t controllers of elementary sexuality and the specific sex
traits of male and female. Beginning with Berthold back in the first
half of the nineteenth century, who studied the fowl, a number of
observations have been made on the effects of excision, translocation
and transplantation of these glands.

The results of the experiments and observations can be summed up as
follows: if the male individual is castrated before puberty, that is,
before the advent of the sexual life, secondary sex qualities do not
develop. In males, the generative organs do not grow, hair on the face
does not appear, hair elsewhere on the body remains generally scanty,
the voice continues as high-pitched as the child's, there is more
or less muscle weakness, obesity, and mental sluggishness. In other
words, we have an effeminate man, technically a eunuch. In the
castrated female, the pelvis does not grow to the normal feminine
size, the breasts do not swell as they should, more or less hair comes
out on the face, the voice is low-pitched, and tends to be rather
husky, the legs are longer, and again, the mentality is dulled. That
is, a masculine sort of woman is produced.

In short, the castrated male takes on a feminine type, and the
castrated female, a male type. In either case there is also an
infantilism, a retention of the infantile mental traits, a lack of
development of the adult mental attitudes and reactions. Now, if
in the castrated male is transplanted an ovary, the positive
characteristics of the female are evoked, such as enlarged mammary
glands, and a tendency to secretion of milk. Experiments have also
been reported in which a uterus was also placed in such an animal,
with a means of entry, and pregnancy followed. If in the castrated
female a testicle is planted, the masculine traits become much more
marked and striking. A direct exchange of the male and female
roles can thus be achieved. Castration after puberty cannot modify
profoundly structures like the skeleton which are already completed.
Yet it may unquestionably bring about definite retrogressive changes
in the secondary sex characters: reduction or loss of virility,
diminution of facial and body hair, and a general presenility or
hastening of senility.

How remarkably these interstitial cells influence the entire structure
and vitality of the organism is indicated by these facts. How much
they have to do with sexual impulses, sexual excitement, and sexual
desire, what th