EXPERIMENTAL PRODUCTION OF HYPOTYPICAL OVARIES. 97 



of connective tissue atresia, especially the later stages are well 

 represented. The uterus shows a predeciduomatous cell layer 

 with mitoses in the mucosa. The gland fundi with high cylin- 

 drical cells. The mammary gland consists of acini with relatively 

 high, well-staining epithelium, but without mitoses, and with 

 rather cellular connective tissue between the acini. We have 

 here to deal with normal sexual organs in an animal at a period 

 about five days after ovulation. 



Guinea Pig No. 12. Weight Oct. 18, 263 grams. Weight 

 Nov. n, 352 grams. In the left horn of the uterus two preg- 

 nancies were found. Ovaries: Good corpora lutea; their central 

 cavities are filled with connective tissue; good follicles of all 

 sizes. Follicles with granulosa degeneration; good mature fol- 

 licles; various stages of connective tissue atresia. Uterus is 

 that of pregnancy. In addition to these three guinea pigs, 

 two other guinea pigs obtained from Iowa (ia and 16) were 

 examined as controls at the beginning of the experiment. 



Guinea Pig No. ia. Weight Oct. 19, 378 grams. Ovaries: 

 Good corpora lutea; the central cavity is almost completely 

 filled by connective tissue, but a small remnant is still left 

 unorganized. Good small and medium and almost large follicles. 

 Some follicles in the last stages of connective tissue atresia. 

 Uterus well developed with a predeciduomatous cell layer in 

 mucosa. Fundi of glands with high cylindrical cells. Mammary 

 gland: Acini with good cuboidal epithelium and a few mitoses; 

 cellular stroma. We have here to deal w r ith normal sexual 

 organs in an animal about five to six days after ovulation. 



Guinea Pig No. ib. Weight Oct. 19, 271 grams. Ovaries: 

 Good follicles of all sizes, including large and mature follicles. 

 Much hyperemia around the mature follicles, capillaries in theca 

 interna of these follicles much enlarged. Some follicles in various 

 stages of connective tissue atresia, but relatively few follicles 

 in the last stage of connective tissue atresia. No sign of new 

 or degenerating corpora lutea. The uterus showed high cylin- 

 drical surface epithelium; gland ducts with high epithelium; 

 gland fundi with lower epithelium. The mucosa is hyperemic 

 and succulent and papillomatous. A few mitoses in surface 

 epihelium and at the opening of the glands. Mammary gland 



