n of
sexual colours from total dissimilarity to perfect identity. If this is
explained solely by the laws of inheritance, then the colours of one or
other sex will be always (in relation to their environment) a _matter of
chance_. I cannot think this. I think Selection more powerful than laws
of inheritance, of which it makes use, as shown by cases of two, three
or four forms of female butterflies, all of which have, I have little
doubt, been specialised for protection.

To answer your first question is most difficult, if not impossible,
because we have no sufficient evidence in _individual cases of slight
sexual difference_, to determine whether the male alone has acquired his
superior brightness by sexual selection, or the female been made duller
by need of protection, or whether the two causes have acted. Many of the
sexual differences of existing species may be inherited differences from
parent forms who existed under different conditions and had greater or
less need of protection.

I think I admitted before the general tendency (probably) of males to
acquire brighter tints. Yet this cannot be universal, for many female
birds and quadrupeds have equally bright tints.

I think the case of [female symbol] _Pieris pyrrha_ proves that females
alone can be greatly modified for protection.

To your second question I can reply more decidedly. I do think the
females of the Gallmaceae you mention have been modified or been
prevented from acquiring the brighter plumage of the male by need of
protection. I know that the _Gallus bankiva_ frequents drier and more
open situations than the pea-hen of Java, which is found among grassy
and leafy vegetation corresponding with the colours of the two. So the
Argus pheasant, [male symbol] and [female symbol], are, I feel sure,
protected by their tints corresponding to the dead leaves of the lofty
forest in which they dwell, and the female of the gorgeous fire-back
pheasant, _Lophura viellottii_, is of a very similar _rich brown
colour_. I do not, however, at all think the question can be settled by
individual cases, but only by large masses of facts.

The colours of the mass of female birds seem to me strictly analogous to
the colours of both sexes of snipes, woodcocks, plovers, etc., which are
undoubtedly protective.

Now, supposing, on your view, that the colours of a male bird become
more and more brilliant by sexual selection, and a good deal of that
colour is transmitted to