It appears to be a matter of history that the horse, which is now so extensively distributed, both in a wild and domestic condition, throughout our continent, was not an inhabitant of it when America was disco-vered by Columbus. It is stated that the first European horsemen were taken to be strange beings—the horse and his rider as one person— by the aborigines of our country. Although this is probably true of the horse, yet recent scientific explorations go to prove that he was an old resident of the New World as well as the Old. Professor F. Holmes, of Charleston, S. C, has discovered several fossil teeth of the horse in a post-pleiocene deposit on the Ashley river, and several teeth have also been exhumed by Col. McChesney, of Troy, N. Y., in his garden. The fossil American horse appears to have been cotemporary with the mastodon ; and some of our naturalists have been speculating on his age, and the unity of the species. Agassiz, who is at the head of our naturalists, does not believe in the unity of the species of men or brutes, and the tendency of the belief of his school of naturalists is, that the horse and man were inhabitants of this continent many thousands of years before this world was created—according to the popular belief—about six thousand years ago. It is all vanity to speculate on these questions of time in regard to natural events, they never can be settled. It would be more wise and profitable for these philosophers to devote attention to the discovery of the cause or causes which led to the extinction of those horses which once inhabited America ; because the same causes which operated then to destroy large numbers of animals—completely annihilated them—may operate again to produce like effects. In our opinion, there was at one period perfect land communication between the Old World and the New. The old tradition that there was once a great, rich and populous country, known to the ancients, and called "Atlantis," which was swallowed up by a storm in the Atlantic ocean, may be founded on fact.