The Descent of Man

y the females of their own species when carnivorous,
and no doubt by other species. Increased
size must be in some manner of more
importance to the females, than strength and
size are to the males for fighting with other
males; and this perhaps is to allow of the production
of a vast number of ova.
[Fig. 29. Callionymus lyra.
Upper figure, male;
lower figure, female.
N.B. The lower figure is more reduced than the
upper.]
In many species the male alone is ornamented
with bright colours; or these are much brighter
in the male than the female. The male, also, is
sometimes provided with appendages which
appear to be of no more use to him for the ordinary
purposes of life, than are the tail feathers
to the peacock. I am indebted for most of
the following facts to the kindness of Dr. Gunther.
There is reason to suspect that many tropi-