Chap., XI. Butterflies and Moths. 3 19 



In England we have some analogous cases, though not so 

 marked. The females alone of two species of Thecla have a 

 bright-purple or orange patch on their fore-wings. In Hip- 

 parchia the sexes do not differ much ; but it is the female of 

 H. janira which has a conspicuous light-brown patch on her 

 wings ; and the females of some of the other species are brighter 

 coloured than their males. Again, the females of Col ins edusa 

 and hyah have " orange or yellow spots on the black marginal 

 w border, represented in the males only by thin streaks ; " and 

 in Pieris it is the females which " are ornamented with black 

 " spots on the fore-wings, and these are only partially present 

 " in the males." Now the males of many butterflies are known 

 to support the females during their marriage flight ; but in the 

 species just named it is the females which support the males ; 

 so that the part which the two sexes play is reversed, as is their 

 relative beauty. Throughout the animal kingdom the males 

 commonly take the more active share in wooing, and their 

 beauty seems to have been increased by the females having 

 accepted the more attractive individuals ; but with these but- 

 terflies, the females take the more active part in the final mar- 

 riage ceremony, so that we may suppose that they likewise do 

 so in the wooing; and in this case we can understand how it is 

 that they have been rendered the more beautiful. Mr. Meldola, 

 from whom the foregoing statements have been taken, says in 

 conclusion ; " Though I am not convinced of the action of 

 " sexual selection in producing the colours of insects, it cannot 

 " be denied that these facts are strikingly corroborative of 

 " Mr. Darwin's views." 23 



As sexual selection primarily depends on variability, a few 

 words must be added on this subject. In respect to colour 

 there is no difficulty, for any number of highly variable Lepi- 

 doptera could be named. One good instance will suffice. Mr. 

 Bates shewed me a whole series of specimens of Papilio sesostris 

 and P. childrence ; in the latter the males varied much in the 

 extent of the beautifully enamelled green patch on the fore- 

 wings, and in the size of the white mark, and of the splendid 

 crimson stripe on the hind-wings ; so that there was a great 

 contrast amongst the males between the most and the least 

 gaudy. The male of Papilio sesostris is much less beautiful 

 than of P. childrence ; and it likewise varies a little in the size of 



23 'Nature,' April 27th, 1871, p. whilst pairing. See also Mr. G. 



508. Mr. Meldola quotes Donzel, Fraser, in 'Nature,' April 20th, 



in ' Soc. Ent. de France,' 1837, p. 1871, p. 489, on the sexual differ- 



77, on the flight of butterflies euces of several British butterflies. 



