With the prolonged activity of the corpus luteum during pregnancy, prolonged stimulation of the breasts occurs.  The secretion of the post-pituitary would now cause the change from the internal cell secretion to milk.  But it is inhibited from so doing by the placenta.  When the placenta is removed, after labor, the post-pituitary can act, and a free flow of milk is established.  However, to counterbalance this, and to prevent the post-pituitary from overacting, the breasts secrete a hormone with an action like that of placenta, but not so strong, which tends to inhibit the ovary.  So is put off the imposition of a pregnancy upon a period of lactation, obviously bad for mother, infant, and embryo.  We have here an exquisite sample of the checks and compensations which make for a self-balancing of the whole endocrine system.

CRITICAL AGES

The Dangerous Age is a phrase coined by a Scandinavian writer as a more dramatic euphemism for the time of life when sex function ceases, the climacteric.  As a matter of fact, the age of adolescence is just as much of a dangerous age as the age of deliquescence.  The only difference between them is that the dangers of the one have been hushed up, the dangers of the other well boomed and advertised.  Both are dangerous to the individual, because both are periods of instability and readjustment of the cells, particularly the brain cells, to a deranged endocrine system and blood chemistry.

Moral attitudes differ at the two ages, not so much as an effect of experience, as expressions of different visceral pressures produced by newly dominant internal secretions.  So in Eugene O’Neil’s play, “Diff’rent,” we see the woman Emma Crosby as she is in her youth, when her ovaries have budded and bloomed for only a few years, and her other endocrine influences are still dormant.  She breaks off her engagement to Captain Caleb Williams on the eve of her wedding because she is informed of the episodes of a sex affair he was involved in on his last voyage, under circumstances not discreditable to him.  The next act shows her thirty years later when, as an elderly spinster, she is passing through the climacteric, and is in the state of sexual hyperesthesia some women are afflicted with before the menopause.  It is as if the ovaries and the accessory sex internal secretions erupt into a sort of final geyser before they are exhausted.  So the captain, ever faithful, finds her, and discovers to his horror that she is a thousand times more like other women than he has ever been like other men.  Because of his ignorance of the underlying chemical basis for the transfiguration, tragedy follows.  Critics may cackle about a sex starved woman, who has repressed her natural desires, and hail the play as a contribution to the Freudian clinics.  As a matter of fact, it is a study of libido variation, with endocrine variation, at two stages of the inner chemical life of a woman.