MAMMALS. 



631 



size, strength, courage arid pugnacity of the male, his 

 special weapons of offense, as well as his special means of 

 defense, have been acquired or modified through that form 

 of selection which I have called sexual. This does not 

 depend on any superiority in the general struggle for life, 



Fig. 78. Cercopithecus diana (from Erehm). 



but on certain individuals of one sex, generally the male, 

 being successful in conquering other males, and leaving a 

 larger number of offspring to inherit their superiority than 

 do the less successful males. 

 There is another and more peaceful kind of contest, in 



