manifests itself in a host of
guises and disguises. Femininity in a woman, the womanly woman, or the
eternal feminine, may indeed be defined by the degree of somatic and
psychic exhibitionism she presents. A woman who has a delicate skin,
lovely complexion, well-formed breasts and menstruates freely will be
found to have the typical feminine outlook on life, aspirations
and reactions to stimuli, which, in spite of the protests of our
feminists, do constitute the biologic feminine mind. Large, vascular,
balanced ovaries are the well-springs of her life and personality.
On the other hand, the woman who menstruates poorly or not at all
is coarse-featured, flat-breasted, heavily built, angular in her
outlines, will also be often aggressive, dominating, even enterprising
and pioneering, in short, masculinoid. She is what she is because she
possesses small, shrivelled, poorly functioning ovaries. Between these
two types all sorts of transitions exist, according as the other
endocrines participate in the constitutional make-up. But no better
examples could be given, off-hand, of the determining stamp of the
internal secretions upon mind, character and conduct.

INSTINCT AND BEHAVIOUR

The sex instinct, analyzed as an endocrine mechanism, provides the
clue to the understanding of all instinct and behaviour. If the
post-pituitary regulates the maternal instinct, then its correlates:
sympathy, social impulses, and religious feeling, must be also
influenced, and so is furnished another example of a chemical control
of instinctive behaviour. McDougall, once of Oxford, now of Harvard,
introduced into psychology the idea of the simple instinct as a unit
of behaviour, regarding the most complex conduct as a compounding of
instincts. The instinct itself he analyzed into three elements: a
specific stimulus-sensation, an emotion following, all ending in a
particular course of muscular reaction. Translated into endocrine
terms, what happens may be pictured as a series of chemical events.

When the activity of a ductless gland rises above a certain minimum,
its hormones in the blood sensitize, as a photographic plate is
sensitized, a group of brain cells, to respond to a message from
the outside world, with a definite line of conduct. There is a
registration by the brain cells of the presence of the specific
stimulus. Then there is communication by them with the endocrine
organs. As a result, some of them are moved to further secretion,