EXPERIMENTAL PRODUCTION OF HYPOTYPICAL OVARIES. 99 



clears and polynuclears in stroma. Beginning secretion follow- 

 ing abortion. In this case the underfeeding was probably respon- 

 sible for the abortion. In the controls otherwise held under the 

 same conditions, but given sufficient food, pregnancy proceeded 

 normally. Ovaries, uterus and mammary gland corresponded 

 to the stage of the sexual cycle of this animal. 



Guinea Pig No. 2.- Weight Oct. 18, 464 grams; Nov. 18, 302 

 grams. Following this date it received a full ration of food for 

 a few days and on Nov. 25 it had regained a part of its loss, 

 weighing now 357 grams. Underfeeding was again resumed. 

 On Nov. 30, it weighed 303 grams and it was examined. Ovaries: 

 Tw r o young corpora lutea with dilated capillaries. There is in 

 the corpora lutea a central cavity surrounded by a little peripheral 

 connective tissue. Mitoses are found in the capillaries and in 

 the central connective tissue. Atretic yellow bodies with vacu- 

 oles and thick vessels are also present. Small and small-medium 

 good follicles with a very thin layer of granulosa which even 

 around the egg is imperfect. Some mitoses in the granulosa 

 cells. In other small-medium follicles granulosa is lost. Fol- 

 licles in various stages of connective tissue atresia. The uterus 

 shows a high cylindrical surface epithelium, glands with cuboidal 

 cells and a very cellular myxoid mucosa. The mammary gland 

 consists of good acini without mitoses; it presents an inter- 

 mediate character. Ovulation had taken place about 2-3^/2 

 days previous to the examination. It is probable that following 

 ovulation the ovaries ceased to develop normally and are becom- 

 ing hypotypical. The solution of granulosa cells in small- 

 medium follicles suggests such an interpretation. We may 

 assume that probably following the transitory gain in weight 

 a few days before examination ovulation occurred. For a con- 

 siderable period previous to the last ovulation, ovulation had 

 failed to take place, probably in consequence of the underfeeding. 

 We find therefore only remnants of degenerated corpora lutea, 

 representing the corpora lutea of the preceding cycle. The 

 underfeeding did not prevent mitotic division in various struc- 

 tures, nor did it prevent the development of a slightly pre- 

 deciduomatous condition of the uterine mucosa. 



Guinea Pig No. 4. The animal was in a dying condition, 



