THE VOYAGE OF EVOLUTION 121 



The approach of this severe climate was gradual. First there 

 was a long period of relatively cool, dry conditions. Central 

 France, for example, may have been something like what south- 

 eastern Russia now is. This caused the disappearance of two 

 rather sensitive Asiatic mammals, the hippopotamus and the 

 southern mammoth. Then, as the Scandinavian ice-sheet accumu- 

 lated farther north, the climate became more severe. Men repaired 

 to the shelter of grottos and caverns as they had not for tens of 

 thousands of years. The hardy broad-nosed rhinoceros and 

 straight-tusked elephant both disappeared, while animals of the 

 cold Arctic tundra, such as the reindeer, the woolly mammoth, the 

 woolly rhinoceros, and the Arctic lemming, migrated all over 

 southern Britain, Belgium, France, Germany, and Austria. This 

 condition was too severe for early man. The stage of human 

 development, which coincides with the beginning of refrigeration, 

 "is seen to present the climax of a gradual and unbroken develop- 

 ment" not only in industries but in ideas. The next industrial 

 stage, which certainly presents the closing workmanship of the 

 same Neanderthal race, and which coincides with the main cold 

 period of the Fourth Glaciation, "shows a marked retrogression 

 of technique in contrast to the steady progression which we have 

 observed up to this time." (Osborn, page 180.) 



The climatic conditions which were unfavorable to development 

 in central Europe seem to have been highly favorable in other 

 places where they were not quite so severe. Thus somewhere in 

 central Asia there appears to have developed during this period 

 the great Cro-Magnon race. These highly gifted people had 

 brains as large as those of modern Europeans. They invaded 

 southern Europe after the most severe part of the Fourth Glacial 

 Epoch had passed away. "After prolonged study of the works 

 of the Cro-Magnons one cannot avoid the conclusions that their 

 capacity was nearly if not quite as high as our own; that they 

 were capable of advanced education; that they had a strongly 

 developed aesthetic as well as a religious sense; that their society 



