y early. But the fact
of the matter is that it is rather the minority of girls who
spontaneously exhibit the traditional stigmata of the natural girl.
The doll-cherishing, housekeeping imitator of mother is another story.

At puberty arise the most exquisite cases of life crisis dependent
upon hormonic crisis. The boy becomes restless, irritable and
quick-tempered when his thyroid and adrenals respond to the call of
the interstitial cells. If they do not, he will become dull, heavy,
lazy and listless. The girl correspondingly is transformed into a
vivacious, gay, nervous and apprehensive butterfly, or a sedate,
dreamy, bashful, or even morose moth. It is interesting to note that
poise, mental equilibrium, is not established until physical growth
ceases, marked by a cessation of growth of the long bones known as
ossification of the epiphyses. Poise seems to be controlled by the
ante-pituitary. The growth of the long bones is also dominated by the
ante-pituitary. It would seem as if, its secretion dedicated to the
one function, could not be available for the other. So it happens that
those in whom growth ceases early (probably because of an earlier
and more vigorous invasion of the internal secretion system by the
interstitial cell product), develop mental maturity more rapidly and
possess more of it than those in whom growth continues. The acumen and
salacity of certain dwarfs is proverbial. The puberty phenomena
teach that sex crises of every sort are dependent fundamentally upon
fluctuations, periodic or aperiodic, of the sex index, as we have
defined it.

THE DETERMINING FACTORS OF SEX LIFE

The material summarized in the preceding paragraphs furnish some
slight inkling of the vast dominion of Sex, in all its relations,
somatic and spiritual, over which the glands of internal secretions
rule. The founder of modern pathology, Virchow, said that woman is
woman because of her ovaries. He meant that woman is a woman, the sort
of woman she specifically is, because of her internal secretions. But
no divine decree has laid down a line of cleavage between man and
woman. There are fundamental constitutional differences between man
and woman. But it is just as true that man is man because of _his_
internal secretions.

We have seen that the concepts of Man and Woman are the end-points of
a curve including variations of every possible combination that are
embraced in the construction of a sex index. This sex index is not an