Chap. XI.] BUTTERFLIES AND MOTHS. 395 



the females had their bright colors increased; and this 

 would tend throughout the Order to diminish the number 

 of species with brightly-colored females in comparison 

 with the species having brightly-colored males. On the 

 other hand, as bright colors are supposed to be highly ser- 

 viceable to the males in their love-struggles, the brighter 

 males (as we shall see in the chapter on Birds) although 

 exposed to rather greater danger, would on an average 

 procreate a greater number of offspring than the duller 

 males. In this case, if the variations were limited in their 

 transmission to the male sex, the males alone would be 

 rendered more brilliantly colored; but if the variations 

 were not thus limited, the preservation and augmentation 

 of such variations would depend on whether more evil 

 was caused to the species by the females being rendered 

 conspicuous, than good to the males by certain individuals 

 being successful over their rivals. 



As there can hardly be a doubt that both sexes of 

 many butterflies and moths have been rendered dull-col- 

 ored for the sake of protection, so it may have been with 

 the females alone of some species in which successive 

 variations toward dulness first appeared in the female sex, 

 and were from the first limited in their transmission to 

 the same sex. If not thus limited, both sexes would be- 

 come dull-colored. We shall immediately see, when we 

 treat of mimicry, that the females alone of certain but- 

 terflies have been rendered extremely beautiful for the 

 sake of protection, without any of the successive protec- 

 tive variations having been transferred to the male, to 

 whom they could not possibly have been in the least de- 

 gree injurious, and therefore could not have been elimi- 

 nated through natural selection. Whether in each par- 

 ticular species, in which the sexes differ in color, it is the 

 female Avhich has been specially modified for the sake of 

 protection; or whether it is the male which has been spe- 



