354 THE DESCENT OF MAN. 



peacock Vanessse, our white cabbage-butterflies (Pieris), or 

 the great swallow-tail Papilio which haunts the open fens 

 for these butterflies are thus rendered visible to every living 

 creature. In these species both sexes are alike; but in the 

 common brimstone butterfly ( Gonepteryx rhamni), the male 

 is of an intense yellow, while the female is much paler; and 

 in the orange-tip (Anthocharis cardamines) the males alone 

 have their wings tipped with bright orange. Both the 

 males and females in these cases are conspicuous, and it is 

 not credible that their difference in color should stand in 

 any relation to ordinary protection. Prof. Weismann 

 remarks * that the female of one of the Lycaense expands 

 her brown wings when she settles on the ground, and is 

 then almost invisible; the male, on the other hand, as if 

 aware of the danger incurred from the bright blue of the 

 upper surface of his wings, rests with them closed; and this 

 shows that the blue color cannot be in any way protective. 

 Nevertheless, it is probable that conspicuous colors are 

 indirectly beneficial to many species, as a warning that they 

 are unpalatable. For in certain other cases, beauty has 

 been gained through the imitation of other beautiful 

 species, which inhabit the same district and enjoy an im- 

 munity from attack by being in some way offensive to their 

 enemies; but then we have to account for the beauty of the 

 imitated species. 



As Mr. Walsh has remarked to me, the females of our 

 orange-tip butterfly, above referred to, and of an American 

 species (Anth. genutia) probably show us the primordial 

 colors of the parent-species of the genus; for both sexes of 

 four or five widely-distributed species are colored in nearly 

 the same manner. As in several previous cases, we may 

 here infer that it is the males of Anth. cardamines and 

 genutia which have departed from the usual type of the 

 genus. In the Anth. sara from California, the orange tips 

 to the wings have been partially developed in the female ; 

 but they are paler than in the male, and slightly different 

 in some other respects. In an allied Indian form, the 

 Iphias glaucippe, the orange-tips are fully developed in 

 both sexes. In this Iphias, as pointed out to me by Mr. A. 

 Butler, the under surface of the wings marvelously resem- 

 bles a pale-colored leaf; and in our English orange-tip, the 



* - Binfluss der Isolirung auf di. Artbildung," 1872, p. 53. 



