CHAPTER XIII. WHENCE ARISETH BARRENNESS IN WOMEN, AND IMPOTENCY IN MEN?
The physicians maintain, that sterility in women can arise from the womb; for if it be after any ways thus affected, there will be a barrenness,—if it be more condensed, or more thin, or more hardened, or more callous, or more carneous; or it may be from languor, or from an atrophy or vicious condition of body; or, lastly, it may arise from a twisted or distorted position. Diocles holds that the sterility in men ariseth from some of these causes,—either that they cannot at all ejaculate any sperm, or if they do, it is less than nature doth require, or else there is no generative faculty in the sperm, or the genital members are flagging; or from the obliquity of the yard. The Stoics attribute the cause of sterility to the contrariant qualities and dispositions of those who lie with one another; but if it chance that these persons are separated, and there happen a conjunction of those who are of a suitable temperament, then there is a commixture according to nature, and by this means an infant is formed.
CHAPTER XIV. HOW IT ARISES THAT MULES ARE BARREN.
Alcmaeon says, that the barrenness of the male mules ariseth from the thinness of the genital sperm, that is, the seed is too chill; the female mules are barren, because the womb does not open its mouth (as he expresses it). Empedocles, the matrix of the mule is so small, so depressed, so narrow, so invertedly growing to the belly, that the sperm cannot be regularly ejaculated into it, and if it could, there would be no capacity to receive it. Diocles concurs in this opinion with him; for, saith he, in our anatomical dissection of mules we have seen that their matrices are of such configurations; and it is possible that there may be the same reason why some women are barren.
CHAPTER XV. WHETHER THE INFANT IN THE MOTHER'S WOMB BE AN ANIMAL.
Plato says, that the embryo is an animal; for, being contained in the mother's womb, motion and aliment are imparted to it. The Stoics say that it is not an animal, but to be accounted part of the mother's belly; like as we see the fruit of trees is esteemed part of the trees, until it be full ripe; then it falls and ceaseth to belong to the tree; thus it is with the embryo. Empedocles, that the embryo is not an animal, yet whilst it remains in the belly it breathes. The first breath that it draws as an animal is when the infant is newly born; then the child having its moisture separated, the extraneous air making an entrance into the empty places, a respiration is caused in the infant by the empty vessels receiving of it. Diogenes, that infants are nurtured in the matrix inanimate, yet they have a natural heat; but presently, when the infant is cast into the open air, its heat brings air into the lungs, and so it becomes an animal. Herophilus acknowledgeth that a natural, but not an animal motion, and that the nerves are the cause of that motion; that then they become animals, when being first born they suck in something of the air.