The Descent of Man

ser cygnoides), which is much larger in the male
than in the female. No certain answer can be
given to these questions; but we ought to be
cautious in assuming that knobs and various
fleshy appendages cannot be attractive to the
female, when we remember that with savage
races of man various hideous deformities—
deep scars on the face with the flesh raised into
protuberances, the septum of the nose pierced
by sticks or bones, holes in the ears and lips
stretched widely open—are all admired as ornamental.
Whether or not unimportant differences between
the sexes, such as those just specified,
have been preserved through sexual selection,
these differences, as well as all others, must
primarily depend on the laws of variation. On
the principle of correlated development, the
plumage often varies on different parts of the
body, or over the whole body, in the same manner.
We see this well illustrated in certain