Chap. XI. BUTTERFLIES AND MOTHS. 405 



one form of inheritance into the other. Bat by the 

 selection of successive variations, which were from the 

 first sexually limited in their transmission, there would 

 not be the slightest difficulty in giving bright colours to 

 the males alone, and at the same time or subsequently, 

 dull colours to the females alone. In this latter manner 

 female butterflies and moths may, as I fully admit, have 

 been rendered inconspicuous for the sake of protection, 

 and widely different from their males. 



Mr. Wallace 22 has argued with much force in favour 

 of his view that when the sexes differ, the female has 

 been specially modified for the sake of protection ; and 

 that this has been effected by one form of inheritance, 

 namely, the transmission of characters to both sexes, 

 having been changed through the agency of natural 

 selection into the other form, namely, transmission to 

 one sex. I was at first strongly inclined to accept this 

 view ; but the more I have studied the various classes 

 throughout the animal kingdom, the less probable it 

 has appeared. Mr. Wallace urges that both sexes of 

 the Heliconidae, Danaidse, Acrseidm are equally brilliant 

 because both are protected from the attacks of birds 

 and other enemies, by their offensive odour ; but that 

 in other groups, which do not possess this immunity, 

 the females have been rendered inconspicuous, from 

 having more need of protection than the males. This 

 supposed difference in the " need of protection by the 

 " two sexes ' is rather deceptive, and requires some 

 discussion. It is obvious that brightly-coloured indi- 

 viduals, whether males or females, would equally attract, 

 and obscurely-coloured individuals equally escape, the 



22 A. E. Wallace, in 'The Journal of Travel,' vol. i. 1868, p. 88. 

 'Westminster Keview,' July, 1867, p. 37. See also Messrs. Wallace 

 and Bates in ' Proc. Ent. Soc' Nov. 19th, 1S66, p. xxxix. 



