Chapter II.

1. The catamenia appear when the moon is on the wane, from which some persons would argue that the moon is a female, for the purification of women and the waning of the moon occur together, and repletion occurs again in both after the purification and waning. In few women the catamenia occur every month, but in most at every third month. Those in whom they continue for only two or three days escape with ease: it is more difficult for those in whom it continues for a longer time, for they suffer during the whole period. In some the purification takes place all at once, in others by degrees; in all, however, the pain is considerable as long as they are present. In many women, when the catamenia are nearly ready to appear, the womb suffers so much from strangulation and disturbance, until they are discharged.

2. Conception naturally takes place immediately after this discharge in women, and those who do not then conceive, are usually barren. Some women, however, who have never menstruated, conceive. Such persons contain in themselves as much of the fluid as is usually left behind after the purification, but not so much as to make its appearance externally. Some women in whom the uterus has closed immediately after the purification, conceive even while menstruating, but do not conceive afterwards. The catamenia sometimes occur even in pregnant women. Such women usually bear imperfect children, and their offspring either do not grow up, or are weakly.

3. It frequently happens that from the want of sexual intercourse, or from youth and the period of life, or from long abstinence, the uterus descends, and the catamenia occur several times in the month, until they conceive; after which the parts return to their proper place: and sometimes even in women with a good habit of body, if the humours are abundant, an effusion of the semen takes place if it is too moist.

4. It has already been observed that this purification is more abundant in women than in any other creature. In animals that are not viviparous no symptoms of anything of the kind occur, for this superfluous matter is returned into their own body, for in many the females are superior to the males in size, and in many it is turned to the formation of plates, or scales, or abundance of feathers. In viviparous animals with feet, it is turned to the formation of hair and bulk of body (for man is the only animal that is smooth), or of urine; for in almost all animals this secretion is thick and abundant. In women, on the contrary, all the superfluous matter of the body is directed to this purification.

5. The case of the male is the same, for in proportion to his size, man emits more semen than other animals; (wherefore, also, man is the smoothest of all animals,) and among men those which abound in humours, and are not very full fleshed, and fair men more than dark ones. So also among women. For in those that are full fleshed, the greater part of the secretion goes to the supply of the body, and in the act of sexual intercourse, fair women have naturally more seminal fluid than dark ones. Liquid and acid foods also increase this kind of intercourse.