OUR FACE FROM FISH TO MAN 



extent in basic mental traits (Yerkes, Koehler) all 

 sufficiently establish the fact that at one time the 

 human and anthropoid groups converged back- 

 ward to a common source. It is also the plain 

 teaching of comparative anatomy that the modern- 

 ized white human face with its small mouth, weak 

 jaws, reduced dentition, projecting chin, delicate 

 projecting nose and pale skin, has changed far 

 more from the primitive man-anthropoid starting- 

 point than has the face of a young chimpanzee, 

 with huge mouth, strong teeth, receding chin and 

 flat nose. Professor Osborn holds that the separa- 

 tion of man and apes from the primitive anthro- 

 poid stock began as far back as the Lower Oligo- 

 cene epoch, possibly some thirty -five million years 

 ago, while the present writer is inclined to date 

 this event from the next higher epoch, namely 

 the Lower Miocene, possibly nineteen million 

 years ago. * 



Whichever date, if either, may eventually prove 

 to be the true one, the fact remains that in its 

 present form the modernized human face is sui 



' These figures are according to the tentative estimates of the geo- 

 logical epochs worked out by Barrell by the "radium emanation" 

 method, based on the rate of disintegration of radioactive ores from 

 different geological horizons. 



74 



