THE RHYTHM OF GOISTADAL FUNCTION 599 



malady cannot fail to center in the apparent proof which it affords of the 

 dependence of the so-called "secretion" changes characteristic of the 

 pregravid endometrium upon a functioning corpus luteum. If a corpus 

 does not exist these secretion changes do not occur. But there may he a 

 remarkable continuance of proliferative phenomena in the endometrium 

 as long as ripe follicles continue to live and hence exert this effect. An 

 analogy with this disorder has been found in the delay of ovulation and 

 prolonged life of ripe follicles which may be found in some animals. 

 Long and I have detected this condition as a rare anomaly in the rat, and 

 it is interesting to note that a continued vaginal epithelial proliferation 

 and desquamation, which, as the diagram of Fig. 1 shows, is the normal 

 pre-ovulatory or follicular effect, continues to be exhibited for a period 

 of from two to six or even twenty days, instead of for thirty hours as is 

 normal. The ovaries exhibit large unruptured follicles. These findings 

 are thus seen to harmonize with our conviction of the distinction to be 

 made in the responses of the uterus to the ovaries during the two phases 

 of ovarian activity which occur respectively before and after the ovula- 

 tory act. 



