and articulated legs in the perfect state, are here regarded as insects. Entomologists, like the objects of their research, may be classified. First, there is the amateur, whose sole object is the procuring, either by capture or by purchase, of a collec- tion of handsome insects, either to be placed in drawers, without any other arrangement than that of beauty of colour or size, or in glazed picture-frames, to be hung up in his room. This, it is true, is the lowest class of entomologists ; but the labours of such amateurs are not without pleasure to themselves, and are sometimes serviceable to the science of Entomology. The delightful sensations with which the pent- up entomologist inhales the breeze upon Shooter's Hill or Wimbledon Common, when on the w^ay to those well-known entomological spots, Darenth and Coombe Woods, are real enjoyments. The best practical collector whom I have ever heard of is Daniel Bydder, a Spitalfields labourer, by whom some of the most interesting of our English insects were first discovered. And, in like manner, Joseph Standish, a Brixton cobbler, from a pure love of entomology, taught himself to draw and paint insects; and having followed up this COLLECTION OF INSECTS. 29 pursuit, during his leisure of many years, at length acquired the art of giving to his figures of moths a beautiful do\Miy appearance, so hke nature, that we have known a voliune of his dramngs sold for many pounds. Can it be denied that if, amongst the lower classes, the collecting of objects of nature, and such-like piu'suits, were more general, the vice of drunkenness and the reign of gin-palaces would be over ? It is not of course my intention, in this work, to lay dowTi an accoimt of the instruments required, or the modes of col- lecting insects, for the information of the mere collector. These will be found in Kirby and Spence's Introduction, in the " Insect Miscellanies," or in Mr. Ingpen's httle manual devoted to this subject. Sufiice it to say, in this place, that when captured and killed, either by immersion in scalding water (as is usually done mth beetles), or by being placed in a close small box, -with bruised laurel leaves (as is very ser- viceable with flies, moths, &c.) the insect is stuck through one of the wing cases (if a beetle), or between the wings (if a fly or moth), with a pin proportioned to its size ; the entire collection being preserved in chip-boxes, or in a cabinet of Instruments for collecting Insects. A, The large gauze flap-net ; b, The sweeping or water net ; c. The gauze forceps ; d. The collecting bottfe for holding small beetles, &c. ; e. The breeding cage. shallow glazed drawers, having the bottom hned with cork and covered with paper. d3 30 INTRODUCTION. Various kinds of nets are employed in collecting insects, such as the flap-net, for catching insects on the \\'ing, made of fine gauze, resembling a bat-fowling net, and the sweeping net, for catching insects on gi-ass and low herbage, made of strong canvas, and resembling a landing net. When secured, the insects are either immediately pinned, or carried home loose in quills or glass bottles. After they are killed and pinned, their limbs are arranged in a natural position by means of pins and bits of card, by which they are retained in their places until they are dry enough to be placed in the cabinet. Caterpillars are kept in boxes with gauze sides, and fed with leaves of the peculiar plants upon which they are found, until they assume the chrysaHs state ; and in this manner moths and butterflies are procured with their plumage much more beautiful than when captured at large. Insects which may have become stiff before they have been dis- played, are readily relaxed by placing them upon. damp sand for a few hours. It is necessary that the store-boxes, or cabinets, containing insects, shoidd be kept in a diy situa- tion, otherwise the specimens soon become mouldy. It is not advisable to place them against an outside wall of an apartment ; moreover, it is necessary that camphor should be kept in Httle cells in the drawers, to prevent the attacks of mites or other insects, especially the species of the Coleo- pterous genus Anthrenus. The insects of this genus are deserving of attention, both from the ravages which their larvae commit upon preserved animal substances, objects of natural history, &c., and from the curious formation of the larvae themselves. Perhaps there is nothing more curious amongst insects than that, during the preparatory states of an animal, its habits should be totally distinct from those of its adult state. The per- fect Anthreni are generally found on flowers, preferring, as we have often observed, those of umbelhferous plants. They RAVAGES OF ANTHRENI. 31 employ their wings, seeking, after impregnation, to penetrate every spot where dried and preserved animal remains are to be found, in order to deposit their eggs in such situations. They counterfeit death, also, like the Byrrhij and, from their small size and banded colom'ing, look like small seeds. In the larvae state they are exceedingly destructive, especially in museums, whence they have obtained the name of museum beetles, devouring the internal parts of bird skins, preserved insects, &c., and attacking feathers and hairs, reducing all to powder. They must not, however, be confounded with the Tinea, or small fleshy grubs found in similar situations, which form for themselves cases of hair, woollen, &c. The larvae of the Anthreni, on the contrary, are uncovered, except by their o\\n coating of hairs, which are disposed in bundles, the posterior part of the body being fui'nished with tw o large patches, which are longer than the rest, and each of which is thickened in a singular manner at the tip. These crests, as they may be termed, are so arranged that the insect has the power of spreading them out, in which position it affords a very beautiful object when magnified. The perfect insects are of a rounded and depressed form, the surface of the body being adorned with undulated bands of coloured scales, which are easily rubbed off. The antennae are terminated by a three-jointed club, and are capable of being retracted and concealed in grooves on the under side of the thorax, which is produced behind, on its upper side, into three lobes. There are five or six British species, of w^hich the Anthrenus (BjTrh.) Musaorum of Linnaeus is the type, and which seldom exceeds one-eighth of an inch in length. These hints will suffice for the practical collector and the professed amateur ; for the more systematic entomologist, who is not content with merely collecting insects, but who is intent in classing his collections, aiTanging each in its proper 32 INTRODUCTION. place and under its proper name, and describing such as are nondescript, another plan of study is requisite. Of the natui'e of the pursuits of this class of entomologists, Messrs. Kirby and Spence, (having previously spoken of them as possessing an agreeable and unfailing provision of that "grand panacea for the tedium vitac," — employment,) make the following observations : — " With what view is the study of the mathematics so generally recommended ? Not cer- tainly for any practical purpose — not to make the bulk of those who attend to them astronomers or engineers, but simply to exercise and strengthen their intellect — to give the mind a habit of attention and investigation. Now, for all these pm'poses, if I do not go so far as to assert that the mere ascertaining of the names of insects is equal to the study of mathematics, I have no hesitation in affirming that it is nearly as eflfectual, and, with respect to giving a habit of minute attention, superior." Examples are then given of the necessity for minute discrimination in the examination of insects, for the purpose of discovering the proper name of each and the descriptions to be given of it, if it should happen to be undescribed : but there is still another advantage to be gained from this kind of investigation. It may be asserted that no one who has studied the classification of insects, commenc- ing mth the class, and going regularly through the orders, sections, famihes, genera, down to individual species, and neatly arranged his insects in his cases, can leave the subject without having gained certain principles of regularity and order, which will communicate themselves to his every-day employment, inducing a methodical correctness and preci- sion in the details of life, which are so superior to the care- less proceedings of the thoughtless and irregular. By the student, therefore, who would attempt the classifi- cation of his collection, it is requisite that a progressive series of inquiries should be made. It is not advisable that GENERALIZED VIEWS OF ENTOMOLOGY REQUISITE. 33 be should commence by the mvestigation of isolated species : bis collection must be in the first instance generalized, since it is only by studying groups of insects in the mass that we can ever acquire any general \dews of the science. If this be not done, we shall be constantly falling into the error of separating intimately alhed groups, because their external appearance is different, and of uniting insects which, from the difference of their organization, are mdely apart, because their appearance is similar. Let us take any every-day ex- ample of the want of this generalized ^iew of insects. There is an extensive group of two-vvinged flies which are called drones : they are the very personifications of luxm-iant idle- ness — they do nothing but sip the nectar from the brightest flowers, and enjoy the sunshine basking upon the leaves of plants ; and there is an extensive group of bees, having the same general appearance, but being in habits the very reverse of the drones — toihng all day long, either in the construc- tion of the nest, or in provisioning it -mih pollen paste. Now, by ignorant persons, the same name is given to both groups of insects, and not the slightest idea is entertained of the totally opposite natm'e of their habits. A, Drone-fly {Erist.tlis). b. Spring wild-bee {^Anthophora retusd) . I am the more anxious to impress upon the reader the ne- cessity for obtaining a generalized view of insects, and indeed of the entire productions of nature, because it is well known tliat manv of our fellow-labourers fritter awav their talents 34 INTRODUCTION. and time in the sole elucidation of the characters of obscure species of insects, vtdthout a thought of the higher views which lay open before them. " English naturalists," says Mr. Bicheno, " appear to me, from various causes, to have pursued the nomenclature and examination of species in such a way as very much to exclude from their attention the higher ends of science, in which alone the bulk of mankind is interested. Ever since the subject has been pursued in the spirit of true philosophy, it has almost solely been con- fined to the analytic form, which, however important, is apt to degenerate into unprofitable detail, as the sjTithetic mode leads oftentimes to the other extreme of loose and imprac- ticable generahzation." "The necessity of knowing psir- ticulars has made our researches into species very minute, and has given to our operations in the eyes of the multitude rather a puerile cast. The method by which the name of an unknovra species, and all that has been written about it, can be discovered, necessarily involves such minute discrimi- nation, that it cannot escape this superficial objection. It is, however, an inconvenience not incident to our subject alone, but to all the sciences, more or less, which require a minute examination of particulars." And he concludes by observing, " I am anxious not to be misunderstood ; I do not want to disengage natm-alists from attention to the analysis of species, or to absolve them from the labour of minute investigation, which, after all, is our chief business ; but I do wish to see them foUomng natm'e through all her varieties, with a view to generalize as well as to particu- larize ; to relieve the memory from the overwhelming mul- titude of names which the discovery of new species has im- posed ; and to compress the result into a size adapted to the human capacity. This may safely be pronounced to be among the highest efforts of a created intelhgence." Hence will be seen the necessity for studying collections INVESTIGATION OF INSECTS. 35 of animals, and particularly of insects, in the mass; for though the knowledge of species, as Mr. Kii'by has well ob- served, is indispensable for the registry of facts and other practical purposes, yet the knowledge of groups leads to a higher wisdom ; and indeed it is through these that we best descend to the study of species. The first thing, therefore, requisite is, to ascertain to what order of insects any indi- vidual specimen may belong. For this pm'pose an inspection of the mouth (for the purpose of ascertaining whether it is fiu-nished with jaws or with a sucker), and of the structure of the wdngs, will generally suffice. The next step is the separation of your collection into the primaiy sections and famihes of which the orders are composed; and here, of course, the characters will vary in the diiferent orders ; for instance, in the order of beetles (Coleoptera), the primaiy sections are founded upon the variations in the number of joints in the tarsi (or last articulated part of the leg) ; w^hereas in the two-winged flies {Diptera) this character is constant, and the number of joints in the antennae consti- tute the leading characters of the primary divisions. For the families, no better rule could be laid do\\Ti than to study the characters of the Linnsean genera, which in fact corres- pond generally with the modern famiUes of insects ; but, as will be more fully detailed in a subsequent page, the con- tents of these groups have so immensely increased since the days of Linnaeus, that it has become necessary to sub- divide them into minor divisions, to which the names of genera and sub-genera have been given ; and here it will be necessaiy to have recourse to such authors as Fabricius and Latreille, Stephens or Curtis, for obtaining an idea of the extent to w^hich these subdivisions have been carried, as well as for obtaining a knowledge of the various subdivisions themselves. The practised eye, indeed, can readily reduce an extensive family of insects into its sectional groups, without 36 INTRODUCTION. any other assistance than that derived from long experience, because the most nearly allied species possess such a gene- ral resemblance to each other, that it is almost impossible to overlook their relationship : for instance, the restricted genus Carabus comprises a very extensive series of ground-beetles, varpng but little in size (com- pared ^nth the variations in size which occur in the family), being moderately large, and orna- mented more or less with me- tallic tints ; so also among but- terflies, the genus Colias com- prises species being generally of a brimstone colom*. We now arrive at the investigation of the specific name of the insect un- der examination ; and here hes a great difficulty, owing in gene- ral to the number of species; great relief, however, is afforded by the introduction of subdivisions in the longer genera, by which we arrive almost immediately at the name of the spe- cies itself. In general the descriptions of insects are written in Latin, or at least, if an author chooses to give a specific description in his native tongue, it seems by common consent and usage to be required that he should commence his de- scriptions by a short Latin character, which, from the almost universal emplojnnent of that language in works of natural his- tory, is intelligible to naturalists throughout the world. More- over, the indication of the natural length and expansion of an insect, the addition of the country which it inhabits, and the references to the works of other authors by whom the species may have been described, and especially where it has been figured, all tend to render this branch of the science Carabus clathratns. OUT-DOOR ENTOMOLOGIST. 3/ less intricate than it at first appears. If, however, after all research into the works of those authors who have especially devoted their attention to the family or genus of insects, to which the one under examination belongs, it should be evi- dent that it is a nondescript, its description, embodying the points of distinction which it presents \nth reference to the already described species, and whether residting from struc- tural variation, or from difierences of colour, or of striation or puncturation (as in the beetles), maybe attempted, taking as models the specific descriptions contained in such ad- mirable monographs as those of Mr. Kirby upon the English bees or the genus Apion, or that of Latreille upon the ants. But the investigation of species, although valuable for the sake of precision in the identity of the object which is the subject of observation, is by no means essential for enabhng us to study the structure or economy of an insect ; and this brings to our notice several other classes of entomologists, who more especially merit the title of philosophical observers of nature. Of these the out-door naturalist first claims our attention. Instead of running from one end of the country to the other, climbing mountains and descending valleys, stopping only so long as may be necessary to transfix the luckless objects of his chase, and deeming himself happy only when liis collecting box is filled \^ith specimens, the real observer of natm-e finds materials for study even at his o^Mi door. The former, it is true, meets with many rarities, and even perhaps nondescript species ; but notwithstanding all his toil, has he observed a single fact relative to the his- tory and economy of a single insect ? Swammerdam and Reaumur toiled not thus, and yet then* labours are read even now by all the world, whereas the labom-s of the collector are but at best selfish, and the descriptions of his new spe- cies read only by a few amateur collectors hke himself. Seek then a spot favourable for the habitations of insects — E 38 INTRODUCTION. a sunny nook in a wood, a hot sandbank, or the margin of a stream, and watch the proceedings of the numberless insects which frequent these spots. Examine, for instance, the clear water, and watch the movements of the various aquatic insects with which it abounds ; and especially observe the silvery silky globe which the diving water-spider bears about with it, and in which, in an enlarged form, it passes the mnter. Observe the mode Diving water-spider, in its diving bell, fixed tQ plants at the bottom of the water. in which the butterfly, resting upon a flower, extracts the honey from its cup : trace the flight of the sandwasp, and notice the pecuharities of its manoeuvres in the construction of its bui'row : examine with careful eye the movements of the sawfly in the act of forming a channel in the sprig for the reception of its eggs ; or listen to the chirping of the field-cricket, and trace it to the bm*row, at the mouth of which it sits ready to dart upon its prej\ Notice these things, and then say whether these and a thousand other observations of a similar nature are not in - finitely more interesting than the mere pursuit and capture of specimens, or the dry technical detail necessary for their specific determination. " Those who have studied nature only in books," observes St. Pierre, " can see only their books in nature : they look ADVANTAGES OF STUDYING FROM THE LIFE. 39 upon the natural world only to find therein the names and the characters of then* systems. If they are botanists, they are satisfied to have discovered a plant of which some author has spoken, and ha\dng assigned it to the class and the order which he has pointed out, they gather it, and spreading it between two bits of grey paper, they sit down content with their knowledge and their researches. They do not form a herbal to study natiu-e, but they study natm'e to form a herbal. It is in the same way that they make collections of animals, that they may learn their genera and species, and treasure up their names. But can he be a lover of nature who thus studies her wonderfid works ? How great a differ- ence is there between a dead vegetable, dry, faded, dis- colom*ed, whose stems and leaves and flowers are crumbling to powder, and a hving vegetable, full of sap, which buds, flowers, gives forth perfume, fructifies, and sows itself again — maintains an universal harmony \\ith the elements, with in- sects, with birds, with quadrupeds, and, combining 'oith a thousand other vegetables, crowns our hills and adorns our banks. The animal loses by death even more of its charac- teristics than the vegetable, for the animal has received a more ^^gorous portion of life. Its principal qualities vanish, its eyes are shut, its pupils are dim, its limbs are stiff, it is wthout warmth, without motion, Tvithout feeling, Avithout voice, without instinct. What a difference between the ani- mal which enjoys the light, distingmshes objects, moves to- wards them, calls the female, couples, makes its nest or lair, brings up its young, defends them from their enemies, con- gregates with its kind, and gives music to our woods, and animation to our meadows." But the out-door observation of these and such-like sub- jects by the real lover of nature — and no one merits this name who does not bestow attention of this kind upon the objects of his research, leads to far higher considerations and 40 INTRODUCTION. views. Peculiarities of economy (and herein almost every spe- cies of animal differs from its neighbour,) necessarily involve corresponding peculiarities of organization, at times, indeed, minute, and to be sought after mth great care and labour, and often with the assistance of the microscope. The philosophi- cally minded student \vill therefore combine with the observa- tion of habits, investigation of structure, and in this latter par- ticular hes the merit of such laborious natm-alists as Lyon- net, Swammerdam, or Strauss-Durckheim, who lay open to our view the minute intricacies of the internal anatomy of various species of insects. The following observations upon the connexion between these two branches of our subject, from the " Introduction to the Menageries," will be read with pleasure, from the soundness of the views which they inculcate : — " It is amazing how much quickness the habit of observation will impart to the whole intellect, and give it an aptitude for understanding and enjojing the thing observed. There is nothing, for instance, so common as to find men wanting in a perception of picturesque beauty, of that feel- ing which enables some to take great delight in a landscape, not only for its extent, or the grandeur of its parts, but for the harmonious arrangement which is necessary to the effect of a picture, or for some accidental circumstances of light and shadow, or of colom", which render the prospect more than usually attractive. Now this is strictly an acquired faculty, and one which is produced by the practice of looking at nature, or at the monuments of art, with the previous adaptation of the vision to picturesque objects ; and a per- son who enjoys the faculty (we say enjoy, for it is a source of real pleasure) is said to possess a painter's eye. It is pre- cisely in the same way that a naturahst, by constantly ob- ser^dng the pecuHarities of animal hfe, acquires the readiest perception of the differences in the structure and habits of the great variety of living beings, and he perceives in each of them quahties which a less practised observer would entirely STRUCTURE DEPENDENT ON HABITS. 41 overlook. Through these habits of observation, the science of zoology, which comprehends all that relates to the de- scription or classification of animals, has been gradually established. By diligent observations, the peculiar structure of vast numbers of individual animals has been ascertained; their habits have been accm'ately described, and many ancient errors, which arose from hasty examination, have been ex- ploded. Thus, in the more recent scientific works on zoology, the accidental circumstances of size or colour, or locaUty, or any identity in unimportant habits, have ceased to be guides in the classification of animals, but the essential ^peculiarities of ilieir formation, which chiefly determine their habits, have alone been regarded. We mention this, to point out that the actual observations of successive naturahsts, leading to the accumu- lation of a great body of facts, have principally contributed to the advance of zoology as a science in modern times; for the science being wholly founded upon observation, and not upon previous calculations, or any series of experiments, the greater om* collection of facts the nearer have we approached to systematic perfection." These views so fully coincide \y\t\\ my own. opinions of the necessity for continual observation of facts, that I have not hesitated to introduce them into this place, as they are equally valuable with refeifence to every department of zoology. The observation of facts has been too much neglected amongst us ; there is, however, one passage contained in the above extract, which appears to call for fm'ther notice. We are there told that "the essential peculiarities of formation chiefly de- termine the habits" of animals, and a little fm-ther we meet vAt\\ the remark, that the systems of Cuvier, Blumenbach, and others, are founded upon a consideration both of the teeth and of the organ of touch, and therefore, "being formed with especial reference to the two great distinctions which de- £ 3 42 INTRODUCTION. termine the most important habits of the animal, are called natural systems." Now this passage, and numerous others which I might quote from the works of other modern \\Titers, both popular and scientific, to the hke effect, appear to me to result either from very incorrect ideas of the system of nature, or from a carelessness of expression which leads us to imply the exist- ence of such incorrect ideas. Let me not be misunderstood. These passages seem to imply that, in the opinion of the writers, a certain formation being bestowed upon an animal, certain peculiarities of habit dependent thereupon are ac- quired. Observe the result : — If we adopt this mode of looking at the operations of nature, do we not immediately fall into one of the worst errors of some of the worst of the French philosophers ? Do we not at once virtually deny the existence of design in the creation ? It was upon this very point that our great philosopher, John Ray, contended with such eloquence in his "Wisdom of God in the Works of the Creation." Against the doctrine, that the bodies of men and aU other animals were the effects of the wisdom and power of an intelligent and Almighty agent, and the several parts and members of them designed to the uses to which now they serve, the atheist, he observes, has one subterfuge in which he most confides, viz., that all these uses of parts are no more than what is necessary to the very existence of the things to which they belong, and that things made uses, and not uses things; and in this spirit Lucretius says, Nil ideo natum est in corpore ut uti Possumus, sed quod natum est, id procreat usum : And again — Omnia denique membra Antefuere, ut opinor, eorum quam fuit usus. So that, in the opinion of the atheist, all this admired and STRUCTURE DEPENDENT ON HABITS. 43 applauded usefulness of their several fabrics is but a neces- sary condition and consequence of their existence and pro- pagation. If it could be proved that the doctrine contained in such passages as those I have quoted, ought not to be identified wdth the atheistical doctrines above alluded to, and refuted so ably by Ray, I would not have noticed the subject in this manner ; but when it cannot be denied that the only inter- pretation to be put upon the former coincides so exactly with the latter, I think it my duty to guard my readers, and es- pecially my younger readers, from unheedingly falling into a train of thought in which the fore-knowledge and har- monious contrivances of an all-wise Creator, with reference to preconceived and intended uses, are virtually denied ; at~ tributes which it is expressly \vithin the duty of the zoo- logist to hold up to con- templation and admiration^ and which the objects of his study so continually present to his view. I have pur- posely abstained from en- tering into the arguments adduced by Ray in refuta- tion of these atheistical opinions, the opposite view being fortunately too clear to need much argument in its support. He would be but a sorry architect who, having completed the building of a splendid palace, had not, previously to its erection, planned the uses of its various apartments, and adapted the size and situation of each to its intended uses. We have thus seen that it is by the continual accumulation of facts, and by noticing the adaptation of structure to habits. A, fore leg of the mole cricket, formed for y(>/^t// /fi CAjaaP//tY )////i j^ i^^fAf f^ efy/A '////'> ■^/f/(^ ee z //iy cti •yr/Vt'/f /f.t />>/■/>//}, y'ux'?/i^z/^^f/'^fy^.j ^t'f<-J RELATIONS OF THE CRUSTACEA. 81 own country the recent observations of Johnstone, Hailstone, and Fleming, anil the beautiful work of Mr. J. V. Thompson, have shown that the subject is not neglected amongst us. The Crustacea, regarded under the different relations ex- hibited by their organization, ought imquestionably to oc- cupy an elevated range in the annulose sub-kingdom. They ought not, indeed, to be far removed from the Arachnida and insects, which, like themselves, have a symmetrical body incased in a hard corneous covering, performing the offices of an external skeleton, and with articulated legs, eyes always apparent, sexes distinct, &c. They are, however, evidently much farther removed from the Annelida, in which the body is destitute of true articulated limbs, the eyes wanting, and the generation often hermaphrodite. These last, indeed, in many respects inferior both to the Crustacea and Insecta, seem to be more nearly allied to the intestinal worms and Epizoaria. With respect again to the fishes, with which they are vulgarly associated, their relations are very trifling indeed*; but with the mollusca, especially such as the Ce- phalopoda, there is much greater affinity, so that thev might naturally be placed after them in the series of animals ; but as we find other mollusca, such as the Gasteropoda and Ace- phala, still less perfectly organized, we should either be com- pelled to introduce the Crustacea in the midst of them, or to place the mollusca either after the entu'e group of annu- losed animals, as the ancients did, or before the Crustacea, as the more recent zoologists have done ; and this latter step is confirmed by the observations of Latreille, w4io has proved * A celebrated zoologist recently requested a friend who was going' a long sea-voyage, to bring him home all the fishes he could procure. "Yes," was the reply, " I will catch you all kinds, from a whale to a shrimp ; " neither of which, as eveiy person acquainted with the slight- est outlines of zoology well knows, are fishes. This anecdote shows that a little knowledge would not have been a dangerous thing, in this instance at least. 82 CRUSTACEA. the existence of the great affinity between certain of the least perfectly organized fishes, and the most perfectly organ- ized mollusca, as the Cephalopoda. The following are the characters by which the animals of this class are distinguished from the other annulosa. They are destitute of internal vertebrae, having white blood ; the body divided into various segments (differing in number), incased in a crustaceous envelope, and provided with articu- lated legs ; respiring by means of brauchise or branchial plates, ordinarily annexed to the base of the legs or lower jaws ; having a distinct heart furnished with visible vessels, with legs, of which the number is generally five or seven pairs, and always destitute of A^angs ; head generally con- founded with the thorax, fm'nished with two pairs of an- tennae, and a pair of mandibles (often palpigerous) ; two pairs of lower jaws, and three pairs of foot-jaws (the two posterior pairs of which are transformed into two additional pairs of legs, when there are seven pairs of the latter or- gans) ; mouth also furnished mth an upper and lower lip, or rather a tongue, the external pair of foot-jaws j^erforming the office of a lower lip ; eyes two, facetted, often borne upon footstalks ; sexes distinct ; sexual organs placed either at the base of the legs or the extremity of the body. And here may be noticed the great difficulty existing in the determination of the nomenclatm-e of the different or- gans in the various groups of annulose animals, some of which recede so entirely from those which, by common con- sent, are considered as the types or normal divisions of the class ; — and, indeed, the remark is applicable in every other branch of the creation. I mention this subject, because Dr. Johnston, the celebrated naturalist of Berwick-upon- Tweed, has recently published some observations bearing upon this view of the question, in the Magazine of Natural History, which deserve attention. Speaking of one of the NOMENCLATURE OF ORGANS. 83 species of the shark parasites {Pandanis alatus), he says : — " The student who is anxious to see how ingeniously the few and simple organs of this creature can be analysed and re- solved into parts corresponding with the complex organs of the crab and lobster, must consult the interesting memoir of Milne Edwards (in the Annales des Sciences Naturelles, tom. xxviii.) I must acknowledge that the analogies seem not a little imaginary, and the nomenclature derived from them is at least faulty, in so far that it gives, or is apt to give, erroneous ideas relative to function. The feet-jaws are not subservient to manducation in any way ; the animal is suctorial, and requii'cs no jaws, and these organs are used solely to obtain fixedness of place ; while the thoracic feet again are not organs to walk or creep on, but are only calcu- lated for s\\imming, which, we can conceive, it may often have occasion to do." Although we may admit to its full extent the soundness of Dr. Johnston's remarks in examining an animal per se, we certainly do feel, when investigating the same animal with reference to the structm-e of the remainder of its class, that the great difiiculty with which the subject is surrounded ought to make us hesitate before we condemn a series of names which the strictest analogy has proved to be correct. Let us, however, look at the matter with reference to some of the better known examples of the class. Examine a lobster and a crab, and the mouth is found to be exter- nally composed of several pau's of flattened organs, having a transverse motion, and e^ddently acting as jaws, whilst the large pair of fore legs is terminated by great and powerful claws. Now, examine the spiny lobster, and the claws are no longer to be seen; in their stead a pair of limbs are found, ha\'ing indeed the same number of joints as claw-legs, but formed like the following legs, and evidently being em- j)loyed in locomotion. But will it be said that the least stretch s given to our fancy when we assert that the foreleo; of 84 CRUSTACEA. tlie Palinurus is the claw of the lobster in a modified state of developement, or that the former analogically represents the latter ? Should we incur the chance of ridicule if we describe the claw of the lobster as a leg, although it be employed only in prehension, and not in locomotion ? Let us, how- ever, now examine one of the little leaping shrimps, so com- mon on the sea-coast, and of which one species abounds in fresh water {Gammarus pulex), and we find the mouth defi- cient in a certain number of pairs of organs, but that the legs have obtained an increase of the same number of pairs ; whilst the examination of such genera as Sergestes, Sicyonia, &c., clearly demonstrate the transition of structure and func- tion from mouth organs to legs. Will it be said that we are adopting a faulty nomenclature, because we employ a term for these thus altered organs, which indicates that they are liable to this singular kind of transition? I am aware that, by the unthinking, (and by those who would lead the unthinking by the employment of arguments resting upon general, and, as we may say, vulgar observation, rather than upon accurate but difficult analysis,) we should be ridiculed in asserting that the sucker of the butterfly, and the under- jaws of a beetle, are the same organs in a different state of developement, and in applying to both the same term ; but I contend that the arguments which I have above brought forward are applicable to one case as well as the other ; that there is no fanciful theory to be built upon this strict appli- cation of the rules of analysis and consequent analogies; and that when, by the application of the former, and the adoption of the latter, we arrive with certainty (and here, as I said in the outset, lies the great difficulty) at the conclu- sion that a certain organ in one animal is the representative of an organ in another animal, we are at liberty, in a strictly ])hilosophic view of the subject, to apply to both the same name, although in common parlance it is necessary, perhaps, SENSES. 85 to use different terms, indicating the precise functions of each organ. The class ^vhich we are now considering may be regarded as taking the place in the water which insects occupy on land. They are very varied in then* forms, as well as size, some of them being in fact the giants of the sub-kingdom to which they belong, whilst others are of a microscopic minute- ness. Some species are of a globular or oval shape, others square, whilst a few are linear and elongated ; some again have the body quite flat, others are compressed, and in a few the covering of the body, instead of being hard and crusta- ceous, exists in a softened and membranaceous state. These animals possess the ordinary senses which the infe- rior animals are gifted \^-ith, although, from the great modifi- cation in their structure, as compared with that of the verte- brated higher animals, it is difficult, and, indeed, often impossible for us to assign them to theu* legitimate organs. That they taste is evident from the fact that they are not indifferent to the kind of food which they meet \^ith, and which, indeed, they seek ^nth much assiduity. The very complex organization of their mouths, the developement of which far sm-passes that of insects, must doubtless be re- garded as incUcating the seat of this sense. The organs of sight are ver}' distinct, in the greater number existing as facetted eyes, borne upon footstalks, often of a very great length, as in Podophfhalmus j often, however, they are ses- sile, that is, not elevated upon the siu'face of the head or shell. The structure of the eyes of these animals has lately been studied xevj minutely by M. Muller {Ann. Sc. Nat., July, 1829). The sense of touch, from the hard envelope in which these animals are incased, must in all probabihty be greatly diminished, especially in the more crustaceous spe- cies. The circumstance that they are ])rovided with t\AO I 86 CRUSTACEA. pairs of antennae, as well as several pairs of palpi attached to the jaws and foot jaws, seems to favour the opinion that this sense is transmitted by means of these organs. The sense of hearing has not been distinctly proved to be possessed by these animals ; it has, however, been supposed that the seat of this sense was placed in an excavation observed at the base of the external pair of antennae in certain of the larger species, as the lobster, &c., in which cavity it has been stated that a small sac filled mth fluid exists, in the midst of which a nervous thread was fixed : it is certain, however, that the aperture of this cavity is closed by a membrane, and that in some cases there exists (as in Maia) a small crustaceous organ or moveable operculum, the use qf which appears to be, to distend the membrane which shuts the orifice. Of the distinct existence of the sense of smell we are also equally ignorant, although from analogy we are led to beheve that it is possessed by these animals. Its seat is also unknown, although Rosenthals and Robineau considered that it existed in a pair of small orifices at the base of the internal pair of antennae. The minute Crustacea, whose growi;h is very rapid, change their coats at very short intervals of time. Thus, Jurine observ^ed that the younger Daphniae moulted eight times in seventeen days, but amongst the large species, such as the crabs and lobsters, this only occurs once a year. In general, the Crustacea ha\dng previously obtained such an increased supply of food, as to make their shells too confined for the increased size of theu internal organs, they cast their entire skeleton, as we may term it. Previous to doing this, they appear sick, languid, and restless, seeking some secluded place, in which they may securely remain until theii* new covering shall have attained a sufficient consistence. In casting their shells it is difficult, at first sight, to conceive MOULTING. 8/ bow it is possible tbat the inclosed claw, for instance, can be so completely drawn out of the old covering, through the narrow part by which it is attached to the body, so as to leave the shell of the claw entire, and attached to the exuvia of the body, in which state they are constantly found. The new shell, however, is at fii-st quite soft and membranaceous, so that we may thereby account for this circumstance, with- out adopting the opinion of the fisherman, that the lobster pines so much before moidting, that the flesh of its large claw is reduced to the size of a goose-quill, which enables it to di-aw its parts through the joints and narrow passage next the body. Still it is e\'ident, that the forcing of the inclosed claw, even if ever so soft, through so nai-row a passage, must be exceedingly painful. It is to Reaumur that we are in- debted for our knowledge of the precise cu'cumstances con- nected with this cm-ious phenomenon, that distinguished author having imprisoned several crayfish about to moult, in pots pierced with holes, placed in running water. It is said, that it is easy to perceive when the period of moulting is approaching, by pressing the backs of the animals, when the shells )-ield readily to the pressm-e of the finger, not off'ering that resistance which is common to them. The animals then beat their legs with violence against each other, the body is in a complete agitation, the membranes between the seg- ments being greatly distended, so that the shell is raised considerably from the abdomen, the membrane bursting which connects them. By degrees, the entire shell and ex- ternal covering is shed, and in the com-se of two or three days, or even twenty-four hours, the new skin has acquired a proper consistence. Another circumstance of a still more remarkable nature occurs on these renew als, namely, the re- production of the claws and legs when accidentally broken oflf. In some species, indeed, the limbs are so slightly 88 CRUSTACEA. attached, that the least touch causes them to shed them. lu hke manner, it is said that lobsters fear thunder, and are aj)t to cast their claws on a great clap, and that they will do the same on the firing of cannon ; so that when men-of-war meet a lobster boat, a jocular threat is used, that if the master does not sell good lobsters, they will salute him. In the course of a day or two, the naked skin exposed by the wound is found to be covered with a reddish pellicle, which soon assumes a convex siu-face, grows longer, becomes conical, increases in size, and splitting, exposes to view a soft body, composed of the same number of parts as had been lost. This soon gains the consistence of the remainder of the body, but never acquu-es the size of the limb lost, although, at every subsequent moulting of the skin, the size increases more rapidly than that of the rest of the limbs. This curious phenomenon involves, in a singular manner, the principles upon which the moulting of the annulosa takes place. We are taught that the wings of a butter- fly exist in the caterpillar state, and that the legs of the larva of a grasshopper envelope the legs of the perfect insect : if, therefore, we admit the theory of Swammerdam, subsequently noticed, as regards the true insects, we shall be compelled to establish another theory for the Crus- tacea, similar to that of Dr. Herold, also subsequently men- tioned. Reaumm* has, indeed, attempted to explain the causes of this reproduction of limbs ; inquiring, if, at the base of each leg, there may not be a provision of new legs, as in children there is a tooth under the milk tooth ! I am sm-prised that so acute a reasoner as Reaumur should not have perceived the incorrectness of such a supposition. It is perfectly natural that the milk-teeth are one day des- tined to fall, and it is natural that their places should be occupied by fresh teeth, which are accordingly provided. METAMORPHOSES. 89 But it is perfectly unnatural — merely accidental — that the lobster should lose its claws ; and it is equally unnatural to suppose, that nature should have provided a series of organs which, in the majority of instances, woidd be totally useless, depending only upon accident for their casual develope- ment. The female Crustacea, after impregnation, deposit a vast number of eggs, which, in many instances, are retained beneath the abdominal portion of the body, whilst in some, as in the opossum shrimps {Mysis), the sea wood-lice {Iso- poda), they are retained in a kind of a sub-thoracic pouch, and in others they are placed in a membranaceous bag, or pail- of bags, dependent from the base of the abdomen, as in the Cyclops, Branckipus, &c. It has been generally stated in all works upon this class, that with a very few exceptions, the young, when hatched from the eggs, closely resemble their parents in form; these exceptions occurring in Cyclops, the young of which were regarded by Muller as belonging to two distinct genera {Amymone and Nauplius), Argulus, and Branckipus. Indeed, Dr. Leach, one of the chief investiga- tors of this tribe of animals, has assigned it as one of their principal characters, that they undergo no metamorphosis. Mr. J. V. Thompson of Cork, has, however, lately published a series of memoirs, in which he has announced " that the greater number of the Crustacea do actually undergo trans- formations. The circumstance of the Crustacea being sup- posed to pass through no intermediate form, has been brought forward heretofore as one of the arguments for theii" separation from insects ; but although the fallacy of that opinion may diminish the number of characteristics which distinguish these two tribes of animals as distinct classes, there yet remains those depending on the anatomical structure of their respiratory and circidating systems, which are quite sufficient to render their separation permanent. It 1 3 90 CRUSTACEA. may also be observed, that the changes presented to our notice in the Crustacea are quite pecuhar, and of a totally different description from those of insects." Mr. Thompson then proceeds to notice the different extraordinary animals kuo^^'n to naturalists under the name of Zoea, Avhich, from their pecuhar structure, had greatly perplexed systematic crustaceologists, and states, " It will no longer be a matter of surprise that all the leading naturalists of the present day should have been at a loss how to dispose of Zoea in their arrangements of the Crustacea, when it is known that this singular type is not a perfect animal, but merely the larva or imperfect state of the crab ! and not, as has been imagined, an animal sui generis.'^ Subsequently, this author states, amongst other circumstances, that he, " succeeding in hatching the ova of the common crab, during the month of June, which presented exactly the appearances of Zoea Taurus, with the addition of lateral spines to the corslet; the Crustacea then indisputably undergo a meta- morphosis, a fact which will form an epoch in the history of this generally neglected tribe, and tend to create an interest which may operate favourably in direct- ing more of the attention of naturalists towards them."* And as the Zoeae are aquatic animals, furnished \\ith smmming organs, Mr, Thompson concludes, that tne CU'tUmStance OI me y OUng Zoea, stated to be hatched from the /• . 1 /-^ , 1 • .1 ejfirs of the common crab. 01 the Crustacea bemg thus na- (The natural size indicated in the scroll) tatory, enables us satisfactorily to account for the annual * Zoological Illustrations, p. 9. MR. Thompson's observations doubtful. 91 migration of the land crabs of the West Indies to deposit their eggs in the water. Mr. Thompson has subsequently pubhshed several memoirs in the Entomological Magazine, and elsewhere, in which he has stated that the eggs of other Decapods produce various kinds of Zoese. I have here given Mr. Thompson's observations at some length, because the facts, if fully established, are highly interesting. It is proper, however, to state, that Dr. Rathke has, in a series of microscopic observations, far more elaborate than any hitherto published by Mr. Thompson, clearly shown the gradual de- velopement of the cray-fish within the egg, and which, upon bursting into life, possesses all the form of its parent, and has also announced a memoir* in opposition to Mr. Thomp- son ; whilst the Rev. Lansdown Guilding has expressly stated that the land crabs do not undergo any metamorphosis {Maff. Nat. Hist., May, 1835) ; and in a memoir which I have pubhshed in the Philosophical Transactions for 1835, I have fully confirmed Guilchng's statement : thus, two examples in the great divisions of Br achy ur a and Macroura are shown to militate against Mr. Thompson's assertion, that the Crustacea universally undergo metamorphosis ; and, as the organization of those two animals is so completely analogous to that of the common crab (the young of which Mr. Thompson affirms to be a Zoea) and the rest of the Decapoda, I cannot but think that Mr. Thompson must have fallen into some funda- mental error in his observations ; at least, it is certain that the researches of Mr. Thompson are made without any of that anatytical precision which is so obviously requisite in such a matter. It would, indeed, be a remarkable thing, * " As to tlie Decapods, so far as I have examined their developement, I must deny such an assertion [as that made by INIr. Thompson] ; and of them I can say nothing- less than that, at the end of their existence in tlie eg;s, they have exactly tlie same aspect, and are as fully developed, as the full-arrown individuals." — Rathke. 1837. Annals Naf. Hist. 92 CRUSTACEA. that some of the higher Crustacea undergo no meta- morphoses, whilst others closely related to them are meta- morphotic. Various modes of distribution of this class have been pro- posed by different crustaceologists, which it would occupy too much space to detail : I shall, therefore, proceed to give a short sketch of that which appears to be the most natural hitherto published, namely, that by Latreille in the second edition of the Regne Animal, premising, that the distribution of M. Edwards, founded primarily upon the manducatory or suctorial nature of the mouth, appears to be less natural than that given below. CLASS CRUSTACEA. SECTION I, — MALACOSTRACA. Shell of a sohd consistence ; legs ten or fom-teen ; mouth with a labrum, two mandibles, four maxillae, six or ten (ac- cording to the number of legs) foot jaws. SUB-SECTION I. — PODOPHTHALMA. Eyes on footstalks. ORDER I. DECAPODA. Legs ten ; foot jaws ten; branchiae in a cavity at the side of the thorax. ORDER II. — STOMAPODA. Branchiae not inclosed beneath the shell at the sides of the thorax ; legs more than ten. SUB-SECTION II. — EDRIOPHTHALMA. Eyes not elevated on footstalks. ORDER III. AMPHIPODA. Body compressed ; mandibles palpigerous. ORDER DECAPODA. 93 ORDER IV. L^EMODIPODA. Abdomen rudimental, with only the rudiments of one or two pairs of appendages. ORDER V. ISOPODA. Body depressed ; abdominal appendages flat and plate- like J mandibles not palpigerous. SECTION II. ENTOMOSTRACA. Shell not solid; legs variable in number; mouth very variable. ORDER VI. BRAXCHIOPODA. Mouth ^^'ith a labrum, two mandibles, a tongue, one or two paii-s of maxillae ; legs natatory ; branchiae situated an- teriorly. ORDER VII. P.ECILOPODA. Mouth suctorial, or destitute of mandibles and maxillae, but defended by the ambulatory legs which perform this office. ORDER VIII. TRILOBITA. Body 13-23-jointed, divided above into three lobes by two longitudinal impressions. ORDER I. DECAPODA. This order comprises all the larger species of the class, and is well characterized in having ten legs ; the head inti- mately united with the thorax, and covered by a large shell, carapax, or shield ; a mouth, consisting of numerous pairs of organs, of which the outer pairs, in some of the species, are elongated ; but the most characteristic trait consists in the existence of gills or branchiae, more or less numerous, fixed in a pecuHar cavity beneath the sides of the shell. This order is divided into two sub-orders, namely, 1. Brachyura, having the abdomen shorter than the tho- 94 CRUSTACEA. rax, beneath which it is folded in repose, and not furnished with a terminal fan-like tail. The common crab is an example of this sub-order. 2. Macroura, having the abdomen longer than the thorax, beneath which it is not closely folded when at rest, and fur- nished with a fan-hke tail. The lobster, prawn, and shrimp, are examples of this sub-order. M. Milne Edwards, one of the most celebrated of modern crustaceologists, in a valuable work pubhshed at Paris, in 1834, has proposed the establishment of another or third division, under the name of Anomoures, forming a passage between the two other groups, and composed of various spe- cies which appear to belong to neither, and which, if intro- duced amongst them, would violate the spirit of all natural arrangement. In the various animals which compose the sub-order Brachyura, the shell or carapax which covers their bodies also conceals the greatest portion of the abdomen, and is in general of a square, oval, or rovmded form, its transverse diameter exceeding,or at least equalling, its length, its upper surface exhibiting various areas divided by impressions, which correspond for the most part with the insertion of the muscles within the shell, and which form so many regions corre- sponding with the internal organs immediately beneath the different areas. The front of this shell bears a pair of eyes placed on footstalks (marked c in the figure), and two pairs of antennae (a, b), and beneath these is perceived a pair of large, flat, and articulated pieces {d), which, when raised, are found to conceal a very complex apparatus, composing the mouth, and consisting of an upper lip and tongue, a pau* of horny mandibles bearing a jointed palpus, a pair of internal* and external maxillae, and three pairs of foot jaws * By some accident M. Edwards has described the internal maxillae as the anterior foot jaws, p. 255. SUB-ORDER BRACHYURA. 95 gradually increasing in size, furnished with palpi, the largest of which is the external pair first mentioned ahove. Beneath Cnrcinus Masnas (Common small edible Crab). the antennae is also placed a pair of apertm-es, which have • been regarded as organs of hearing. The members which immediately succeed the external foot-jaws constitute the legs, and are also five pair in number (e, /, g, h, i) ; they vary considerably in size ; those of the first pair are always prehensile, and terminated by a didactyle and well-formed claw ; in general, the four posterior pairs of legs are simply ambulatory or natatorj^, — they are never didactyle. The ab- domen (k) is but slightly developed, its length never exceed- ing three-fourths of that of the entire body, and its thickness not equal to more than one-sixth or pne-tenth of the body, being in fact lamellose, and always closely applied to the sternal excavation. It is essentially composed of seven seg- ments, but it often occurs that some of these are so inti- mately soldered together, that this part of the body appears 96 CRUSTACEA. to be only five, four, or even three-jointed. In general, it is mucli larger in the females than in the males, being oval in the former and somewhat triangular in the latter. The sub-order Brachyura comprises a very great number of species, respecting the classification of Avhich, crustaceo- logists are not yet agreed. Dr. Leach, followed by M. Des- marets, arranged the groups according to the number of pieces of which the abdomen is composed, both in males and females, — a very simple plan, and one of very easy applica- tion, but at the same time one which produces the most ar- tificial results, some species belonging to the same natural genus being removed thereby to different families. M. Latreille, on the contrary, founding his earlier classifications upon the general form of the body and the disposition of the feet, established seven famihes, namely, the Nageurs (paddle- legged), Arques (arched front), Quadrilateres (four- sided), Orhiculaires (orbicular {ormed), Triangulaires (triangle formed), Cryptopodes (hidden legged), Notopodes (dorsal footed). Subsequently, however, he took into consideration the form of the mouth and some other characters in addition to the preceding, the result whereof was the union of the Nageurs and Arques into one family, and the modification of the others. The latter classification appeared the most natural of any hitherto proposed to M. Edwards, who has, how^ever, been induced, from an investigation of the structure of the different groups, further to modify various portions, and to subdivide the Brachyura into only four great families, w^hich he terms Oxyrhynches, Cyclometopes, Catametopes, and Oxystomes. The OxyrJiyncha (or Maiadce, LithodiadcB, and Macropo- diadcB Leach), comprise the various species of crabs kno^ATi by the name of sea-spiders, or thorn-backed crabs. The legs are long, the shell more or less narrowed in front THE CRAB. 97 into a beak, the epistoma (or part of the head between the antennae and mouth) very large and nearly square. This family comprises three tribes, Macropodietis, Maiens, and Parthenopiens. The Cyclometopa (or Canceridce, Portunidce, and Pilumnidee Leach), have the shell very large, regularly curved in front and narrowed behind ; the legs are of moderate length ; the epistoma is very short, and much wider than long. The ab- domen of the male occupies all the space between the hind legs. This family comprises two tribes, the Canceriens and the Portuniens ; the former comprising three sub-tribes, the Cryptopodes, Arqiies, and Quadrilateres. The type is the common echble crab {Cancer Pagurus). The Catometopa {Oc7/2}odiad(S heach), have the shell qua- drilateral or ovoid, ^Aith the front transverse and knotted ; the epistoma very short ; the abdomen of the male not occu- pying the space between the hind legs. The common pea- crab (Pinnotheres Pisum) is an example of this order. The Oxy stoma {Corystidice and LeucosiadcB Leach) have the shell orbicular and arched in front, which is not produced into a point. The epistoma is obsolete. This order com- prises the stone-crabs. The animals belonging to the decapod Brachyura ai-e known under the common Enghsh name of Crabs, and to which, in the Linnsean system, the name of Cancer was ap- plied. The term, however, is not exactly s^Tionymous with the latter name, as the lobster, craj-fish, shrimp, prawn, &c., formed portions of the Linnsean genus. Since the time of LinuEcus, however, the study of these animals has greatly increased, so that the animals knoA^Ti now by the ordinary name of crabs compose the sub-order Brachyura, whilst the Macroura comprise the other species above mentioned ; Ijut still, as if to show the total disagreement of the or(hnary K 98 CRUSTACEA. terms in natural history with their scientific hmits, the king crab of the tropical seas belongs to a totally different order of Crustacea than either of those above mentioned, whilst the hermit crab belongs to the Macroura. Crabs are for the most part marine animals, frequenting the rocky shores of the ocean. We regret the very slight attention which has been paid to the habits of these marine animals. They are found in all latitudes, but are more abundant in the warm and temperate cUmates than in more northern regions. Some genera, as Ocypoda, Gecarcinus, Uca, Grapsus, &c., frequent more southern regions, being found in nearly equal latitudes, in the different parts of the old and new world. Others, as the true crabs, Por- iunus, &c., are more generally distributed, extending from the equator to the polar circles. The local habitations of these animals are, however, very varied. Some species, although having the form of marine crabs, do not quit the fresh water, as in the TelphuscE. Again, amongst the marine species, the majority do not quit the shores, whilst others are found at great distances in the high seas, where they can rest only on the floating banks of sea-weeds, so abundant in the tropics. And even in those species which frequent the coasts, the same situations are not congenial to them all : some, as Dorippe and the Inachi, reside at great depths of the sea, from two to four hundred feet, whilst others keep continually at the surface of the waters, passing a great part of their existence upon the shores continually washed by the waves. Some species, again, frequent only the rocky parts of the coast, abounding in madrepores and difficult of access, whilst others prefer sandy shoals, in which they bury themselves. Amongst the land crabs some species, as the Ocypod