The Descent of Man

lation, we can hardly avoid the conclusion that
they have been acquired through sexual selection
for the sake of ornament, and have been
transmitted exclusively, or almost exclusively,
to the same sex. When both sexes are coloured
in the same manner, and the colours are conspicuous
or curiously arranged, without being
of the least apparent use as a protection, and
especially when they are associated with various
other ornamental appendages, we are led
by analogy to the same conclusion, namely,
that they have been acquired through sexual
selection, although transmitted to both sexes.
That conspicuous and diversified colours,
whether confined to the males or common to
both sexes, are as a general rule associated in
the same groups and sub-groups with other
secondary sexual characters serving for war or
for ornament, will be found to hold good, if we
look back to the various cases given in this and
the last chapter.