The Descent of Man

selection— Colour acquired for the sake of protection—Colour,
though common to both sexes,
often due to sexual selection—On the disappearance
of spots and stripes in adult quadrupeds—On
the colours and ornaments of the
Quadrumana—Summary.
Quadrupeds use their voices for various purposes,
as a signal of danger, as a call from one
member of a troop to another, or from the mother
to her lost offspring, or from the latter for
protection to their mother; but such uses need
not here be considered. We are concerned only
with the difference between the voices of the
sexes, for instance between that of the lion and
lioness, or of the bull and cow. Almost all male
animals use their voices much more during the
rutting-season than at any other time; and some,
as the giraffe and porcupine (1. Owen, 'Anatomy
of Vertebrates,' vol. iii. p. 585.), are said
to be completely mute excepting at this season.
As the throats (i.e. the larynx and thyroid bo-