

Organic Evolution. 199 



probably in the large, branching antennae. There can 

 be little doubt that, if an individual is deficient in this 

 sense, or misinterprets the direction in which the virgin 

 female lies, he will be unsuccessful in the competition for 

 mates ; he will be eliminated from procreation. And it is 

 a familiar observation of the poultry-yard that the law of 

 battle soon determines which among the cock birds shall 

 procreate their kind. The law of battle for mates is, in- 

 deed, an established fact among many animals, especially 

 those which are polygamous, and the elimination of the 

 unfit in this respect is a logical necessity. 



It is when we come to the second of the two' modes, 

 that which involves selection proper, that we find differences 

 of opinion among naturalists. 



Darwin, as we have seen, suggested that those secondary 

 sexual characters which can be of no value in aiding their 

 possessor to escape elimination by combat result from the 

 preferential choice of the female, the female herself remain- 

 ing comparatively unaffected. But Mr. Wallace made an 

 exceedingly valuable suggestion with regard to these com- 

 paratively dull colours of the female. He pointed out that 

 conspicuousness (unless, as we have seen, accompanied by 

 some protective character, such as a sting or a bitter taste) 

 increased the risk of elimination by enemies. Now, the 

 males, since they are generally the stronger, more active, 

 and more pugnacious, could better afford to run this risk 

 than their mates. They could to some extent take care 

 of themselves. Moreover, when impregnation was once 

 effected, the male's business in procreation was over. Not 

 so the female ; she had to bear the young or to lay the 

 eggs, often to foster or nourish her offspring. Not only 

 were her risks greater, but they extended over a far longer 

 period of time. Hence, according to Mr. Wallace, the dull 

 tints of the females, as compared with those of the males, 

 are due to natural selection eliminating the conspicuous 

 females in far greater proportion than the gaudy males. 



,- There is clearly no reason why this view should not be 

 combined with Darwin's ; preferential mating being one 



