On the Secrets of Women

...or it is the end of the vulva, and thus the womb matrix: the uterus, seen as the generative "mother-place" is closed like a purse, so that according to Avicenna original: "Avicennam"; a 10th-century Persian physician whose "Canon of Medicine" was the standard textbook for medieval doctors not even a needle could enter, because the womb rejoices in the heat it has received and is unwilling to lose it. Note that a woman emits her menstrual fluid original: "menstruum"; here referring to the female's contribution to conception and also receives the man's, and thus she takes more pleasure in sexual intercourse original: "coïtu" than the man himself.

But a doubt arises: whether someone could father a child if their testicles were cut off? And it seems not, because the seminal vessels, through which the seed must be carried, would be lacking. On the contrary, it has been proven by experience, for a bull can father offspring even after his testicles are cut off. I say that, indeed, he could still generate, because he can still emit spermatic matter, although not as effectively. Wherefore, if seed emitted onto the ground were placed in the womb, it would be possible for the woman to conceive.

Hence it often happens that in a bath where a man ejaculates while a woman is present, she conceives without direct intercourse, because the vulva is highly attractive meaning it "draws in" or exerts a magnetic-like pull on the seed, and because the seed is still vigorous and has not evaporated; therefore, it could produce a fetus, and this has been proven by experience. For if a cat were to ejaculate upon sage original: "salvia", and someone were to eat that sage, then from that sperm, cats would be generated in the man’s belly, which cats would then have to be expelled by vomiting. This reflects a medieval belief in spontaneous generation or the idea that animal seeds could survive and grow as parasites if ingested.

Regarding this, it should be noted that the menstrual fluid in a woman is nothing other than "superfluous nourishment"—that is, extra nutrition that is not absorbed into the body's substance elsewhere, just as sperm is in men. And it is called "menstrual" in a woman for this reason: because it flows at least once in every month, once the woman has reached a certain age—that is, 12, 13, or 14 years old.