The association between breasts and womb is so obvious that it has not escaped many savage peoples, who are often, indeed, excellent observers. Among one primitive people at least the activity of the breast at impregnation seems to be clearly recognized. The Sinangolo of British New Guinea, says Seligmann (_Journal of the Anthropological Institute_, July-December, 1902, p. 298) believe that conception takes place in the breasts; on this account they hold that coitus should never take place before the child is weaned or he might imbibe semen with the milk.
It is natural to assume that this connection between the activity of the womb and the glandular activity of the breasts is a nervous connection, by means of the spinal cord, and such a connection certainly exists and plays a very important part in the stimulating action of the breasts on the sexual organs. But that there is a more direct channel of communication even than the nervous system is shown by the fact that the secretion of milk will take place at parturition, even when the nervous connection has been destroyed. Mironoff found that, when the mammary gland is completely separated from the central nervous system, secretion, though slightly diminished, still continued. In two goats he cut the nerves shortly before parturition and after birth the breasts still swelled and functioned normally (_Archives des Sciences Biologiques_, St. Petersburg, 1895, summarized in _L'Année Biologique_; 1895, p. 329). Ribbert, again, cut out the mammary gland of a young rabbit and transplanted it into the ear; five months after the rabbit bore young and the gland secreted milk freely. The case has been reported of a woman whose spinal cord was destroyed by an accident at the level of the fifth and sixth dorsal vertebræ, yet lactation was perfectly normal (_British Medical Journal_, August 5, 1899, p. 374). We are driven to suppose that there is some chemical change in the blood, some internal secretion from the uterus or the ovaries, which acts as a direct stimulant to the breasts. (See a comprehensive discussion of the phenomena of the connection between the breasts and sexual organs, though the conclusions are not unassailable, by Temesvary, _Journal of Obstetrics and Gynæcology of the British Empire_, June, 1903). That this hypothetical secretion starts from the womb rather than the ovaries seems to be indicated by the fact that removal of both ovaries during pregnancy will not suffice to prevent lactation. In favor of the ovaries, see Beatson, _Lancet_, July, 1896; in favor of the uterus, Armand Routh, "On the Interaction between the Ovaries and the Mammary Glands," _British Medical Journal_, September 30, 1899.