172 EVOLUTION 



As to preferential mating, there is no doubt 

 that the males, especially among birds, some- 

 times show off their varied attractions, but, 

 as Wallace has consistently maintained, there 

 is very little convincing evidence that the 

 female chooses a partner out of a number of 

 suitors. Still less is there evidence that she 

 chooses because of any particular excellence 

 in colour or in song or in dance. In some 

 cases, however, there is evidence that certain 

 males are left unmated, and that these are 

 inferior in attractiveness. In the mysterious 

 case of spiders, the fastidious female some- 

 times kills a suitor who does not adequately 

 please her; as well as afterwards, it may be, 

 the one who does. 



Since Darwin's day many of the supposed 

 cases of preferential mating have broken down 

 rather badly under criticism, but there are 

 still many facts to go upon. It seems clear 

 that the suitors are sometimes highly excited, 

 and that their displays often more reflex 

 than deliberate impetuously excite the fe- 

 male and overcome her coyness a character 

 which, as Groos points out, is of no incon- 

 siderable racial value. In some passages 

 Darwin seems to credit the female with a 

 high degree of " taste " or aesthetic fastidious- 

 ness; but he was probably on safer ground 



