SEXUAL COLOUR 89 



when the members of a species are not all 

 of equal value, the less valuable will be more 

 likely to be destroyed than the more valuable. 



It is as if the species, realising that it must 

 form the food supply of another species and 

 that certain of its members must be destroyed, 

 conserved its valuable members, by casting 

 its valueless ones to satisfy the enemy. 



This it does, not actively but passively, by 

 so clothing the valueless that they will be 

 more easily seen by the enemy and thus more 

 liable to be attacked. 



As before mentioned, it does not follow that 

 in every case they will be destroyed, they may 

 make good their escape ; but by drawing the 

 attack, the valuable will be preserved from 

 attack. 



Further, it is obvious that there will be a 

 limit to this value marking : as, for instance, 

 when males become less numerous than 

 females, so their relative value will increase ; 

 they are not entirely valueless. 



When they thus become of equal value as 

 the female, further alteration in structure will 

 cease. 



The limit to which this differentiation will 

 proceed, will depend on the number of females 

 a single male is able to fertilise, or his initial 



