Chap. XI. 
BUTTERFLIES AND MOTHS. 
405 
one form of inheritance into the other. But 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 Heliconidde , Danaidse, Acroeidse 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. R. Wallace, in 1 The Journal of Travel,’ vol. i. 1868, p. 88. 
4 Westminster Review,’ July, 1867, p. 37. See also Messrs. Wallace 
•and Bates in 4 Proc. Ent. Soc.’ Nov. 19th, 1866, p. xxxix. 
