374 



HISTORICAL GEOLOGY 



most recent knowledge based upon the work of able students 



of the subject. 



The introduc- 

 tion of the so- 

 called "Eolithic" 

 period into this 

 table seems doubt- 

 fully appropriate 

 in the light of our 

 best knowledge, 

 though it is possi- 

 ble that certain 

 very rude stone 

 implements such 

 as those found by 

 Prestwich in the 

 high river gravels 

 in Kent (Eng- 

 land) belong 

 to such an early 

 period. 



Fig. 231 

 Table to show the principal geologic stages in the 

 history of Man. (After C. Wissler, courtesy of the 

 American Museum of Natural History.) 







Historic (bronze and iron) age. 



Modern. 



3. 



Homo sapiens 



Neolithic ("recent stone") age. 



Post-Glacial 





(e.g. modern Men). 



(Carefully shaped and polished 



but pre- 







stone implements.) 



Historic. 







Upper Paleolithic ("ancient stone") 





2. 



Homo primigenius 



age. (Rough bone and stone im- 



Late Pleisto- 





(Primitive Men, e.g. 



plements, cave frescoes, bone car- 



cene. 





Men of Neanderthal, 



vings, etc.) 







La Chapelle, Spy, 



Lower Paleolithic ("ancient stone") 



Middle Pleis- 





Krapina, etc.). 



age. (Rude stone implements of 

 so-called "River Man.") 



tocene. 



1. 



Early ancestral forms 









(Apes, or Man-like 





Early Pleisto- 





Apes, e.g. Pithecan- 

 thropus erectus and 



(No known implements.) 



cene 

 or 





Homo heidelbergen- 





Pliocene. 





sis) . 







