upon the post-pituitary, the most
active of the feminizing uterus-disturbing endocrines. Until at last
something happens that puts the placenta out of commission in this
function of restraint, and the long bottled up post-pituitary
secretion explodes the crisis apparent as the process of labor.

A condition of self-poisoning often occurs in pregnancy, with symptoms
orchestrating from mild notes like nausea and vomiting to the high
keys of convulsions and insanities. They represent what happens when
an unbalanced endocrine system is attacked by the placenta. Depending
upon where in the internal secretion chain the weak point, the
Achilles' heel spot, will be found, the nature of the reaction will
vary. And even after labor, after the explosive crisis, so much of the
reserve endocrine materials may be consumed, that an actual mania or a
chronic weakness may come in its wake.

Yet the placental secretion must not be looked upon as something
wholly evil in its potentialities. Without enough of it to hold the
uterus stimulating endocrines, particularly the post-pituitary, in
check, still-birth results. If there is enough, and not too much of
it, the woman will not feel ill at all, or perhaps only transiently,
but will be possessed of a curious feeling of drowsy content and
passive, relaxed happiness. Let there be relatively too much of it,
too little of the other glands, and the grosser transfigurations and
ailments of the child-bearing period follow.

THE MAMMARY GLANDS

Once pregnancy is terminated by labor, the placenta is expelled from
the body as the after-birth. The placenta removed, a new arrangement
of the balance of power among the endocrines becomes necessary. But a
new-comer appears upon the scene to take up the function left vacant
by the absent placenta. This new-comer is the secretion of the
activated breasts, the mammary glands. They make for a persistence
of the state of equilibrium among the endocrines attained during
pregnancy.

The mammary glands are typical glands of external secretion. They make
the milk and pour it out of the breasts through little canals into the
mouth of the suckling. Yet evidence forces us to conclude that they
are also glands of internal secretion, that their internal secretion
substitutes to a certain extent for the loss of that of the placenta
but not quite.

What seems to happen in fact, is this: the corpus luteum secretion
stimulates the dormant cells of the mammary gla