The Descent of Man

eing eliminated when transferred to the male
and in any way injurious to him. Thus the plumage
of the female would be kept constant in
character. It would also be a relief if we could
admit that the obscure tints of both sexes of
many birds had been acquired and preserved
for the sake of protection,—for example, of the
hedge-warbler or kitty-wren (Accentor modularis
and Troglodytes vulgaris), with respect to
which we have no sufficient evidence of the
action of sexual selection. We ought, however,
to be cautious in concluding that colours which
appear to us dull, are not attractive to the females
of certain species; we should bear in mind
such cases as that of the common housesparrow,
in which the male differs much from
the female, but does not exhibit any bright tints.
No one probably will dispute that many gallinaceous
birds which live on the open ground,
have acquired their present colours, at least in
part, for the sake of protection. We know how
well they are thus concealed; we know that