We append the account given by _Pfannenstiel_ regarding the ovarian follicles. He writes: “In correspondence with the especial function of the female reproductive gland, which is to bring to maturity and to evacuate only after the lapse of a considerable period and at successive intervals, the ova which it has contained from the very outset, we find that primitive follicles continue to exist in the ovary up to the very end of the period of sexual activity, though naturally in diminishing numbers; and the size and shape of these primitive follicles remain nearly identical throughout the various periods of life. As the follicle ripens, the epithelium grows, the cells becoming cubical with a rounded nucleus, and increasing in number by cell-division, so that several layers are formed. As soon as these layers are three or four in number, a space, at first slit-shaped, forms in the epithelium on the peripheral surface of the ovum; this space is filled with fluid, known as the liquor folliculi; the peripheral layer of cells, the membrana granulosa, is thus separated from the mass of epithelial cells immediately enveloping the ovum, the discus proligerus, which is situate in the side of the follicle adjacent to the hilum of the ovary. By the increase of the liquor folliculi the graafian follicle is formed, a vesicle the envelope of which is formed by the multilaminar membrana granulosa, whilst in the pole of the vesicle directed toward the hilum ovarii is the ovum imbedded in the mass of cells forming the discus proligerus, a mass which has the form of a truncated cone. The liquor folliculi is formed by the epithelium, the nuclei of which disappear by chromatolysis or by simple atrophy whilst the cell-bodies liquefy in consequence of albuminous, not fatty, degeneration (_Schottländer_). Within the epithelium of the follicle we find the faintly glistening epithelial vacuoles of _Fleming_, likewise cells which liquefy and assist in increasing the bulk of the liquor folliculi. This liquor is a thin, serous fluid, and contains albumin. * * * Every graafian follicle has a bilaminar investing membrane, which is formed by the ovarian stroma. * * * The ovum of the growing follicle increases in size very slowly indeed, attaining on the average, according to _Nagel_, a diameter of 165 to 170 µ, it retains its zona pellucida, the greater part of the protoplasm of the cell is transformed into deutoplasm (food-yolk, or yolk-granules), the nucleus assumes an eccentric position. Between the zona pellucida and the cell-body a narrow perivitelline space appears. The ovum is then full-grown, but not yet fully prepared for fertilization; for this, maturation is required, certain changes in the germinal vesicle, which occur after the bursting of the follicle. * * * As a rule each follicle contains a single ovum. But two and even three ova have beyond doubt been observed in one follicle.”