On

everywhere cover the remains of an earlier creation, of a ruined nature. the one hand immense masses of shells and of other marine bodies are found at great distances from any sea, at heights to which no sea could now attain, and from thence have been derived the first facts in support of all those traditions of deluges preserved among so many tribes of mankind. On the other hand, the large bones discovered from time to time in the bowels of the earth, in the caverns of the mountains, have given rise to those other popular traditions, not less diffused and not less ancient, of races of giants which have peopled the world in its first ages.

The traces of the revolutions of our globe have, therefore, at all times impressed the minds of men, but they long impressed them in vain, and only with a fruitless astonishment. For a long time, indeed, ignorance was carried to such a point that an opinion very nearly universal, and I speak not here of popular opinion, but of the opinion of savants and philosophers, regarded the stones charged with the impressions of animals or plants and the shells found in the earth as sports of nature. "It was necessary," says Fontenelle, "that a common potter, who knew neither Latin nor Greek, should dare, about the end of the sixteenth century, to say in Paris, and in the face of all the doctors, that the fossil shells were real shells, deposited heretofore by the sea in the places where they were then found; that animals had impressed on the figure-bearing stones all their different figures, and that he should boldly defy the whole school of Aristotle to contest his proofs."

This potter was Bernard Palissy, renowned for having made barely a first step in a route traversed since then by so many great men, and which has conducted them to such astonishing discoveries. In truth, the ideas of Palissy could scarcely be expected to attract notice at the epoch when they appeared, and it was not till about a century later-that is to say, toward the close of the seventeenth century-that they began to revive, and, again to recall an expression of Fontenelle's, "to thrive in the world as they deserved to do." But from that time such was the activity put forth, both in collecting the remains of organized bodies buried beneath the surface of the earth and in studying the strata which contain them, and under this twofold relation so rapidly were significant facts multiplied, that some bold and perspicacious minds were not afraid even then to combine them in generalizations and attempt to ascend to their causes. It was, in effect, at the close of the seventeenth century, and during the first half of the eighteenth, that the celebrated systems of Burnet, Leibnitz, Woodward, Whiston, and Buffon made their appearance--all of them premature and more or less erroneous, no doubt, but productive of this advantage, that they accustomed the human intellect to contemplate these astounding phenomena in a philosophic spirit, and not to shrink from measuring itself against them.

Another advantage, of even greater moment, was, that all these systems, by exciting a strong interest, presently drew together from all parts observations at once more numerous, precise and complete; the first effect of which was to overturn all that was imaginary and absurd in those systems; and the second, to found on their ruins the true theory, the positive history of the earth.

The eighteenth century, which advanced so rapidly in so many directions, perhaps witnessed nothing more rapid than the progress of the science of which we are speaking. The same century which in its first moiety had seen all the systems just spoken of, structures as brilliant as frail, either rise or fall, this century saw, in its second, the first foundations of the enduring monument which was to succeed them, cast by the hands of a Pallas, a Deluc, a de Saussure, a Werner, a Blumenbach, a Camper, and others who so ably seconded them.

Among these advances it is proper that I should here especially recall those which relate to the fossil remains of organized bodies. It was these remains, in effect, subsisting witnesses as they are of so many revolutions, so many violent subversions sustained by the globe, which had given rise to the first hypothesis

of the fantastic geology; and it was again these remains which, in the hands of M. Cuvier, furnished the results the most evident and the laws best ascertained of the positive geology. The researches of M. Cuvier were principally directed to the fossil bones of quadrupeds-a part of the animal kingdom till then little studied under this new point of view, but the study of which was calculated to lead to consequences much more precise and decisive than that of any other class.

I have already mentioned the large fossil bones discovered at different epochs, and the absurd ideas of giants, which were renewed at each discovery which was made of them. Daubenton was the first to overthrow all these ideas; it was he who first applied comparative anatomy to the determination of the remains in question; but, as he himself avows, this science was as yet far from being sufficiently advanced to furnish, in all cases and with sufficient certainty, the species or genus of animal to which an unknown and isolated bone might appertain, and yet such was the problem to be solved. The memoir in which Daubenton attempted for the first time the solution of this important problem was of the date of 1762.

In 1769 Pallas published his first memoir on the fossil bones of Siberia. It was not without surprise that the demonstration was here seen of the fact that the elephant, the rhinoceros, the hippopotamus-animals which at present live only under the torrid zone-had heretofore inhabited the most northern portions of our continents. The second memoir of Pallas could not but excite still more wonder, for he there reports the fact, which could scarcely seem credible at that time, that a rhinoceros had been found entire in the frozen earth with its skin and flesh-a fact since renewed, as is known to all, in the elephant discovered in 1806 on the shores of the Glacial sea, and so well preserved that dogs and bears devoured its flesh and disputed its remains with one another.

The impulse once communicated by Pallas, the relics of animals of the south were soon found, not only in the countries of the north, but in all the regions of the old as well as new world. Buffon, from these facts, hastened to deduce his hypothesis of the gradual refrigeration of the polar regions and of the successive migration of animals from the north to the south. But the last fact observed by Pallas, and which has just been cited, had already overthrown this assumption. That fact effectually demonstrated, in the most formal manner, that the refrigeration of the globe, far from having been gradual, had, on the contrary, necessarily been sudden, instantaneous, without any gradation; it demonstrated that the same instant which destroyed the animals in question had rendered the country of their habitat glacial; for had they not been frozen as soon as killed it is evident that they could not have descended to us with their flesh and skin and every part in perfect preservation. The hypothesis of gradual refrigeration being thus untenable, Pallas substituted that of an irruption of water coming from the southeast-an irruption which, he maintained, would have transported into the north the animals of India; but this second hypothesis was not more happy than the first, for the fossil animals are very different from those of India, and indeed from all animals now living-a final fact more extraordinary still than all which preceded it, and which it was reserved for M. Cuvier to place in the clearest light.

The fact of an ancient creation of animals entirely distinct from the existing creation, and long since entirely lost, is the fundamental fact on which rest the most evident proofs of the revolutions of the globe. It cannot, therefore, be without interest to observe how the idea of this fact, assuredly the most extraordinary which scientific research has been enabled to discover and to prove, had its first rise, its subsequent development, and final confirmation.

We have seen how, toward the end of the sixteenth century, Bernard Palissy had ventured, first among the moderns, to maintain that the bones, the impressions, the fossil shells, so long regarded as casual freaks of nature, were the

remains of real creatures, the veritable spoils of organized bodies. In 1670 Augustine Scilla renewed the opinion of Palissy and sustained it with vigor. Shortly after, in 1683, Leibnitz lent to it the authority of his name and genius. Finally, from the first half of the eighteenth century, Buffon reproduced it with still more splendor, and directly made it popular.

But are these organized beings, of which innumerable relics are scattered everywhere, the analogues of those which are now living, whether in the places where these relics are found or in others? or have, indeed, their species, their genera, perished? It is here that the difficulty lies, and we may well believe that this difficulty would never have been resolved, at least with complete certainty, as long as the inquiry had been restricted, for example, to the study of fossil shells or of fishes. It would have availed little, in effect, to find new shells, new fishes; we should have been always at liberty to suppose that their species were still living, whether in distant seas or at inaccessible depths. Not so, however, as regards quadrupeds. The number of these is greatly more limited, especially for the larger species, we may count on attaining a knowledge of all of them-how vastly more easy then to satisfy ourselves whether certain unknown bones belong to one of these species still living, or whether they proceed from such as are lost.

This it is which gives to the study of fossil quadrupeds a peculiar importance and to the deductions which may be drawn from it a force which deductions derived from a study of most of the other classes could not possess. Buffon seems to have felt this. It was chiefly on the great fossil bones of Siberia and Canada that he sought to sustain the conjecture (for, in view of the state of comparative anatomy at the time when he wrote, it could be only a conjecture) of certain lost species. Besides, even this conjecture was so imperfectly established in his own mind, at least in relation to quadrupeds, that after having regarded, in his Théorie de la Terre, all the animals to which these extraordinary bones had belonged as lost, he afterwards declared, in his Époques de la Nature, that he no longer recognized more than a single lost species-that which has been called the mastodon—and that all the other bones in question are merely those of the elephant and the hippopotamus.

Camper went much further, as might have been expected, for comparative anatomy had not failed to advance by long strides since the days of Buffon. In 1787, in a memoir addressed to Pallas, Camper boldly enunciates the opinion that certain species have been destroyed by the catastrophes of the globe, and, moreover, sustains it by the first really positive facts, though still very incomplete, which had yet been advanced in its support. Thus, in proportion to the determination of fossil bones has been the progress of the idea of lost animals, and it has always been by the light of comparative anatomy that this progress was accomplished. It was, in effect, this light of comparative anatomy which had been wanting to so many laborious researches of so many naturalists. But it is easy to see that towards the epoch of which I speak, towards the close, namely, of the eighteenth century, everything was prepared for the long-sought solution; that the moment was at hand for some revelation, some complete and definitive result respecting these strange and marvellous phenomena.

The 1st Pluviose, an IV, (February, 1796,) being the day of the first public session held by the National Institute, M. Cuvier read before the assembled body his memoir on the fossil species of the elephant compared with the living species. It was in this memoir that he announced, for the first time, his views on extinct animals. Thus, on the same day when the Institute opened the first of its public sessions, was opened also the career of the greatest discoveries which natural history has made in our age: a singular coincidence, which the history of the sciences should not fail to mark and commemorate.

M. Cuvier had now initiated that brilliant series of researches and labors which occupied him so many years, and which, during the whole time, called

forth renewed surprise and admiration on the part of his contemporaries. In this first memoir he does not confine himself to demonstrating that the fossil elephant is a distinct species from the existing species-that it is a species extinct and lost; he expressly declares that the greatest step which could be made towards the perfection of the theory of the earth, would be to prove that none of those animals whose remains are found dispersed over nearly all points of the globe, any longer exist. He adds that what he then established in regard to the elephant he would soon establish in a not less incontestable manner in regard to the fossil rhinoceros, bear, and deer, all of them species equally distinct from living species, all of them equally lost. Finally he concludes with the following remarkable words, in which he seemed to announce all that he has since discovered: "If it be asked why we find so many remains of unknown animals, while we find none of which it can be said that they belong to species that we know, it will be seen how probable it is that they have all pertained to the creatures of a world anterior to our own; to creatures destroyed by some catastrophe of the globe; to creatures whose place has been filled by those which exist to-day."

Thus the idea of an entire creation of animals anterior to the actual creation, the idea of an entire creation destroyed and lost had at last been fully conceived; and had found an utterance which proved to be a final solution of the doubts which, for a century, had so strongly occupied the human mind.

But, in order to transform into a positive result views thus vast and elevated, it was necessary to assemble from all quarters the remains of the lost animals, to pass them in review, to study them under this new aspect; it was necessary to compare them all, one after the other, with the remains of living animals; and, first of all, it was necessary to create and determine the art itself by which this comparison was to be made.

Now, for a right conception of all the difficulties of this new method, this new art, it is sufficient to remark that the débris of the animals in question, the fossil bones, are almost always isolated and dispersed; that often the bones of several species, and those the most diverse, are mingled in confusion; that almost always these bones are mutilated, broken, reduced to fragments. It was requisite, therefore, to refer each bone to the species to which it pertained; to reconstruct, if possible, the complete skeleton of each species, without omiting any of the pieces which were its own, without intercalating any which were foreign to it. Let us now represent to ourselves this confused intermingling of mutilated and imperfect relics assembled together by M. Cuvier; let us conceive each bone, each portion of a bone, taking its place under his skilful hand, each uniting itself to the bone or portion of bone to which it had pertained; let us observe all these species of animals, destroyed for so many ages, thus rising before us in their various forms, with each character, each attribute restored, and we shall scarcely realize that we are witnessing a simple anatomical operation, but rather a sort of resurrection; nor will it abate anything of the prodigy that it is a resurrection effected at the voice of science and of genius.

I say at the voice of science. The method employed by M. Cuvier for this wonderful reconstruction is, in effect, but the application of the general rules of comparative anatomy to the determination of fossil bones. And these rules themselves are a not less grand, less admirable discovery than the surprising results to which they have led.

It has been seen above how a rational principle, that of the subordination of organs, everywhere applied, everywhere reproduced in establishing the groups of the method, had changed the face of the classification of the animal kingdom. The principle which presided at the reconstruction of lost species is that of the correlation of forms, a principle by means of which each part of an animal may be given by each other part, and the whole animal by a single part. In a mechanism as complex, and yet as essentially a unit as that which constitutes

the animal frame, it is evident that all the parts must necessarily be constructed one with reference to the others, so as to correspond, to adapt themselves to one another, to form, in a word, by their assemblage, one being, one unique system. A single one of these parts, therefore, cannot change its form without necessitating a change in form of all the others. Hence from the form of one part may be deduced the form of all the other parts.

Suppose a carnivorous animal; it will necessarily have the organs of sense and of movement; the claws, teeth, stomach, intestines, adapted for scenting, seizing, tearing, digesting its animal prey, and all these conditions will be rigorously linked with one another; for, if one be wanting, the others would be without effect, without result; the creature could not subsist. Suppose, on the other hand, an herbivorous animal; all this assemblage of conditions will have changed. The teeth, the feet, the stomach, the intestines, the organs of movement and of sense, will all have assumed new forms, and these new forms will always be proportioned and related one to the others. From the form of a single one of these parts, therefore, from that of the teeth alone, for example, we may infer, and infer with certainty, the form of the feet, that of the jaws, that of the stomach, that of the intestines.

All the parts, all the organs, are deducible, then, one from the other; and such is the rigor, such the infallibility of this deduction, that M. Cuvier has been often known to recognize an animal by a single bone, nay by the facet of a bone; that he has been known to determine unknown genera and species from a few broken bones, and this from such or such a bone taken at random, reconstructing in this way the entire animal from a single one of its parts, and causing it to reappear, as at will, from each of them; results which cannot be recalled without recalling in effect all that admiration, mingled with surprise, which they at first inspired, and which is not yet exhausted.

That precise and rigorous method of distinguishing bones confounded togetherof referring each bone to its species; of reconstructing the entire animal from some of its parts-that method once conceived, it was no longer by isolated species but by groups and masses that these extinct populations, antique monuments of the revolutions of the globe, reappeared. An idea might then be formed not only of their extraordinary appearance, but of the prodigious multitude of their species. It was seen that they comprised creatures of all classes, quadrupeds, birds, reptiles, fishes, down to crustacea, mollusks, and zoophytes. Nor, though I speak here only of animals, does the study of fossil vegetables furnish consequences less curious than those drawn from the animal kingdom. All these organized beings, all these first occupants of the globe, are distinguished by their proper characters, and often by characters the most singular and grotesque.

Among the quadrupeds, for example, we first observe the palæotherium, the anoplotherium, those strange specimens of pachydermata, discovered by M. Cuvier in the environs of Paris, and of which none bearing this peculiar character has descended to our times. Afterwards comes the mammoth, that elephant of Siberia, covered with long hairs and a thick wool; the mastodon, an animal almost as large as the mammoth, and whose teeth, armed with points, long caused it to be regarded as a carnivorous elephant, together with those enormous sloths, the megatherium, the megalonyx, animals of which the existing species do not exceed the size of a dog, while some of those which are lost equalled the largest rhinoceros. Still more extraordinary were the reptiles of those first ages of the world, whether from their gigantic proportions, for there were lizards as large as whales, or from the singularity of their structure, for some had the aspect of the cetacea or marine mammifers, and others the neck and beak of birds, and even a kind of wing.

*Such as the megalosaurus, which was more than 60 feet in length; the ichthyosaurus and the plesiosaurus, whose members are called those of the cetacea; the pterodactyls, which have a very long projection from the anterior extremity, bearing a membrane or sort of wing.