39(i HEREDITY AND ENVIRONMENT 



taking place in the radium atom we can only 

 look on while the evolutionary processes pro- 

 ceed, selecting here and there a product which 

 nature gives us but unable to initiate or con- 

 trol these processes. 



B. CONTROL OF HUMAN HEREDITY: 

 EUGENICS 



I. PAST EVOLUTION OF MAN 



There is every evidence that man also, no 

 less than domesticated animals, has evolved 

 from a natural or wild state. The most primi- 

 tive types of men are known only from a few 

 fossil remains, which indicate that these primi- 

 tive men belonged to different species, and 

 some of them even to different genera, from 

 Homo sapiens (Fig. 96). Later stages in the 

 evolution of man are known from many re- 

 mains, implements and handiwork, as well as 

 from certain primitive races or tribes which 

 have persisted to the present time. The grades 

 of culture represented by these extinct or per- 

 sistent tribes and by modern men are usually 

 classified as savagery, barbarism and civiliza- 



