Chap. XL] BUTTERFLIES AND MOTHS. 393 



inconspicuous, from having more need of protection than 

 the males. This supposed difference in the " need of pro- 

 tection by the two sexes " is rather deceptive, and requires 

 some discussion. It is obvious that bi'ightly-colored indi- 

 viduals, whether males or females, would equally attract, 

 and obscurely-colored individuals equally escape, the at- 

 tention of their enemies. But we are concerned with the 

 effects of the destruction or preservation of certain indi- 

 viduals, of either sex, on the character of the race. With 

 insects, after the male has fertilized the female, and after 

 the latter has laid her eggs, the greater or less immunity 

 from danger of either sex could not possibly have any 

 elFect on the offspring. Before the sexes have performed 

 their proper functions, if they existed in equal numbers 

 and if they strictly paired (all other circumstances being 

 the same), the preservation of the males and females 

 would be equally impoi'tant for the existence of the spe- 

 cies and for the character of the offspring. But with 

 most animals, as is known to be the case with the do- 

 mestic silk-moth, the male can fertilize two or three 

 females ; so that the destruction of the males would not 

 be so injurious to the species as that of the females. On 

 the other hand. Dr. Wallace believes that with moths the 

 progeny from a second or tliird fertilization is apt to 

 be weakly, and therefore would not have so good chance 

 of surviving. When the males exist in much greater 

 numbers than the females, no doubt many males might 

 be destroyed with impunity to the species ; but I cannot 

 see that the results of ordinary selection for the sake of 

 protection would be influenced by the sexes existing in 

 unequal numbers ; for the same pi'oportion of the more 

 conspicuous individuals, whether males or females, would 

 probably be destroyed. If, indeed, the males presented a 

 greater range of variation in color, the result would be 

 different ; but we need not here follow out such complex 



