EXPERIMENTAL PRODUCTION OF HYPOTYPICAL OVARIES. 93 



latter slow disintegration of granulosa cells takes place and 

 connective tissue grows in. Small follicles in various stages of 

 connective tissue atresia; many follicles in the last stage of 

 atresia, with relative prominence of the theca interna. Rem- 

 nants of old retrogressing corpora lutea: yellowish stained 

 vacuolar cells surrounded by dense hyaline fibrous tissue, tra- 

 versed by thick-walled blood vessels. In addition we find well- 

 preserved small corpora lutea with capillaries and myxoid connec- 

 tive tissue in center. Mitoses are not present in the corpora 

 lutea. The uterus thin, with low cylindrical surface epithelium 

 and small glands. The mucosa is fibrillar. No sign of a cell- 

 layer. 



We must assume that ovulation had taken place at least as 

 early as ten days before examination or even somewhat earlier. 

 The structure of the corpus luteum and the absence of all 

 proliferative changes in the uterine mucosa suggest this conclu- 

 sion. The new corpora lutea remain small as a result of the 

 insufficient food. The follicles develop only to small-medium 

 size and then undergo atresia. Thus hypotypical ovaries are 

 produced. The uterus is thin, atrophic. 



Guinea Pig B. Examined six days after beginning of feeding 

 experiment; had lost approximately 25 per cent, to 27 per cent, 

 of its weight. This animal was found dead; examination several 

 hours after death. 



In the ovaries good-sized follicles with granulosa degeneration ; 

 good small and small-medium follicles; various stages of con- 

 nective tissue atresia. Neither a preserved nor a retrogressing 

 corpus luteum present. The uterus is thin with the usual low 

 cylindrical epithelium of surface and small glands. Some epi- 

 thelial cells at top of papillae show mucoid transformation; 

 fibrillar mucosa. In this case we have to deal with ovaries which 

 are not yet hypotypical, but which apparently undergo some 

 changes tending towards a hypotypical condition; the larger 

 follicles degenerate and the smaller follicles would in all prob- 

 ability fail to develop to their full size. In this animal ovulation 

 had failed to take place throughout a considerable period of time. 



Guinea Pig B\- Examined ten days after beginning of feeding 

 experiment; had lost 27 per cent, of its weight. Ovaries show 



