SEPARATION OF SEXES 99 



tors had scattered. When these latter had learned 

 the use of clubs and missiles, however, they devoted 

 themselves to the destruction of life with such won- 

 derful ability and passionate energy and persever- 

 ance, that the contrast between the redundancy of 

 mammalian life before that period and its scarcity 

 afterward must have been enormous. 



The conclusion then is safely established, that 

 when our brute ancestors first learned the use of 

 clubs and missiles they lived in a habitat densely 

 crowded with mammalian life, among which the 

 larger carnivora must have been a numerous class, 

 because the creatures on which they habitually feed 

 were so very plentiful. 



A crowded habitat necessarily implies severe and 

 close competition for the primary necessaries of exist- 

 ence, such as food, drink, shelter, opportunity to 

 reproduce, etc., etc. Severe and close competition 

 is the condition which makes the second part of the 

 struggle for existence most intense. When the strug- 

 gle for existence is the in tensest, natural selection 

 is most exacting. Only the most competent among 

 the races and varieties survive, and within these, 

 again, only the most competent individuals. Such 

 conditions could only react favorably upon the 

 average excellence and numerical strength of the 

 higher mammalia, which are so well provided with 

 means of offence, defence, protection, escape, and 

 multiplication. But our brute ancestors, while 

 selected most exactingly with reference to strength, 



