angement of status and influence among the ductless
glands. Bisexuality preceded monosexuality in the animal pedigree, and
co-exists with it even at the highest points of the genealogical tree.

While from the standpoint of the species, the criterion of the sex
classification of its members will depend upon their capacity to
fertilize or to be fertilized, a quality that may, therefore, be
spoken of as the primary sex character, a number of other traits have
been evolved by sexual selection, the secondary sex traits. They have
come to be just as important, to the individual, as far as his or her
consciousness of sex attitudes and reactions to it are concerned. The
terms primary and secondary sex characteristics, though inapt, must be
allowed to stand.

These accessory sex-serving traits undoubtedly survived because of
their usefulness in external adornment for attracting attention in
courtship, in the metabolic requirements of sex combat and the sex
act, and in the necessities of caring for the young, until well-grown.
The rooster's comb and spurs, the male frog's claspers, the stag's
antlers, and so on, are familiarly and obviously so useful. Besides
there are fundamental differences in inner physiology. The human male
consumes more oxygen than the female per minute, since he has more red
corpuscles in his blood. In some caterpillars the blood is yellow in
the males and green in the females. W.I. Thomas has devoted an essay
of some fifty pages to a review of the organic differences between man
and woman. The ordinary criteria, employed every day by the man in the
street to distinguish man from woman may be arranged as follows:

_Man_ _Woman_

Hair on face Hairless face
Skin coarse and lean Skin fine and plump
Muscles powerful Relatively weak
Bones heavy Bones light
Aggressive--bass voice Reserved--treble voice

THE ROLE OF THE OVARIES

While the primary sex characters, as such, are present and
distinguishable from birth, quite the opposite holds for the secondary
sex traits. During childhood they are in abeyance or at least pretty
sharply suppressed. Girls and boys who are permitted to dress alike,
to play the same games and among whom no consciousness of sex is
encouraged are often difficult to tell apart. The boys will be boys,
and most of the girls tom-boys.

With puberty comes a marked change of attitude toward the oth