GEORGES CUVIER
Georges Cuvier was born Aug. 24, 1769, at Montbéliard, France. He had a brilliant academic career at Stuttgart Academy, and in 1795, at the age of twenty-six, he was appointed assistant professor of comparative anatomy at the Museum d'Histoire Naturelle in Paris, and was elected a member of the National Institute. From this date onwards to his death in 1832, his scientific industry was remarkable. Both as zoologist and palæontologist he must be regarded as one of the greatest pioneers of science. He filled many important scientific posts, including the chair of Natural History in the Collège de France, and a professorship at the Jardin des Plantes. In 1808 he was made member of the Council of the Imperial University; and in 1814, President of the Council of Public Instruction. In 1826 he was made grand officer of the Legion of Honour, and five years later was made a peer of France. The "Discours sur les Révolutions de la Surface du Globe," published in 1825, is essentially a preliminary discourse to the author's celebrated work, "Recherches sur les Ossemens fossiles de Quadrupèdes." It is an endeavour to trace the relationship between the changes which have taken place on the surface of the globe and the changes which have taken place in its animal inhabitants, with especial reference to the evidence afforded by fossil remains of quadrupeds. "It is apparent," Cuvier writes, "that the bones of quadrupeds conduct us, by various reasonings, to more precise results than any other relics of organised bodies." The two books together may be considered the first really scientific palæontology.
I.—Effects of Geological Change
My first object will be to show how the fossil remains of the terrestrial animals are connected with the theory of the earth. I shall afterwards explain the principles by which fossil bones may be identified. I shall give a rapid sketch of new species discovered by the application of these principles. I shall then show how far these varieties may extend, owing to the influence of the climate and domestication. I shall then conceive myself justified in concluding that the more considerable differences which I have discovered are the results of very important catastrophes. Afterwards I shall explain the peculiar influence which my researches should exercise on the received opinions concerning the revolutions of the globe. Finally, I shall examine how far the civil and religious history of nations accords with the results of observation on the physical history of the earth.
When we traverse those fertile plains, where tranquil waters cherish, as they flow, an abundant vegetation, and where the soil, trod by a numerous people, adorned with flourishing villages, rich cities, and superb monuments, is never disturbed save by the ravages of war, or the oppression of power, we can hardly believe that Nature has also had her internal commotions. But our opinions change when we dig into this apparently peaceful soil, or ascend its neighboring hills. The lowest and most level soils are composed of horizontal strata, and all contain marine productions to an innumerable extent. The hills to a very considerable height are composed of similar strata and similar productions. The shells are sometimes so numerous as to form the entire mass of the soil, and all quarters of the globe exhibit the same phenomenon.
The time is past when ignorance could maintain that these remains of organised bodies resulted from the caprice of Nature, and were productions formed in the bosom of the earth by its generative powers; for a scrupulous comparison of the remains shows not the slightest difference between the fossil shells and those that are now found in the ocean. It is clear, then, that they inhabited the sea, and that they were deposited by the sea in the places where they are now found; and it follows, too, that the sea rested in these places long enough to form regular, dense, vast deposits of aquatic animals.
The bed of the sea, accordingly, must have undergone some change either in extent or situation.
Further, we find under the horizontal strata, inclined strata. Thus the sea, previously to the formation of the horizontal strata, must have formed others, which have been broken, inclined, and overturned by some unknown causes.
More than this, we find that the fossils vary with the depth of the strata, and that the fossils of the deeper and more ancient strata exhibit a formation proper to themselves; and we find in some of the strata, too, remains of terrestrial life.
The evidence is thus plain that the animal life in the sea has varied, and that parts of the earth's surface have been alternately dry land and ocean. The very soil, which terrestrial animals at present inhabit has a history of previous animal life, and then submersion under the sea.
The reiterated irruptions and retreats of the sea have not all been gradual, but, on the contrary, they have been produced by sudden catastrophes. The last catastrophe, which inundated and again left dry our present continents, left in the northern countries the carcasses of large quadrupeds, which were frozen, and which are preserved even to the present day, with their skin, hair and flesh. Had they not been frozen the moment they were killed, they must have putrefied; and, on the other hand, the intense frost could not have been the ordinary climatic condition, for they could not have existed at such low temperatures. In the same instant, then, in which these animals perished the climate which they inhabited must have undergone a complete revolution.
The ruptures, the inclinations, the overturnings of the more ancient strata, likewise point to sudden and violent changes.
Animal life, then, has been frequently disturbed on this earth by terrific catastrophes. Living beings innumerable have perished. The inhabitants of the dry land have been engulfed by deluges; and the tenants of the water, deserted by their element, have been left to perish from drought.
Even ancient rocks formed or deposited before the appearance of life on the earth show signs of terrific violence.
It has been maintained by some that the causes now at work altering the face of the world are sufficient to account for all the changes through which it has passed: but that is not so. None of the agents Nature now employs—rain, thaw, rivers, seas, volcanoes—would have been adequate to produce her ancient works.
To explain the external crust of the world, we require causes other than those present in operation, and a thousand extraordinary theories have been advanced. Thus, according to one philosopher, the earth has received in the beginning a uniform light crust which caused the abysses of the ocean, and was broken to produce the Deluge. Another supposed the Deluge to be caused by the momentary suspension of the cohesion of minerals.
Even accomplished scientists and philosophers have advanced impossible and contradictory theories.
All attempts at explanation have been stultified by an ignorance of the facts to be explained, or by a partial survey of them, and especially by a neglect of the evidence afforded by fossils. How was it possible not to perceive that the theory of the earth owes its origin to fossils alone? They alone, in truth, inform us with any certainty that the earth has not always had the same covering, since they certainly must have lived upon its surface before they were buried in its depths. If there were only strata without fossils, one might maintain that the strata had all been formed together. Hitherto, in fact, philosophers have been at variance on every point save one, and that is that the sea has changed its bed; and how could this have been known except for fossils?
From this consideration I was led to study fossils; and since the field was immense I was obliged to specialise in one department of fossils, and selected for study the fossil bones of quadrupeds. I made this selection because only from a study of fossil quadrupeds can one hope to ascertain the number and periods and contents of irruptions of the sea; and because, since the number of quadrupeds is limited, and most quadrupeds known, we have better means of assuring ourselves if the fossil remains are remains of extinct or extant animals. Animals such as the griffin, the cartazonon, the unicorn, never lived, and there are probably very few quadrupeds now living which have not been found by man.
But though the study of fossil quadruped be enlightening, it has its own special difficulties. One great difficulty arises from the fact that it is very rare to find a fossil skeleton approaching to a complete state.
Fortunately, however, there is a principle in comparative anatomy which lessens this difficulty. Every organised being constitutes a complete and compact system with all its parts in mutual correspondence. None of its parts can be changed without changing other parts, and consequently each part, taken separately, indicates the others.
Thus, if the intestines of an animal are made to digest raw flesh, its jaws must be likewise constructed to devour prey, its claws to seize and tear it, its teeth to rend it, its limbs to overtake it, its organs of sense to discern it afar. Again, in order to enable the jaw to seize with facility, a certain form of condyle is necessary, and the zygomatic arch must be well developed to give attachment to the masseter muscle. Again, the muscles of the neck must be powerful, whence results a special form in the vertebræ and the occiput, where the muscles are attached. Yet again, in order that the claws may be effective, the toe-bones must have a certain form, and must have muscles and tendons distributed in a certain way. In a word, the form of the tooth necessitates the form of the condyle, of the shoulder-blade, and of the claws, of the femur, and of all the other bones, and all the other bones taken separately will give the tooth. In this manner anyone who is scientifically acquainted with the laws of organic economy may from a fragment reconstruct the whole animal. The mark of a cloven hoof is sufficient to tell the form of the teeth and jaws and vertebræ and leg-bones and thigh-bones and pelvis of the animal. The least fragment of bone, the smallest apophysis, has a determinative character in relation to the class, the order, the genus, and species to which it may belong. This is so true that, if we have only a single extremity of bone well preserved, we may, with application and a skilful use of analogy and exact comparison, determine all those points with as much certainty as if we were in possession of the entire animal. By the application of these principles we have identified and classified the fossil remains of more than one hundred and fifty mammalia.
II.—What the Fossils Teach
An examination of the fossils on the lines I have indicated shows that out of one hundred and fifty mammiferous and oviparous quadrupeds, ninety are unknown to present naturalists, and that in the older layers such oviparous quadrupeds as the ichthyosauri and plesiosauri abound. The fossil elephant, the rhinoceros, the hippopotamus, and the mastodons are not found in the more ancient layers. In fact, the species which appear the same as ours are found only in superficial deposits.
Now, it cannot be held that the present races of animals differ from the ancient races merely by modifications produced by local circumstances and change of climate—for if species gradually changed, we must find traces of these gradual modifications, and between the palæotheria and the present species we should have discovered some intermediate formation; but to the present time none of these have appeared.
Why have not the bowels of the earth preserved the monuments of so remarkable a genealogy unless it be that the species of former ages were as constant as our own, or at least because the catastrophe that destroyed them had not left them time to give evidence of the changes?
Further, an examination of animals shows that though their superficial characteristics, such as colour and size, are changeable, yet their more radical characteristics do not change. Even the artificial breeding of domestic animals can produce only a limited degree of variation. The maximum variation known at the present time in the animal kingdom is seen in dogs, but in all the varieties the relations of the bones remain the same and the shape of the teeth undergoes no palpable change.
I know that some naturalists rely much on the thousands of ages which they can accumulate with a stroke of the pen; but there is nothing which proves that time will effect any more than climate and a state of domestication. I have endeavoured to collect the most ancient documents of the forms of animals. I have examined the engravings of animals including birds on the numerous columns brought from Egypt to Rome. M. Saint Hilaire collected all the mummies of animals he could obtain in Egypt—cats, ibises, birds of prey, dogs, monkeys, crocodiles, etc.—and we cannot find any more difference between them and those of the present day than between human mummies of that date and skeletons of the present day.
There is nothing, then, in known facts which can support the opinion that the new genera discovered among fossils—the palæotheria, anoplotheria, megalonyces, mastodontes, pterodactyli, ichthyosauri, etc.—could have been the sources of any animals now existing, which would differ only by the influence of time or climate.
As yet no human bones have been discovered in the regular layers of the surface of the earth, so that man probably did not exist in the countries where fossil bones are found at the epoch of the revolutions which buried these bones, for there cannot be assigned any reason why mankind should have escaped such overwhelming catastrophes, or why human remains should not be discovered. Man may have inhabited some confined tract of country which escaped the catastrophe, but his establishment in the countries where the fossil remains of land animals are found—that is to say, in the greatest part of Europe, Asia, and America—is necessarily posterior not only to the revolutions which covered these bones, but even to those which have laid open the strata which envelop them; whence it is clear that we can draw neither from the bones themselves nor from the rocks which cover them any argument in favour of the antiquity of the human species in these different countries. On the contrary, in closely examining what has taken place on the surface of the globe, since it was left dry for the last time, we clearly see that the last revolution, and consequently the establishment of present society, cannot be very ancient. An examination of the amount of alluvial matter deposited by rivers, of the progress of downs, and of other changes on the surface of the earth, informs us clearly that the present state of things did not commence at a very remote period.
The history of nations confirms the testimony of the fossils and of the rocks. The chronology of none of the nations of the West can be traced unbroken farther back than 3,000 years. The Pentateuch, the most ancient document the world possesses, and all subsequent writings allude to a universal deluge, and the Pentateuch and Vedas and Chou-king date this catastrophe as not more than 5,400 years before our time. Is it possible that mere chance gave a result so striking as to make the traditional origin of the Assyrian, Indian, and Chinese monarchies agree in being as remote as 4,000 or 5,000 years back? Would the ideas of nations with so little inter-communication, whose language, religion, and laws have nothing in common, agree on this point if they were not founded on truth? Even the American Indians have their Noah or Deucalion, like the Indians, Babylonians, and Greeks.
It may be said that the long existence of ancient nations is attested by their progress in astronomy. But this progress has been much exaggerated. But what would this astronomy prove even if it were more perfect? Have we calculated the progress which a science would make in the bosom of nations which had no other? If among the multitude of persons solely occupied with astronomy, even then, all that these people knew might have been discovered in a few centuries, when only 300 years intervened between Copernicus and Laplace.
Again, it has been pretended that the zodiacal figures on ancient temples give proof of a remote antiquity; but the question is very complicated, and there are as many opinions as writers, and certainly no conclusions against the newness of continents and nations can be based on such evidence. The zodiac itself has been considered a proof of antiquity, but the arguments brought forward are undoubtedly unsound.
Even if these various astronomical proofs were as certain as they are unconvincing, what conclusion could we draw against the great catastrophe so indisputably demonstrated? We should only have the right to conclude that astronomy was among the sciences preserved by those persons whom the catastrophe spared.
In conclusion, if there be anything determined in geology, it is that the surface of our globe has been subjected to a revolution within 5,000 years, and that this revolution buried the countries formerly inhabited by man and modern animals, and left the bottom of the former sea dry as a habitation for the few individuals it spared. Consequently, our present human societies have arisen since this catastrophe.
But the countries now inhabited had been inhabited before, as fossils show, by animals, if not by mankind, and had been overwhelmed by a previous deluge; and, indeed, judging by the different orders of animal fossils we find, they had perhaps undergone two or three irruptions of the sea.