The Theory of Sexual Selection. G01) 
We may next proceed to consider the objections 
which have been brought against the theory of sexual 
selection. And this is virtually the same thing as 
saying that we may now consider Mr. Wallace’s views 
upon the subject. 
Reserving for subsequent consideration the most 
general of these objections—namely, that at best the 
theory can only apply to the more intelligent animals, 
and so must necessarily fail to explain the phenomena 
of beauty in the less intelligent, or in the non- 
intelligent, as well as in all species of plants—we may 
take seriatim the other objections which, in the opinion 
of Mr. Wallace, are sufficient to dispose of the theory 
even as regards the higher animals. 
In the first place, he argues that the principal 
cause of the greater brilliancy of male animals in 
general, and of male birds in particular, is that they 
do not so much stand in need of protection arising 
from concealment as is the case with their respective 
females. Consequently natural selection is not so 
active in repressing brilliancy of colour in the males, 
“or, which amounts to the same thing, is more active 
in “repressing in the female those bright colours 
which are normally produced in both sexes by general 
laws.” 
Next, he argues that not only does natural selection 
thus exercise a negative influence in passively per- 
mitting more heightened colour to appear in the 
males, but even exercises a positive influence in 
actively promoting its development in the males, 
while, at the same time, actively repressing its ap- 
pearance in the females. For heightened colour, he 
says, is correlated with health and vigour ; and as there 
