Chap. XI. BUTTERFLIES AND MOTHS. 41 



o 



female alone mocks a brilliantly-coloured and protected 

 species inhabiting the same district. Consequently the 

 female differs in colour from her own male, and, which 

 is a rare and anomalous circumstance, is the more 

 brightly-coloured of the two. In all the few species of 

 Pieridae, in which the female is more conspicuously 

 coloured than the male, she imitates, as I am informed 

 by Mr. Wallace, some protected species inhabiting the 

 same region. The female of Diadema anomala is rich 

 purple-brown with almost the whole surface glossed with 

 satiny blue, and she closely imitates the Eujoloea mida- 

 mus, "one of the commonest butterflies of the East;" 

 whilst the male is bronzy or olive-brown, with only a 

 slight blue gloss on the outer parts of the wings. 28 

 Both sexes of this Diadema and of D. bolina follow 

 the same habits of life, so that the differences in colour 

 between the sexes cannot be accounted for by exposure 

 to different conditions; 29 even if this explanation were 

 admissible in other instances. 30 



The above cases of female butterflies which are more 

 brightly-coloured than the males, shew us, firstly, that 

 variations have arisen in a state of nature in the female 

 sex, and have been transmitted exclusively, or almost ex- 

 clusively, to the same sex ; and, secondly, that this form 

 of inheritance has not been determined through natural 

 selection. For if we assume that the females, before 

 they became brightly coloured in imitation of some pro- 

 tected kind, were exposed during each season for a longer 

 period to danger than the males ; or if we assume that 



28 Wallace, "Notes on Eastern Butterflies," 'Transact. Ent. Soc.' 

 1869, p. 287. 



29 Wallace, in 'Westminster Eeview,' July, 1867, p. 37; and in 

 ' Journal of Travel and Nat. Hist.' vol. i. 1868, p. 88. 



30 See remarks by Messrs. Bates and Wallace, in ' Proc. Ent. Soc.' 

 Nov. 19, 1866, p. xxxix. 



