186 NEW YORK ZOOLOGICAL SOCIETY. 



AFRICAN FAUNA. 



In this connection, the origin of the South African animals 

 may be briefly referred to. Madagascar has a peculiar fauna 

 resulting from long isolation, but the ancestral types came from 

 Africa, where, in later times, most of these particular animals 

 have died out. 



It had long been supposed that the lemurs, the pangolins, the 

 aardvarks, and some other types, were the only remnants of this 

 original fauna, and that the typical large mammals of Africa 

 originated in Eurasia, and were driven south into Africa by the 

 advance of the glaciers in comparatively recent times. Recent 

 investigations, however, have demonstrated the fallacy of this 

 view, and at present the best authorities concur in viewing Africa, 

 south of the Sahara, or the Ethiopian region, as having expe- 

 rienced a radiation of large mammals, quite peculiar to itself, 

 but which took place after the separation of Madagascar.* 



That the elephants originated in Africa has been demonstrated 

 by the recent discovery in Egypt of fossil forms, clearly ances- 

 tral to the modern Proboscidians. The Sirenia, the hyrax, the 

 hippopotamus, and related swine, the giraffe, and the wonderful 

 group of bovine antelopes in all probability attained their devel- 

 opment in Africa, and possibly all of the Bovidae originated 

 there also. In Pliocene and Lower Pleistocene times many of 

 these forms pushed north, in some cases as far as England, there 

 becoming extinct or retreating into Africa again upon the ad- 

 vance of the glaciers, but leaving behind in Europe and Asia 

 some of their members, which successfully adjusted themselves 

 to temperate or subarctic conditions. 



PREGLACIAL FAUNA OF AMERICA. 



During these same periods before the approach of the glaciers 

 a magnificent fauna flourished in North America, consisting of 

 camels, horses, ground sloths, elephants, mastodons, sabre- 

 toothed tigers, and others, including distinct forest and plains 

 faunae, but few of these animals seem to have survived the great 

 glaciers. One of the survivors was the mastodon, which, origi- 



*This hypothesis was first fully set forth by Prof. Henry Fairfield Osborn, 

 before the New York Academy of Science in 1900, and has been more than con- 

 firmed by the explorations of the Egyptian Geological Survey, published by 

 Andrews & Beadnell. 



