HUMAN AND OTHER SOCIETIES 127 



ing the less powerful, are sometimes satisfied 

 by their banishment ; the females may assist 

 after a battle has declared the victors. The 

 expelled males, without the protection of the 

 herd, probably quickly fall victims to preda- 

 tory animals. 



3. By the destruction of males by females : 

 this is not unknown. 



4. By enemies more frequently destroying 

 males than females because of their possessing 

 "attracting" characters. When a herd is 

 attacked the males, because they possess com- 

 bative and sacrificing instincts, usually protect 

 the young and the females, and must often 

 thus themselves be destroyed. 



If males and females were alike both in 

 characters and instincts, as many females 

 would be killed as males. 



By these methods, Natural Selection within 

 the herd is controlled. The adult male pos- 

 sesses special secondary sexual characters 

 for purposes of offence and defence ; the 

 young males are like the females and do not 

 present these characters, these offensive and 

 defensive instincts, until sexually mature 

 this because young males are more valuable 

 than old ones. 



The attracting colour of male birds, which 



