GEOLOGY. 323 



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 dif- 

 ferences from those of previously known species, others were undistinguish- 

 able from the corresponding parts of the domestic horse, and among them 

 were intermediate varieties of form and size. The subsequent discovery of 

 the remains of two species of the closely allied extinct genus 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-pleiocene beds, all the mollusca of the present day are undoubtedly 

 a perpetuation of the same species ; that of the higher order of vertebrata, 

 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 mollusca to this distinction rest upon a secure basis, because 

 they are peculiar to this country, 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 ori- 

 gin, are the horse, sheep, hog, and ox; and it must be reserved perhaps for 

 future consideration 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. 



Prof. Agassiz's opinion in relation to these relics is expressed as follows : 

 There is hardly anything of interest in the bones themselves, since they all 

 belong to well-known types ; yet their simultaneous occurrence in the same 

 beds, showing that they lived together at a time when the white man had 

 not yet planted himself upon this continent, render their association undis- 

 puted. 



How does it happen that horses, sheep, bulls, and hogs, not distinguish- 

 able from our domestic species, existed upon this continent, together with 

 the deer, the inusk-rat, the beaver, the hare, the opossum, the tapir, which 

 in our days are peculiar to this continent, and not found in the countries 

 where our domesticated animals originated ? The whole matter might seem 

 to admit of any easy solution by supposing that the native American horse, 

 sheep, bull, and hog, were different species from those of the Old World, even 

 though the parts preserved show no specific differences ; but this would be 

 a mere theoretical solution of a difficulty which seems to me to have far 

 deeper meaning, and to bear directly upon the question of the first origin of 

 organized beings. 



The circumstances under which these remains are found, admit of no 

 doubt but the animals from which they are derived existed in North Amer- 

 ica 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 arid others only now found in South 

 America, such as the tapir. This shows, beyond the possibility of a contro- 

 versy, that animals which cannot be distinguished from one another, may 



