er sex.
Puberty is the time of ripening of the specific germ cells. It is
then the ovaries begin to secrete ova ripe for fertilization, and the
testes begin to secrete sperm ready to fertilize. Before this can
happen an event announced in the female by the onset of menstruation,
two conditions must be fulfilled in the endocrine history of the
individual. There must be a certain atrophy and retrogression of
the thymus gland, and there must likewise be a similar atrophy and
retirement of the pineal gland. Both of these involutions of the
glands of childhood must occur before the normal hypertrophy and
development of the sex glands and their secretions can start. Besides,
there must be a minimum activity of the thyroid, adrenal and pituitary
glands. Without them, below a certain minimum, the reproductive organs
and their secretions will remain infantile, causing a persistent
infantilism or delay of puberty.

Formerly there was ascribed to the ovaries, in a lump and without
qualification, an absolute despotism over the specifically feminine
functions of menstruation, gestation, parturition, and lactation.
Nowadays, we see its domain as a limited monarchy, if not indeed as
one sovereign state of a republic, a member equal but not superior to
the others of a board of directors. Its true business comes down to
two particular roles: first, the production of ova, and, second, the
secretion of a hormone or hormones. Over the other functions once
supposed its monopoly, all the ductless glands rule.

What concerns us now is its internal secretion or secretions. One of
them is known as lutein and it has never been chemically isolated
in its pure form. The existence of lutein, like the existence of
electricity, is an inference, something we are sure is there because
of its effects. It originates in a remarkable part of the ovary, the
corpus luteum. Besides, there are the products of the interstitial
cells, the creations of a special layer of cells around the ovum, the
membrana granulosa. They produce a substance tonic to the uterus.

When the ovaries are removed, there occurs an atrophy of the womb
muscle, due to loss of this tonic substance. This atrophy, accompanied
by an abolition of the normal periodic uterine contraction, makes
conditions unfavorable to pregnancy. It has been claimed that the
secretion of the corpus luteum is necessary for the complete progress
of a pregnancy. Cases are on record, however, of ovaries taken ou