NATURAL HISTORY. 419 



found in association with those of extinct animals, that it is generally admitted 

 once to have been an aboriginal inhabitant. "When I first saw examples of these 

 Remains I was not disposed to view them as relics of an extinct species ; for 

 although some presented characteristic diiferences from those of previously known 

 species, others were undistinguishable from the corresponding parts of the domestic 

 horse, and among them were intermediate varieties of form and size. The subse- 

 quent discovery of the remains of two species of the closely allied extinct gemis 

 Hipparion, in addition to the discovery of remains of two extinct equine genera of 

 an earlier geological period, leaves no room to doubt the former existence of the 

 horse on the American continent, contemporaneously with the Mastodon and 

 Megalonyx ; and man probably was his companion." 



The result of the whole seems to be, that of the animals found fossil in the post- 

 pliocene beds, all the mollusea of the present day are undoubtedly a perpetuation 

 of the same species ; that of the higher order of vertabrata, the tapir, peccary, 

 raccoon, opossum, deer, elk, and musk-rat are equally entitled to be considered the 

 descendants of this ancient race. And if the claims of the mollusea to this dis- 

 tinction rest upon a secure basis, because they are peculiar to this countiy, and not 

 obnoxious to suspicion of foreign immigration, it must be recollected that this is 

 (equally true of the above named animals. 



Those which have hitherto been regarded as of recent and European origin, are 

 the horse, sheep, hog and ox; and it must be reserved perhaps for future consider- 

 ation to determine how far the negative proof of the non existence of these animals 

 in the country at the time of its discovery may be regarded in each individual Case 

 sufficiently strong to settle the question of his extinction and re-introduction, 

 when so many of his associates and contemporaries have succeeded in maintaining 

 an unbroken line of descent down to the present day. 



The questions involved in the final results of these discoveries are as varied as 

 they are important. Professor Agassiz has taken up the inquiry with lively inter- 

 est, and in a letter to Professor Holmes observes :—" The circumstances under 

 which these remains are found, admit of no doubt, but the animals from which 

 they are derived, existed in North America long before this continent was settled 

 by the white race of men, together with animals which to this day are common in 

 the same localities, such as the deer, the musk-rat, the opossum, and others only 

 now found in South America, such as the tapir. This shows beyond the possibility 

 of controversy, that animals which cannot be distinguished from one another, 

 may originate independently in different fauna, and I take it that the facts you 

 have brought together are a satisfactory proof that horses, sheep, bulls and hogs, 

 not distinguishable at present from the domesticated species, were called into exist- 

 ence upon the continent of North America prior to the coming of the white race 

 to these parts, and that they had already disappeared here when the new comers 

 set foot upon this continent ; but the presence of tapir teeth among the rest show 

 also that a genus peculiar to South America and the Sunda Islands existed also in 

 North America iu those days, and that its representative of that period is not dis- 

 tinguishable from the South American species." 



