COLOURS PRODUCED BY COURTSHIP 309 



it renders it entirely ineffective.' This opinion can 

 hardly be maintained if we believe that such pre- 

 ference leads to the failure, comparative or complete, 

 of the plainer or less graceful males, although the equal 

 in other respects of their more successful rivals. 

 Each of these two processes will check the other : 

 Natural Selection will ensure that the males which 

 succeed because of their beauty are among the fittest ; 

 Sexual Selection will ensure that the males which suc- 

 ceed on account of their * fitness ' are among the 

 most beautiful. 



When courtship is decided by wager of battle. Sexual 

 Selection is hardly called into play 



When the males habitually fight for the possession 

 of the females, and successful courtship is determined 

 by victory, the results are, as Mr. Wallace points out, 

 due to Natural Selection rather than Sexual Selection. 

 It is, I think, in favour of Mr. Darwin's theory, that any 

 remarkable beauty of colour or pattern is generally 

 absent when the possession of the female is determined 

 by wager of battle ; while the special weapons of such 

 warfare are generally wanting when any peculiar beauty 

 exists : there are, however, exceptions to this rule. Mr. 

 Wallace points out that * almost all male animals fight 

 together, though not specially armed,' but there is no 

 evidence to show that courtship is frequently decided 

 in this way. 



