On the Secrets of Women

and because their menses are extremely terrestrial, therefore it follows the color of the earth. Because color is a secondary quality, left behind by the primary qualities. Example: just as we see when heat acts upon humidity and does not sufficiently consume the humidity, a green color is left behind, as in pears and apples. And if cold predominates, the color is white, but if heat predominates, a black color is left behind, as is evident in pepper, and so it is of other similar things.

The second doubt can be whether the menses flow through the anus, and this in the manner of defecation, or through the vulva, in the manner of the ejection of urine. To this it must be said briefly that it flows through the vulva in the form of raw and thin blood.

Here the author poses the second doubt, as is evident in the text. And it is answered to the doubt that for women who are much corrupted, whose anus and vulva are one opening, the menses flow through the anus, but in a state of health and good digestion, then they do not flow through the anus, but through the vulva.

Thirdly, it is doubted why the menses, which are the superfluity of food, flow in women, and sperm does not in men, which is also the superfluity of food. To this doubt it must be said that a woman is cold and humid by nature: a man, however, is hot and dry. Now, it is of the nature of the humid to flow (4th Metaphysics), and especially the humidity which is in women is watery. But in men