Montgomery, Colomb, and Knehel, each, have recorded the birth of twins in women beyond the usual age of the menopause, and there is a case recorded of a woman of fifty-two who was delivered of twins.
Impregnation without completion of the copulative act by reason of some malformation, such as occlusion of the vagina or uterus, fibrous and unruptured hymen, etc., has been a subject of discussion in the works of medical jurisprudence of all ages; and cases of conception without entrance of the penis are found in abundance throughout medical literature, and may have an important medicolegal bearing.

There is little doubt of the possibility of spermatozoa deposited on the genitalia making progress to the seat of fertilization, as their power of motility and tenacity of life have been well demonstrated.

Percy reports an instance in which semen was found issuing from the os uteri eight and one-half days after the last intercourse; and a microscopic examination of this semen revealed the presence of living as well as dead spermatozoa.

We have occasional instances of impregnation by rectal coitus, the semen finding its way into an occluded vaginal canal by a fistulous communication.
Guillemeau, the surgeon of the French king, tells of a girl of eighteen, who was brought before the French officials in Paris, in 1607, on the citation of her husband of her inability to allow him completion of the marital function.

He alleged that he had made several unsuccessful attempts to enter her, and in doing so had caused paraphimosis.