A mode of prevention, already hinted at in the section on fecundation, and having at least a physiological basis, is founded on the theory of the monthly arrival of the ripe ovum in the womb. It was shown that, in the last half of the menstrual interval, a period of about nine days intervened in which, under ordinary circumstances, no impregnation can occur. But there are causes to thwart even this theory. It requires for a perfect connection, mutual adaptation of the sexual organs, mutual love, and mutual intensity of passion. Connection under other circumstances is unenjoyable, distasteful, at least to the woman, and so barren of the higher spiritual or psychical delight as to border on the merely mechanical act of masturbation. Few women can undergo the process of the sexual act without becoming sexually excited, and this excitement hastens the premature ripening and expulsion of the germ-cell; so that impregnation may take place even within the period specified.

Of course, if a woman—as many do, when sexual love does not enter into the union—lie perfectly cold and passionless, the man, during this brief period of exemption, may enjoy himself to his heart's content without danger; but, so far as the genesic pleasure of the act goes, he might, as 1 have intimated, nearly as well practise self-indulgence by the hand.