928 



GEOLOGY 



relics in America, but they should do so in time, if man lived 

 here in glacial or interglacial times. 



In Europe. The European data indicating great antiquity of 

 man are superior to the American. In Europe there are numerous 

 caves in which the relics of man, mingled with those of extinct 





Fig. 605. A gravel bluff formed by the under-cutting of the adjacent river. 



(After Holmes.) 



...---*"*****"" -..... -\.\* - " ' -Sv 



Fig. 606. The same at an early stage of talus formation. 





Fig. 607. The same at a late stage, when the slope has become nearly 



stable. 



animals, have been securely protected by layers of stalagmite. 

 While the ages of the stalagmite layers have rarely been fixed with 

 certainty, or well correlated with the glacial stages, they bear 

 inherent evidence of considerable antiquity. The European cave 

 evidence seems to have no strict counterpart in America. 



The association of man with extinct animals is a phenomenon 

 that may mean the extension of man's presence backward, or the 

 extension of the animals' presence forward ; and to this double- 

 faced problem research has not yet furnished a final key. ( )bviously. 



