« PrécédentContinuer »
perfect as the most recent. There is no such thing as equivocal generation. One species of animals never produces another. The turtles and sauri of the preAdamite world, might have multiplied in their fens and shallow waters to the end of time, they never would have produced the mammoth or the megatherium, the lion or the tiger. None of these would ever have produced a human being. This is well understood by Mr Combe. He distinctly and correctly states, that each new race of plants or animals was the result of a separate act of creation; and he states, moreover, in the very outset of his work, the general fact, that every creature, and every physical object," has received its own definite constitution.'
* In evidence of what I have stated on this point, I may refer to the following passage in Cuvier : "The following objection has already been started against my conclusions, Why may not the presently existing races of land quadrupeds be mere modifications or varieties of those ancient races, which we now find in the fossil state, which modifications may have been produced by change of climate and other local circumstances, and since raised to the present excessive difference, by the operation of similar causes during a long succession of ages?
"This objection may appear strong to those who believe in the indefinite possibility of change of forms in organized bodies, and think that, during a succession of ages, and by alterations of habitudes, all the species may change into each other, or one of them give birth to all the rest. Yet, to those persons, the following answer may be given from their own system: if the species have changed by degrees, as they assume, we ought to find traces of this gradual modification. Thus, between the Palæotherium, and the species of our own days, we should be able to discover some intermediate forms, and yet no such discovery has ever been made. Since the bowels of the earth have not preserved monuments of this strange genealogy, we have a right to conclude, that the ancient and now extinct species were as permanent in their forms and characters, as those which exist at present; or, at least, that the catastrophe which destroyed them did not leave sufficient time for the production of the changes that are alleged to have taken place."†
After making some observations on the varieties produced in animals by domestication, and by the mixture of breeds effected by the con+ Cuvier's Essay on the Theory of the Earth, translated by Jameson, 4th Ed.
This being the case with regard to the successive races of plants and animals, in the ages preceding the creation of man, as far as can be discovered from the researches of geologists, what is our experience respecting those species with which the earth is furnished at present? Do we find that the different genera and species of plants and animals now on the earth contain, each within itself, the elements of improvement? Are the trees of the forest now of loftier growth, and more splendid dimensions, than those which originally covered the mountains of our globe? Does the cedar now rear its umbrageous head in greater magnificence than it did in the days of Ezekiel, who describes it" with fair branches and with a shadowing shroud, and of an high stature, and having its top among the thick boughs? The fir trees were not like his boughs, and the chestnut trees were not like his branches, nor any tree in the garden of God like unto him in beauty." Do we not know, on the contrary, that the glory of Lebanon is fallen, and that in the whole of that mountain range, once covered with the most magnificent forests, a few scattered remnants are all that remain, without the least prospect that its pristine honours will ever be restored? Do we not find the same in all countries originally covered with wood, that the existing trees are a dwarfish and insignificant race, when compared with those giants of the forest, of which the wrecks and ruins. are here and there to be observed, or which have been
trivance, and under the influence of man, and shewing that all these varieties are perfectly insignificant, and never amount to an alteration in the original and proper specific type, Cuvier comes to the conclusion, "that animals have certain fixed and natural characters, which resist the effects of every kind of influence, whether proceeding from natural causes or human interference; and we have not the smallest reason to suspect, that time has any more effect upon them than climate."*
Theory of the Earth, p. 122.
found preserved in an entire state in the marshes, or buried fathoms deep in soil, the accumulation of ages?
But to come nearer the point at issue: Is there the smallest reason to believe that any existing species of animals has become improved or advanced in the scale of perfection, by virtue of a principle of progression inherent in its own nature, and which time has evolved and brought to maturity? Does the lion now traverse the burning desert with a more lordly step, or shake the wilderness with a more appalling roar, than he did in the days of Moses, who refers to him as the type of every thing that is strong and terrible, or of Solomon, who compares his roaring to "the wrath of a king ?" Does the horse exhibit now more magnificent qualities, than those ascribed to him in the Book of Job? And has man, with all his boasted wisdom and skill, "given the horse strength, has he clothed his neck with thunder?"
Does the hawk now fly more swiftly, or does the eagle mount up with a stronger wing, or make her nest higher in the rock, than in ages long past? Are the goodly wings of the peacock adorned with more splendid colours, or are the feathers of the ostrich larger and finer, or her flight swifter, than in the days of Job? "What time she lifteth up herself on high, she scorneth the horse and his rider."
I refer to the above passages, merely as occurring in the most ancient writings in the world, to shew that the productions of nature described in them, possessed, upwards of three thousand years ago, the same qualities as they do now, and that no improvement or alteration ever has taken place in these qualities. In the absence of all evidence to the contrary, this might be quite sufficient; but we are not left to mere negative evidence, or the descriptions of ancient writers on this important point. We have the positive evidence of undisputed facts, that
the existing races of animals have undergone no change as far back as it is possible to trace them. For this, we have the express authority of Baron Cuvier, whose judgment, on a point of this kind, will not be disputed.*
We have, therefore, every kind of evidence, positive and negative, for asserting, that neither in the vegetable nor in the animal creation is there any such thing as a natural state of progression; and that no race or species
* "I have endeavoured," he says, "to collect all the ancient documents respecting the forms of animals, and there are none equal to those furnished by the Egyptians, both in regard to their antiquity and abundance. They have not only left us representations of animals, but even their identical bodies embalmed and preserved in the catacombs.
I have examined, with the greatest attention, the engraved figures of quadrupeds and birds upon the numerous obelisks brought from Egypt to ancient Rome, and all these figures, one with another, have a perfect resemblance to their intended objects, such as they are still in our days. On examining the copies made by Kirker and Zoega, we find, that without preserving every trait of the original in its utmost purity, they have yet given us figures which are easily recognized. We readily distinguish the ibis, the vulture, the owl, the falcon, the Egyptian goose, the lapwing, the land-rail, the asp, the Egyptian hare with its long ears, even the hippopotamus; and among the numerous remains engraved in the great work on Egypt, we sometimes observe the rarest animals, the algazel for instance, which was known in Europe only a few years ago. My learned colleague, M. Geoffroy Saint Hilaire, convinced of the importance of this research, carefully collected, in the tombs and temples of Upper and Lower Egypt, as many mummies of animals as he could procure. He has brought home the mummies of cats, ibises, birds of prey, dogs, monkeys, crocodiles, and the head of a bull; and after the most attentive and detailed examination, not the smallest difference is to be perceived between these animals and those of the same species which we now see, any more than between the human mummies and the skeletons of men of the present day. Some slight differences are discoverable between ibis and ibis, just as we now find differences in the descriptions of naturalists; but I have removed all doubts on that subject, in a memoir on the ibis of the ancient Egyptians, in which I have clearly shewn that this bird is precisely the same in all respects, at present, that it was in the days of the Pharaohs. I am aware that in these I only cite the monuments of two or three thousand years back; but this is the most remote antiquity to which we can resort in such a case.'
Theory of the Earth, ut sup. p. 123.
of either has ever, as a species, improved itself, or shewn any symptom of "possessing within itself the elements of improvement." Nature is constant, as Mr Combe is fond of observing, and her rules admit of no exceptions, and here there is no exception in any class of her productions; from the cedar in Lebanon to the hyssop that springeth out of the wall, or from the leviathan or elephant down to the lowest zoophite or coral insect, none have ever improved themselves, or given birth to improved or superior races. None of these has, as a species, been "constituted on the principle of a progressive system, as the acorn in reference to the oak."
I assume it, then, as a general law, that throughout the whole of organized existence, each species, at its first creation, receives a distinct and definite constitution, which it transmits, without the capacity of improvement, through all succeeding generations. This is not only consistent with all the known facts, but is likewise conformable to what might be expected a priori; for how could we suppose that the first of a species, coming directly from the hand of the Almighty workman, who contrived and formed all its different parts, could be less perfect than those which were produced afterwards by its means? The reverse of this appears at first sight much more probable; and accordingly, in certain cases, we find it to be true.
Although each species preserves its original type unaltered, and never can by possibility acquire qualities of a higher nature, yet individuals of the species, or even the whole individuals of a species, from accidental circumstances, from want of proper food, or from being placed in situations not in harmony with their nature, may be, and often have been found to degenerate, and fall below the original standard of their race. But there is throughout all animated nature a certain spring.