When there afterwards appeared more exact descriptions of an animal having a single horn only, but with several toes, a third species would have been made out, to which they gave the name of _monoceros_. These double references applied to the same species, are more frequent among ancient naturalists, because most of their works which have come down to us were mere compilations; even because Aristotle himself has frequently mingled facts borrowed from others with those which he had observed himself; and because the habit of critical examination was then as little known among naturalists as among historians. From all these reasonings and digressions, it may be fairly concluded, that the large animals of the old continent with which we are now acquainted, were known to the ancients; and that the animals described by the ancients, and which are now unknown, were fabulous. It also follows, that the large animals of the three principal parts of the then discovered world could not have been long in being known to the nations which frequented their coasts. It may also be concluded, that no large species remains to be discovered in America. If there were any, there can be no reason why we should not be acquainted with it; and in fact none has been discovered there during the last hundred and fifty years. The tapir, the jaguar, the puma, the cabiai, the llama, the vicuna, the red wolf, the buffalo or American bison, the ant-eaters, sloths and armadilloes, are as well described by Margrave and Hernandez as by Buffon; it may even be said that they are better, for Buffon has confused the history of the ant-eaters, mistaken the jaguar and red wolf, and confounded the bison of America with the aurochs of Poland. Pennant, it is true, was the first naturalist who clearly distinguished the small musk ox; but it was long before made mention of by travellers. The cloven-footed horse of Molina, has not been described by the early Spanish travellers; but its existence is more than doubtful, and the authority of Molina is too suspicious to authorise our adopting it. It might be possible to characterise more accurately than has been done the different species of deer belonging to America and India; but the case is with respect to these animals as it was among the ancients with respect to the antelopes; it is the want of a good method for distinguishing them, and not of opportunities of seeing them, that has left them so imperfectly known to us. It may, therefore, be said, that the Mouflon of the Blue Mountains is the only American quadruped of any considerable size of which the discovery is altogether modern; and even it is perhaps only an argali that may have crossed upon the ice from Siberia.