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TRANS. ST. LOUIS ACAD. SCIENCE. 



and in Buenos Ayres, together with the bones of extinct animals 

 of Postpliocene age. 



There would seem to be good reasons for believing that the 

 Rhinoceros, Camel, and Horse, had their first evolution into these 

 types in western North America, and that they passed into the 

 Palaearctic province in Tertiary times. The recent discoveries of 

 fossil remains in the western Territories of the United States, in 

 the hands of our palaeontologists, furnish a more complete history 

 of the evolution of these types than is found in any other part of 

 the globe. Both Rhinoceroses and Elephants are found in the 

 Tertiary of Europe, Africa, and southeastern Asia, and they may 

 have passed either from or to America by this same route. Fossil 

 horses have been found in South America, and they have been 

 reported from the Postpliocene deposits of the United States ; but 

 no rhinoceros, or camel, has been found to the eastward of that 

 ancient Pliocene lake, in that or in any older period. Lemuroids 

 are reported from the Eocene of these western Territories, and 

 also forms having affinities with the apes. It would, therefore, 

 appear to be certain, either that Lemurs and Apes had a distinct 

 evolution in the Nearctic province also, or that in the Eocene 

 these types extended from Europe to America. The Lemurs are 

 extinct on this continent, but the Apes survive in Central and 

 South America in tropical forests suitable to their mode of life. 

 Remains of Apes, kindred in form to those now living in South 

 America, have been found in Brazil together with those of extinct 

 Postpliocene animals. It is pretty certain that they passed into 

 South America from the north after the Miocene ocean barrier 

 across the isthmus had disappeared. They differ so much from 

 the old-world Apes as to demonstrate a. very remote branching 

 from the same stem, even if they did not originate independently 

 on this continent. No anthropoid forms have ever been found 

 among them on this continent, fossil or living. Zoologically, the 

 human type has much nearer affinities with the Catarhine Apes 

 of Asia and Africa than with the American forms. It is, indeed, 

 just as possible that the American Lemuroids and Apes had an 

 independent evolution from lower types of animals on this conti- 

 nent as that the same thing should take place in the Palcearctic 

 province. But the first existence of Man in America is suffi- 

 ciently accounted for by the supposed derivation from Asia. 



