922 GEOLOGY 



on, the northern types were pressed well to the south, though not 

 so far as in the preceding epoch. In the third interglacial epoch t he 

 mammalian fauna included the Irish deer, the horse, the main- 

 moth, and the woolly rhinoceros. The climate seems to have been 

 congenial to a cool-temperate fauna. 



During the remaining epochs, the oscillations were apparently 

 less, and the to-and-fro migrations of life appear to have become 

 less and less, corresponding to the diminishing oscillations of the 

 glacial stages. 



. Pleistocene life of other continents. The Pleistocene life of 

 North America and Europe were similar, but that of South America 

 had a character quite its own. The major fauna was composed of 

 two great elements, (1) the gigantic sloths and armadillos, which 

 were indigenous to that country and very numerous, and (2) the 

 descendants of the Pliocene mammals which had migrated from 

 North America. Among the northern immigrants were horses, 

 mastodons, llamas, tapirs, wolves, and a large variety of rodents. 



Owing to the isolation of Australia, its organic development 

 followed lines of its own. The vertebrate fauna consisted exclu- 

 sively of marsupials and monotremes. In general, they differed, 

 specifically, from those now living, and were, on the whole, larger. 

 Although glaciers had but slight development in Australia, the 

 effects of the wide-spread refrigeration of the higher latitudes was 

 doubtless felt. 



Comparatively little is known of the Pleistocene life of Africa. 

 A moderate climate in the northern portion seems to be attested 

 by fluvial accumulations which have yielded remains of the buffalo. 

 antelope, hippopotamus, rhinoceros, and horse. These appear to 

 have belonged to an early stage of the Pleistocene. A later st 

 is represented by mollusks of existing species, and a mammalian 

 fauna embracing the elephant, buffalo, hippopotamus, antelope, 

 sheep, camel, and horse, a group differing widely from the present 

 occupants of the region. 



Man in the Glacial Period 



In America. Previous to the last decade of the last century. 

 no small mass of prehistoric material of human origin had been 



