PRESENT AND PAST. 173 



when any country possesses a peculiar fauna, the 

 fossils indicate that the same peculiarity existed in 

 times past, although it usually happens that no 

 species found to-day exists as a fossil. That this 

 fact is an indication of genetic connection between 

 the present and the past, is evident enough. 



When, however, we examine the great bulk of 

 species on our larger continents, we soon discover 

 that the present distribution of many of them is by 

 no means similar to that of their fossil representa- 

 tives. Many animals now confined to small locali- 

 ties formerly ranged widely. Species, genera, and 

 families which have in the past wandered to and 

 fro with varying conditions, have become extinct 

 to such an extent as to obscure the general relation 

 just noticed. Horses, for instance, were not found 

 in America when discovered, although fossils tell us 

 that they did exist here in the very recent geological 

 times. Fossil camels appear in our rocks, although 

 no living camel belongs to the New World. Ameri- 

 ca formerly had a fauna composed of elephants, hip- 

 popotamuses, tapirs, and hosts of other animals now 

 found in Africa or India. All this is, however, not 

 surprising, for migration and extinction have been 

 abundant. If it had appeared that America when 

 discovered possessed a large family of horses, while 

 its fossils showed no trace of them it would haye 

 presented serious trouble ; but no case of this kind 

 is forthcoming. 



In this connection has appeared one result of 

 special interest. The study of the fossils of North 

 America and Europe discloses the fact that only a 



