498 



GENERAL BIOLOGY 



Ontogeny. From birth onward the developmental 

 phases in man do not help greatly with the unravelling of 

 his history, for they are much altered by environmental 

 influences. But there are many things that are suggestive 

 of a sort of correspondence with phylogeny. The infant is 

 born with hands that are fitted for grasping, and capable of 

 sustaining^his weight. When he begins to travel he goes on 

 "all fours," and it is not until he assumes the erect position 



on his feet that he advances in action beyond his four-footed 

 relatives. Relieved of the function of support, his arms 

 learn throwing and striking and pulling. He imitates all 

 sorts of movements, and engages endlessly in play that is 

 imitative of the work of his elders, and that is essentially like 

 the play of other young mammals. At about the age of 

 twelve he appears to arrive at consciousness that he is a 

 part of a community; for he begins to play with his fellows 

 at cooperative games and organized sports; he enters upon 

 team work. 



