Cancer, on the other hand, if we collect all that comes under this denomination, is not unusual.

a. The most frequent form is areolar cancer in the above-described shape of areolar hydrops ovarii: the conversion of the peripheral follicles of the ovary into large sacs, is a peculiarity which but rarely presents itself in other tissues. We have already alluded to all the important points connected with this subject.

3. Medullary carcinoma is less frequent than the former. There are two varieties. The first occurs in the shape of rounded adventitious growths, varying in size from a goose's egg, to a child's head, and invested with a fibrous sheath; it sometimes perforates the latter, and grows freely into the peritoneal cavity. In the interior we occasionally find large masses of cellular tissue traversing the substance of the tumors in the shape of septa, and inducing considerable density of the mass; at other times the entire ovary appears infiltrated with soft encephaloid matter, so as to present fluctuation. The carcinomatous matter is either genuine white cancer, or it contains pigment-cells, which vary in arrangement and number; in the latter case it is brown or black, spotted or striated, or black throughout (cancer melanodes). It occasionally is combined with the formation of cysts, the latter being either developed on the free surface of the peritoneal sheath of the ovary, or underneath the latter, and in the peripheral layers of the stroma.

This variety occurs in complication with peritoneal cancer, with uterine, mammary, and ventricular cancer, with cancer of the lymphatic glands and the rectum, and universal cancerous deposit. Close adhesions are sometimes formed between it and the adjoining cancerous rectum, so that there is often considerable difficulty in ascertaining which of the two organs is the primary seat of disease. Both ovaries are very often affected.

In the second variety, racemose, fimbriated, fibrous, vascular excrescences, containing a milky or creamy juice, or an encephaloid pulpy mass, form on the internal surface of the peripheral follicles of areolar cancer, or of one of the sacs of the compound cysts, or even upon the internal surface of a small primary cyst. They are often very numerous and attain a considerable length; they become condensed into large masses, and after perforating the parietes of the cyst, sprout through it.

This form is often, though not invariably, coexistent with areolar cancer of the ovary or of other organs.

y. Fibrous cancer (scirrhus) occurs very rarely in the ovary.