24 LEO LOEB. 



two corpora lutea in left, one corpus luteum in right ovary. 

 Examination ten days later showed the presence of one pregnancy 

 in each horn. The ovaries contained good small and almost 

 medium-sized follicles. There was present one small to medium- 

 sized follicle with a partial, slowly progressing degeneration of the 

 granulosa; there are, furthermore, follicles in various stages of 

 connective tissue atresia. In the right ovary there are two young 

 corpora lutea in which one half to two thirds of the central cavity 

 had been filled by connective tissue. Ovulation had taken place 

 four to five days previously (eleven to twelve days after the 

 previous copulation). The uterus showed low cuboidal epithe- 

 lium with vacuoles and some mitoses, small glands without 

 mitoses. The connective tissue is fibrillar and contains small 

 nuclei; no mitoses are present in the connective tissue. Cyclic 

 changes in the uterus are absent; the uterus is characteristic of a 

 pregnant guinea-pig. 



(4) No. 781. Seven days, five and one half hours, extirpate 

 two corpora lutea in right, one corpus luteum in left ovary. 

 Examination eleven days later; two pregnancies in right horn 

 of uterus; no pregnancy in left horn. In both ovaries there were 

 new corpora lutea in which the central cavity had been filled with 

 connective tissue. The condition of the ovaries indicated a new 

 ovulation about four to five days previously (thirteen to fourteen 

 days after copulation). The uterus shows the same condition 

 as in the former animals (Nos. 748, 752, 780). The epithelium 

 was low, the surface epithelium contained mitoses. The con- 

 nective tissue did not contain a cell-layer and was without 

 mitoses. 



(5) No. 786. Seven days, five hours after copulation, ex- 

 tirpate one corpus luteum in each ovary. Nine days later 

 examination showed one pregnancy in the right horn of the uterus. 

 In both ovaries there were young corpora lutea in which con- 

 nective tissue began to grow in the periphery of the central 

 cavity; there were small good follicles and follicles in early- 

 medium and late connective tissue atresia. Ovulation had taken 

 place approximately two days previously (fourteen days after 

 copulation). The uterus showed the same structure as in the 

 previous specimens; but the surface epithelium did not contain 



