120 WORLD-POWER AND EVOLUTION 



lived through three great glacial epochs, but he had never been 

 subjected to a really severe climate. Now for the first time he 

 endured one, for the last epoch was much more rigorous than its 

 predecessors. At the same time his evolution proceeded much 

 more rapidly than ever before. Let us try to get at the meaning 

 of these facts. In the first place are we sure of them? The proof 

 lies in the animals whose fossil bones are found in large numbers 

 in connection with the remains of early man. In this respect, as 

 in most questions concerning primitive man, we must rely on evi- 

 dence from central and western Europe, for only there has any 

 abundant evidence of our remote ancestors yet come to light. 

 "Until the close of Third Interglacial times," says Osborn, that 

 is, until the approach of the last glacial epoch, "no traces of 

 northern, much less of arctic forests and animals are discovered 

 anywhere, except along the borders of the ice-fields. It would 

 appear as if the animal and plant life of Europe were, in the main, 

 but slightly affected by the first three glaciations. We cannot 

 entertain for a moment the belief that in glacial times all the 

 warm flora and fauna migrated southward and then returned, 

 because there is not a shred of evidence for this theory. It is far 

 more in accord with the known facts to believe that all the 

 southern and eastern forms of life had become very hardy, for 

 we know how readily animals now living in the warm earth belts 

 are acclimatized to northern conditions" (page 108). The tiger, 

 for example, thrives today in Manchuria, where temperatures of 

 20°F below zero are not uncommon. 



The meaning of this seems to be that during the earlier glacial 

 epochs such regions as southern France, for example, became 

 colder and stormier than now, but not cold enough to exterminate 

 such animals as the horse and rhinoceros. During the last Glacial 

 Epoch, however, although the ice-covered areas in western Europe 

 and Britain were far more limited than during the Third Glacial 

 Epoch, "the climate appears to have been more severe than at any 

 previous period." (Osborn.) 



