Histological observations on post-ovulatory follicles in the domestic fowl

　ニワトリのPost-Ovulatory Follicle を組織学的に観察した.卵胞は排卵とともに収縮し，スチグマに破裂口を有するやや扇平な囊状となる.その後次第に萎縮し瘤状となり，排卵1ヶ月後には卵巣実質に吸収されて，肉眼的には不明となる.
　顕微鏡的に観察すると，排卵直後の卵胞腔は空虚であるが，卵胞腔lこいわゆるVacuolated Cell が現われる.このVacuolated Cell が結局は卵胞腔を充填する. Vacuolated Cell は強くズダン陽性である.Vacuolated Cell は卵胞上皮細胞，卵胞膜内層にある卵胞膜細胞および卵胞膜の線維細胞の変性によって生じたものである.
　排卵に際して，卵胞上皮は基底膜とともに広範囲に卵胞膜から剥離する.基底膜は著しく厚くなる.また卵胞膜の内側に出血をきたす.

The post-ovulatory ovarian follicle of the hen was studied histologically for regressive changes. The results obtained are as follows.

1. After ovulation the follicle shrank to a fiat thin-walled sac with an opening at the stigma. The ruptured follicle underwent progressive atrophy and disappeared ultimately into the stroma of the ovary.
2. After ovulation the empty follicular cavity was filled with an aggregative mass of vacuolated cells, the vacuoles of which were strongly sudanophilic. The vacuolated cells were derived from epithelial cells, follicular cells located in the internal theca, and fibrocytes present in the internal and external theca.
3. The basement membrane was detached from the internal theca at the time of ovulation. It thickened and wrinkled extensively after ovulation. It was rich in mucopolysaccharides.
4. Varying degrees of hemorrhage occurred in the inner wall of the follicle at the time of ovulation. Proliferation of capillaries was presented in the injured area of the inner wall of the follicle.
5. The blood vessels of the follicular wall underwent gradual atrophy after ovulation. In the course of regression, a large quantity of mucopolysaccharides was demonstrated in the vascular wall.