718 -The Colors of Animals and Plants. — [ December, 
among these there is literally not one particle of evidence that 
the female is influenced by color, or even that she has any power 
of choice, while there is much direct evidence to the contrary 
(Descent of Man, page 318). The weakness of the evidence 
for sexual selection among these insects is so palpable that Mr. 
Darwin is obliged to supplement it by the singularly inconclu- 
sive argument that ‘unless the females prefer one male to an- 
other, the pairing must be left to mere chance, and this does not 
appear probable” (loc. cit., page 317). But he has just said, 
“ The males sometimes fight together in rivalry, and many may 
be seen pursuing or crowding round the same female ;” while in 
the case of the silk-moths, “ the females appear not to evince the 
least choice in regard to their partners.” Surely, the plain in- 
ference from all this is, that males fight and struggle for the 
almost passive female, and that the most vigorous and energetic, 
the strongest-winged or the most persevering, wins her. How 
can there be chance in this? Natural selection would here act, as 
in birds, in perpetuating the strongest and most vigorous males, 
and as these would usually be the more highly-colored of their 
race, the same results would be produced as regards the intensifi- 
cation and variation of color in the one case as in the other. 
Let us now see how these principles will apply to some of the 
eases adduced by Mr. Darwin in support of his theory of volun- 
tary sexual selection. 
~ In Descent of Man, second edition, pp. 307-816, we find an 
elaborate account of the various modes of coloring of butterflies 
and moths, proving that the colored parts are always more or 
less displayed, and that they have some evident relation to an 
observer. Mr. Darwin then says: “ From the several foregoing 
facts it is impossible to admit that the brilliant colors of butter- 
flies, and of some few moths, have commonly been acquired for 
the sake of protection. We have seen that their colors and 
elegant patterns are arranged and exhibited as if for display. 
Hence, I am led to believe that the females prefer or are most 
excited by the more brilliant males ; for on any other supposition 
the males would, as far as we can see, be ornamented to no pur 
pose ” (loe. cit., p. 316). Iam not aware that any one has ever 
maintained that the brilliant colors of butterflies have “ com- 
monly been acquired for the sake of protection,” yet Mr. Darwin 
has himself referred to cases in which the brilliant color 18 50 
placed.as to serve for protection; as, for example, the eye 
on the hind-wings of moths, which are pierced by birds, and a 
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