ence, food alone. But
with the sexual life came a conflict for sex pleasure, a competition
among members of the same species for the same individual as their sex
partners. The result was the introduction of a factor in evolution
which Darwin examined so closely in the "Descent of Man."

The sex conflict has been the cause for the origin and the survival
of certain physical and mental traits, helpful in sex attraction, sex
combat, the growth of the embryo, and the nutrition and safety of the
young of a species,--in short, the whole process of sexual selection.
The proportions of the skeleton, the distribution of hair and fat, the
construction of organs of attack and defense, the color of the skin,
the cyclic processes of preparation for impregnation, the oestrus or
heat period in animals, the menstrual period in the human being, the
psychic reactions to danger and combat have all been thus determined.
That man is bearded while woman is not,--that woman has potentially
functional breasts while man has not,--the aggressive pugnacity of
man contrasted with the more passive timidity of woman, have all been
evolved in the sex struggle, surviving because most effective in that
struggle. These so-called secondary sexual characteristics are an
expression of the influence of the internal secretion of the gonads,
or the interstitial glands. Some call them puberty glands, because
their ripening initiates puberty.

We know that these interstitial glands, to stick to that name, (rather
than to the name of the puberty glands, since they serve not only
to induce puberty but to maintain maturity) are the actual primary
dictators of the process by which male and female are distinguished,
if not created. Castration was probably the first surgical operation
carried out for experimental purposes, suggested no doubt by a
curiosity concerning its effects. Trepanning of the skull, the
geologic record indicates, was done even by the cave man. But as an
experimental operation, castration seems to hold the primary position
in the annals of surgery.

Its effects noted, the satisfaction of one of the lower human
instincts, jealousy, popularised it. From the days of Semiramis,
eunuchs have been commonplace figures of the East, their function
definite: to guard the harems of the powerful. The age of Abdul Hamid
witnessed no diminution of the barbaric tortures by which children are
prepared for the profession. It is to the credit of England that in