extensively with mammals than with birds; but weapons, such as horns
and tusks, have often been transmitted either exclusively or much more
perfectly to the males than to the females. This is surprising, for, as
the males generally use their weapons for defence against enemies of
all kinds, their weapons would have been of service to the females. As
far as we can see, their absence in this sex can be accounted for only
by the form of inheritance which has prevailed. Finally, with
quadrupeds the contest between the individuals of the same sex, whether
peaceful or bloody, has, with the rarest exceptions, been confined to
the males; so that the latter have been modified through sexual
selection, far more commonly than the females, either for fighting with
each other or for alluring the opposite sex.
PART III.
SEXUAL SELECTION IN RELATION TO MAN, AND CONCLUSION.
CHAPTER XIX.
SECONDARY SEXUAL CHARACTERS OF MAN.
Differences between man and woman Causes of such differences and of
certain characters common to both sexes Law of battle Differences in
mental powers, and voice On the influence of beauty in determining the
marriages of mankind Attention paid by savages to ornaments Their ideas
of beauty in woman The tendency to exaggerate each natural peculiarity.
With mankind the differences between the sexes are greater than in most
of the Quadrumana, but not so great as in some, for instance, the
mandrill. Man on an average is considerably taller, heavier, and
stronger than woman, with squarer shoulders and more plainly-pronounced
muscles. Owing to the relation which exists between muscular
development and the projection of the brows (1. Schaaffhausen,
translation in Anthropological Review, Oct. 1868, pp. 419, 420,
427.), the superciliary ridge is generally more marked in man than in
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