activity in the female organs for at least seventeen days, they have ample time to exert their energies.  The fact that impregnation sometimes occurs without rupture of the hymen is not decisive evidence that there has been no penetration, as the hymen may dilate without rupturing; but there seems no reason to doubt that conception has sometimes taken place when ejaculation has occurred without penetration; this is indicated in a fairly objective manner when, as has been occasionally observed, conception has occurred in women whose vaginas were so narrow as scarcely to admit the entrance of a goose-quill; such was the condition in the case of a pregnant woman brought forward by Roubaud.  The stories, repeated in various books, of women who have conceived after homosexual relations with partners who had just left their husbands’ beds are not therefore inherently impossible.[119] Janke quotes numerous cases in which there has been impregnation in virgins who have merely allowed the penis to be placed in contact with the vulva, the hymen remaining unruptured until delivery.[120]

It must be added, however, that even if the semen is effused merely at the mouth of the vagina, without actual penetration, the spermatozoa are still not entirely without any resource save their own motility in the task of reaching the ovum.  As we have seen, it is not only the uterus which takes an active part in detumescence; the vagina also is in active movement, and it seems highly probable that, at all events in some women and under some circumstances, such movement favoring aspiration toward the womb may be communicated to the external mouth of the vagina.

Riolan (Anthropographia, 1626, p. 294) referred to the constriction and dilation of the vulva under the influence of sexual excitement.  It is said that in Abyssinia women can, when adopting the straddling posture of coitus, by the movements of their own vaginal muscles alone, grasp the male organ and cause ejaculation, although the man remains passive.  According to Lorion the Annamites, adopting the normal posture of coitus, introduce the penis when flaccid or only half erect, the contraction of the vaginal walls completing the process; the penis is very small in this people.  It is recognized by gynaecologists that the condition of vaginismus, in which there is spasmodic contraction of the vagina, making intercourse painful or impossible, is but a morbid exaggeration of the normal contraction which occurs in sexual excitement.  Even in the absence of sexual excitement there is a vague affection, occurring in both married and unmarried women, and not, it would seem, necessarily hysterical, characterized by quivering or twitching of the vulva; I am told that this is popularly termed “flackering of the shape” in Yorkshire and “taittering of the lips” in Ireland.  It may be added that quivering of the gluteal muscles also takes place during detumescence, and that in Indian medicine this is likewise regarded as a sign of