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tinder new genera, as we shall have occasion to notice still farther in a subsequent study. In the new and untried soil of America, the bones of unknown kinds and species lie buried in profusion; and my late friend Professor Barton, of Philadelphia, one of our first transatlantic physiologists, informed me by letter a short time before his death, that they are perpetually turning up skeletons of this description, whose living representatives are nowhere to be met with.

In few words, every region has been enriched with wonders of animal life that have long been extinct for ever. Where is now that enormous mammoth, whose bulk outrivalled the elephant's 1* where that gigantic tapir, of a structure nearly as mountainous,* whose huge skeleton has been found in a fossil state in France and Germany; while its only living type, a pigmy of what has departed, exists in the wilds of America? where is now the breathing form of the fossil sloth of America, the magaloninx of Cuvier, whose size meted that of the ox ?* where the mighty moniter,* outstripping the lengthened bulk of the crocodile? itself, too, a lord of the ocean, and yet, whose only relics have been traced in the quarries of Maestricht; to which, as to another leviathan, we may well apply the forcible description of the Book of Job, "at whose appearing the mighty were afraid, and who made the deep to boil as a caldron: who esteemed iron as straw, and brass as rotten wood; who had not his like upon the earth, and was a king amid the children of pride."f

Over this recondite and bewildering subject skeptics havelaughed and critics have puzzled themselves; it is natural history alone that can find us a clew to the labyrinth, that enables us to repose faith in the records of antiquity, and that establishes the important position, that the extravagance of a description is no argument against the truth of a description, and that it is somewhat too much to deny that a thing has existed formerly, for the mere reason that it does not exist now.

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While every department of nature displays an unbounded scope to the contemplative mind,—a something on which it may perpetually dwell with new and growing delight, and new and growing improvement; we behold in the great division of the animal kingdom a combination of allurements that draw us, and fix us, and fascinate us with a sort of paramount and magical captivity, unknown to either of the other branches of natural history; and which seem to render them chiefly or alone desirable and interesting, m proportion as they relate to animal life. There is, indeed, in the mineral domain, an awe, and a grandeur, and a majesty, irresistibly impressive and sublime; and that cannot fail to lift up the heart to an acknowledgment of the mighty Power which piled the massy cliffs upon each other, and rent the mountains asunder, and flung their scattered fragments over the valleys. There is in the realm of vegetables an immeasurable profusion of bounty and of beauty, of everything that can delight the external eye, and gratify the desire; simple, splendid, variegated, exquisite. But the moment we open the gates of the animal kingdom a new world pours upon us, and a new train of affections take possession of the bosom; it is here, for the first time, that we behold the nice lineaments of feeling, motion, spontaneity; we associate and sympathize with every thing around us, we insensibly acknowledge an approximation (often indeed very remote, but an approximation nevertheless) to our own nature, and run over with avidity the vast volume that lies before us, of tastes, and customs, and manners, and propensities, and passions, and consummate instincts.

But where shall we commence the perusal of this volume? the different pages of which, though each intrinsically interesting, lie scattered, like the sibyl leaves of antiquity, over every part of the globe, and require to be collected and arranged in order, to give us a just idea of their relative excellence, and to enable us to contemplate them as a whole.

The difficulty has been felt in all ages; and hence multiplied classifications, or schemes for assorting, and grouping into similar divisions, such individuals as indicate a similar structure, or similar habits, or similar powers, hare been devised in different periods of the world, and especially in modern times, in which the study of zoology has been pursued with a searching spirit, unknown to the sages of antiquity.—And well has it deserved to be so pursued. "This subject," observes M. Biberg, "is of so much importance, and of such an extent, that if the ablest men were to attempt to treat it thoroughly, an age would pass away before they could explain completely the admirable economy, habits, and structure even of the most imperceptible insect. There is not a single species that does not, of itself, deserve an historian."*

Before we gird ourselves then to a critical indagation into any particular part of the immense theatre which this study presents to us, it may be convenient to contemplate it upon that general survey which it is the object of such schemes or classifications to lay down; to travel over it and mark its more prominent characters by a map, anterior to our entering upon the country itself. And such are the humble pretensions of the present lecture; which will merely attempt to place before you a brief sketch of zoology, in

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regard to its bare outlines; for such a sketch is the whole that our time will allow; yet if it be found faithful, it will assuredly be found beneficial; for if the outlines be correctly laid down, the picture may be filled up at our leisure.

That most sublime and magnificent of all poems, ancient or modern, the Book of Job, establishes, in the most satisfactory manner, that the study of natural history, and especially the history of the animal kingdom, was cultivated at a very early period of the world,—in all probability as early, at least, as the Mosaic epoch,—with a considerable degree of minute attention in regard to various kinds and species; and the detailed references to the habits and manners of other animals that lie scattered through almost every part of the Hebrew Scriptures, and especially through the book of Psalms, and those of the Prophecies, and the distinct historical notice which is given of the scientific acquaintance of Solomon with this attractive study,* establish, not only that it was attended to at a very early period, but that it was a very favourite and fashionable pursuit for many ages throughout Egypt, Syria, and Arabia. But the first physiologist who, we can say, with any degree of certainty, pointed out the expediency of a methodical arrangement of animals was Aristotle. His works upon this subject have reached us; yet while they prove that he took the same extensive and scientific view of it which he did of all other subjects, to which he directed the wonderful powers of his comprehensive mind, they prove also, that the study of natural history in Greece had by no means, in his day, kept pace with a variety of other studies; and that he did not conceive, aided as he was by all the mighty patronage of Alexander the Great, and the concurrent exertions of every other physiologist, that he was in possession of a sufficiency of facts to attempt the same kind of systematic arrangement here, which he is so celebrated for having effected almost every where else. He modestly contented himself, therefore, with pointing out the important use of such an arrangement as soon as it could be accomplished, and with suggesting a few hints as to the principles upon which it should be constructed. He observes, that the distinctive characters of animals might be taken from the nature of their food, from their actions, their manners, or their different structures. That their inhabiting land or water, offers a distinction of another sort: and that of land animals, there are some kinds that respire by lungs, as quadrupeds, and others that have no such kind of respiration; that some are winged, and others wingless; that some possess proper blood, while others are exsanguineous; that some produce their young by eggs, and these he named oviparous, while others bring them forth naked, and these he called viviparous; that quadrupeds, again, may, perhaps, be distinguished by the make of the foot, as being of three kinds, undivided, cloven, and digitated, or severed into toes or claws.f

These, indeed, were mere hints, and only intended as such; but they were truly valuable and important; for they roused zoologists to that general comparison of animal with animal, which could not fail of very essentially advancing the cause of natural history; and have, in different degrees, laid the foundation of almost every methodical arrangement which has since been offered to the world.

To run over a list of these arrangements would be equally useless and jejune. The writers who have chiefly signalized themselves in this department, are Gesner, Aldrovandi, Johnston, Ray, Linnaeus, Klein, Lacepede, Blumenbach, and Cuvier; and in particular sections of it, Lamarck, Bloch, Fabricius, Latreille, and Brogniart; all of whom have flourished since the middle of the sixteenth century; most of whom have contributed something of importance to a scientific method of studying and distributing animals; and the most celebrated of whom are Ray, Linnaeus, and Cuvier.

The system of Ray is derived, in its first outlines, from that recommendation of Aristotle, which suggests an attention to the different structures of different descriptions of animal life; and his observation, that one of these

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differences consists in their possessing lungs and a sanguineous system, or their being destitute of lungs and exsanguineous.

The Linnaean method is, for the most part, built upon this general arrangement of Mr. Ray, especially in regard to quadrupeds; it is, however, an extension of it, and certainly an improvement. That of M. Cuvier, in its subordinate division, is founded upon both these; but in its primary and leading distinctions, upon the nervous or sensorial, instead of upon the respiratory and sanguineous systems; all animals, upon M. Cuvier's scheme, being primarily divided into vertebrated and invertebrated; those furnished with a back-bone, or vertebral chain, for the purpose of enclosing the spinal marrow, and those destitute of such a chain: the secondary sections, consisting of vertebrated animals with warm blood, and vertebrated animals with cold blood; invertebrated animals with blood-vessels, and invertebrated animals without blood-vessels.

All these, under his last modification, which is that subjoined to his Lectures on Comparative Anatomy,* are regarded as embracing nine distinct classes; as, I. Mammals; and, II. Birds, which belong to the warm-blooded vertebral division. III. Amphibials; and, IV. Fishes, which belong to the coldblooded vertebral division; and the five following, which fill up the division of invertebral animals: V. Molluscous, soft-bodied marine animals, or mostly marine animals, as oysters, limpets, whelks, cuttle-fish, pipe-worms or shipworms, defended by a testaceous covering. VI. Crustaccous; as crabs, various lobsters, shrimps, sea-spiders, and the monoculus tribes. VII. inSects; being all those ordinarily so denominated. VIII. Worms ; embracing, along with those commonly so called, leeches, and various sea-worms with bristles on the sides of the body, as aphrodites, terebels or naked ship-worms, serpules, amphitrites, nereids, tooth-shells. IX. Zoophytes; the term being used very extensively, so as to include, not only all the zoophytes or plant-like animals of Linnaeus and other naturalists, but all their infusory, wheel, or microscopic animals; their medusas or sea-nettles, actinias or anemonies, and other efflorescent worms, urchins, and star-fishes; and thus largely infringing on the molluscous order of prior arrangements.

Many of these classes have inferior sections and subsections, under which the genera that appertain to them are respectively marshalled. But in a general outline it is not necessary to follow up the arrangement more minutely.

The common classification of zoological writers of the present day is still that of Linnaeus; and as such, it is that which I shall regularly follow up in the remainder of the present study, as being best adapted to popular purposes. It is probable, however, that the classification of Cuvier will ultimately take the lead of it; it is somewhat more abstruse, but considerably more definite; and offers a noble specimen of scientific ingenuity, applied to one of the noblest branches of scientific study; and I shall hence advert to this classification as we proceed, for a comparison with that of the justly celebrated Swedish naturalist.

The Linnaean system of zoology divides all animals into six classes, and each class into a definite number of orders; every order consisting of an indefinite number of kinds or genera; and every kind or genus of an indefinite number of species: the individuals in each species being perhaps innumerable. The six classes are as follows: I. mammals, or suckling animals ; II. birds; III. amphibials; IV. fishes; V. insects; VI. worms.

These may be contemplated either in an ascending or a descending scale. As we have begun with brute matter, and have progressively pursued it from a shapeless mass to mineral crystallization, from mineral crystallization vegetable organization, and from vegetable organization to animal/P011"neity, it will be most congruous still to continue in the same direction, and to commence with the lowest class constituting the worm tribes.

I. Worms, in the Linnaean vocabulary, is a term of far more extensi

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import than in its popular signification; and the reason of this we shall perceive as we proceed. They include all animals below the rank of insects, and are classically characterized, as being mostly without distinct head and without feet; the most prominent organ being their tentacles or feelers. The class is divided into Five Orders; intestinal, molluscous, testaceous, zoophytic, and infusory.

The First Order or Intestinal, with a few exceptions which are found in the waters, consists of animals that are uniformly traced in the bowels of the earth, or of other animals; whence, indeed, their ordinal name. They are ordinarily characterized as being simple, naked animals, without limbs. I shall instance as examples of it, the ascaris, which is found so frequently in the intestinal tube of mankind, in the species of maw or thread-worm, and round-worm: the taenia, which comprises among many others the two species of tape-worm and hydatid; and the filaria or Guinea-worm, which inhabits both the Indies, and is frequent in the morning dew; at which time it winds unperceived into the naked feet of slaves, or other menials, and creates the most troublesome itchings, frequently accompanied with inflammation and fever. The only method of extracting it is to draw it out cautiously by means of a piece of silk tied round its head as it peeps from the inflamed surface; for if, in consequence of too much straining, the animal should break, the part remaining under the skin will still survive, grow with redoubled vigour, and occasionally augment the local inflammation to such an extent, as to prove fatal. It is often twelve feet long, though not larger in diameter than a horse-hair.

The next intestinal worm at which it is worth while to throw a glance as we pass on, is the fasciola or fluke, principally known from one of its species being found in large abundance in the liver of sheep during the disease called the rot, but whether the cause or the result of this disease has never yet been sufficiently ascertained. There are other species of this animal found in the stomach, intestines, or liver of various other animals, and occasionally of man himself. The fasciola is hermaphrodite and oviparous.

The gordius or hair-worm is chiefly worthy of notice as being supposed, in one of its species, if incautiously handled, to inflict a bite at the end of the fingers, and produce the complaint called a whitlow. It inhabits soft stagnant waters, is from four to six inches long, and is almost perpetually twisting itself into various contortions and knots.

The last two kinds I shall enumerate under this order of worms are, the lumbricus or earth-worm, including the dew-worm and the slug; and the hirudo or leech, both of them too well known under several species to require any farther remark in the present rapid outline. This order includes nearly the whole of M. Cuvier's class of worms, with the exception of his sea-worms, already adverted to.

The Second Order of the Worm Class is denominated Mollusca, Molluscous, or Soft-bodied Shell-worms; and consists, for the most part, of similar animals to those found in snail, oyster, nautilus, and other shells, but without a shelly defence: and hence, in their ordinal character, they are described as simple animals, naked, but furnished with limbs, of some kind or other. By this last mark they are distinguished from the preceding, or intestinal order, which, as already observed, consists of simple animals, naked and destitute of limbs. To place the order more immediately before you, I shall select a few examples from those animals that are most familiar to us, or are most remarkable for the singularity of their structure or other properties.

The limax or slug is one of the most simple animals that belong to this order: its only limbs are four feelers, tentacles, or horns, as they are commonly called, situate above the mouth, with a black dot at the tip of each of the larger ones, which is supposed to be an eye, though this point has not been fully established. Another genus of molluscous worms is the terrabella; one species of which is the ship-worm, with an oblong, creeping, naked body, and numerous capillary feelers about the mouth, from four to six inches in length. It is sometimes enclosed in a testaceous or shelly tube, and is then

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