Energy in Animals 39 



It develops after the boy has reached sexual 

 maturity, and a consideration of the manner 

 in which it is transmitted through successive 

 generations will illustrate the transmission of 

 secondary sexual characters in general. The 

 father has a beard, and though the daughter 

 inherits other characteristics from her father, 

 she does not inherit his beard. Yet that 

 daughter's son may have a beard like that of 

 his maternal grandsire. In this case, the son 

 inherits a peculiar form of beard from his 

 mother, who had no beard at all. Hence, 

 though we speak of a secondary sexual 

 character peculiar to the male as being absent 

 in the female, it is suppressed rather than 

 absent in essence. Similarly a bull trans- 

 mits to his daughters the milking qualities of 

 his dam, though he had no milking qualities 

 of his own. 



There is nothing in the science of physics 

 which would classify energy accumulated dur- 

 ing the adult stage as being a secondary 

 sexual character, but the biological fact that 

 numerous animal functions are secondary 



