Sterility must not be confounded with impotency. Many women are barren, but very few are impotent; while, on the contrary, many men are impotent who ought not, on that account, to be regarded as barren. In either sex impotency is present when from whatever cause an individual cannot concur in the sexual contact. Sterility exists when the contact, after having been regularly accomplished, is followed by no productive result. With the exception of those pathological cases in which deformities are sometimes, but very rarely, met with, it may be affirmed that woman is never impotent, for her organization opposes it. Radical impotence, in fact, results in the female from the complete absence, or the occlusion simply, of the vagina. Now, these cases are extremely rare, and may there fore be considered as exceptions or as real monstrosities. As the causes of sterility in women are numerous and of various kinds, we shall briefly enumerate them. The absence of ovaries or their deceased state are the radical cause of sterility. These causes may be suspected but not cured. When there is no uterus, still fecundation and pregnancy are not impossible, since extra-uterine pregnancies are occasionally observed, that is to say, cases in which the product of conception has escaped the uterus, end proceeded to establish itself in some point of the lower belly. Neither is the vagina indispensable, for cases are cited of the contraction of this organ accompanied by the rectovaginal fistula, in which fecundation is effected, although the fecundating fluid had been confined to the rectum. Female masturbation is another rife cause of barrenness in women. If it be true that the number of eggs is limited, and that there are not more than from 15 to 20 in each ovary, it is evident that sterility must ensue when these 15 or 20 eggs have been detached without fecundation. If, on the contrary, new eggs are continually secreted by the ovaries, it is equally evident that the secretory action must, sooner or later, become exhausted by the over excitement caused by the indulgence above mentioned. Another very great cause of sterility, and which must be of frequent occurrence, is found in the obstructed or choked-up state of the Fallopian tubes. These passages, which establish the communication between the ovary and the uterus, may be obstructed by inflammation, either acute or chronic, to which they must be subject in all diseases to the abdomen, as well as by frequent excitement. Morgagni speaks of certain women of the town, with whom the Fallopian tubes were completely obliterated by the thickening of the parietes or sides, an evident consequence of the continual orgasm in which they were kept by immoderate indulgence in coition. The absence of menstruation almost always induces barrenness. Cases are, notwithstanding, reported in which women have their menses during pregnancy, but these are exceptions which so far from invalidating the rule, confirm it.