From other causes, such as imperfect descriptions or drawings, may many animals actually existing have ac quired the reputation of fabulous beings in modern times. Thus the hyaena has a real existence, though its back is not formed of one bone, and though it does not change its sex every year, as Pliny was informed. The unicorn is, however, the animal, among all those, which has led to most inquiry, and has longest stood its ground. It is not long since it was said to have been seen during the jour ney of some of our own countrymen in 'Tibet. The obstinacy, or perseverance, on this point, has been con siderable. A drawing is now in our possession, which a native himself the Marquis of Hastings, as taken from an animal that he had himself seen. It is palpably, however, imaginary, or certainly not drawn from nature; although not copied from that Persian work, " The Wonders of the World," which is the origin of all our modern figures of this animal. With respect to the unicorn of the ancients, Cuvicr thinks that they have described the Oryx ; and that the Indian ass is the rhino ceros ; that they possibly also described some other ani mals, investing them, at the same time, with imaginary characters. In most cases the drawings which represent single-horned animals are merely such, because they are the produce of bad artists or savages, who had not the the talent, or did not sec the necessity, of representing both the sides of an animal at once.
Camper properly remarks, that as the Oryx is a ru minant animal, it must have had a suture in the frontal bone, and could not therefore have carried one horn. In respect to every one of the characters of this antelope, except that of the single horn, they agree sufficiently well with the description of the ancients, and with the draw ings of the hieroglyphics; its height resembling that of the ox, and its body being shaped like a stag; while the horns are straight, and as sharp and hard almost as if they had been made or);' iron.
Cuvier equally thinks that no large species remain to be discovered in America, because no new ones have been found within these last 150 years. All the most noted are described in the works of Hernandez and Har grave; the musk ox was distinguished by Pennant. The cloven footed horse of Molina is considered to he fabulous. He considers it impossible that the Mastodon and Mega therium should still be alive and unknown, as they must have been discovered by sonic of the numerous tribes of hunters that are dispersed over this great continent; while he also thinks that opinion strengthened by the uniform opinions of the natives, that they had been destroyed by the great spirit, to prevent them from extirpating the human race ; a fable intended to account for their being no longer found. Hence he concludes, as had been done
before, that none of those animals which he has deter mined to be extinct are now existing.
The correspondence between fossil and existing plants is, as we have already seen, a very obscure subject. On general principles, it is easy and not unreasonable to ima gine, that all the ancient vegetables had been destroyed; whether the same genera or species were repeated or not at a subsequent period. While the inhabitants of the waters might have escaped the effects of those revolutions which changed the face of the globe, it is difficult to con ceive that those which occupied the dry land should not have been exterminated. The only places, at least, in which we know of fossil plants among those strata which are not of the most recent origin. are the coal series and the lias ; and where they have thus been buried, it is probable that even their germs must have been for efer obliterated. Whether any portions of dry land escaped TT these changes, we have no means of discovering; and on general principles, therefore, we have not the power of conjecturing whether there are present individuals or genera resembling those of former days. In the fresh water, or in the upper and recent marine deposits, such as,the blue clay, many vegetable remains are known to exist ; and as in the same situations existing animals are found, it is not improbable that these may often be the fragments of vegetables now flourishing on our own earth; as it is tolerably certain that the revolutions which buried them were of a very partial nature.
But no evidence on this subject can be derived, as in animal remains, from examination of the specimens; as the parts are too much destroyed and detached to admit of the requisite investigations. Certain general analogies have, it is true, been established; such as in the coal strata, between the remains there found, and modern reeds, ferns, and other plants, the produce of intertropical climates. But this subject has scarcely yet been investigated suf ficiently ; and unless the researches now in progress shall prove more successful than the past have been, we shall probably for ever remain in doubt respecting the identity of any lost and existing species, if even corresponding genera should be ascertained.
On the Extinction of Fossil Genera and Species.
The extinction of genera or species in fossil bodies is only part of the present inquiry ; and as its probability or otherwise, on general principles, has already been dis cussed, it only remains to establish the fact itself by evidence, if possible; and to see what explanation, short of one so theoretical as a general system of revolutions in the globe, can be given of it.