Follicular Development, Ovular Maturation, Ovulation in Ovarian Tissue 27 



Figure 12 shows a mature follicular ovum that has been stained in toto under 

 a coverslip. The crescentic first polar body has recently been abstricted from 

 the horseshoe-shaped telophase spindle. 



THE RATE OF FORMATION OF MATURING FOLLICLES 



Daily sketches were made of 36 ovarian transplants between the fourth and 

 seventh days following transplantation. The host animals to 30 of these 

 transplants were subjected to PMS and HCG injections, and 6 were untreated 

 controls. The rate of appearance of the follicles growing in treated animals 

 did not differ from the controls. This suggests that the intrinsic pituitary 

 gonadotropin level of the immature castrate male recipient is high enough 

 to stimulate all follicles that are mature enough to respond. 



Sixty-five follicles appeared (diameter 0.25 mm) in the 36 transplants on 

 the fourth, 60 on the fifth, 32 on the sixth, and 28 on the seventh postoperative 

 day. The number of follicles that appear each day diminishes rapidly after 

 the first 2 days, and this cannot be prevented by supplementary gonadotropin 

 injections. These direct observations are in agreement with the theory that 

 the original stimulus for follicular maturation is independent of gonadotropic 

 hormone stimulation. 



In order to compare the performance of transplants with that of ovaries 

 in situ, 25-day-old female rats were injected with gonadotropin on the same 

 schedule that has been outlined above. Serial sections of these normal control 

 ovaries showed that the average number of follicles that "appear" each day 

 is five times that observed in the transplants. Probably the smaller original 

 size of the transplant, plus the massive follicular degeneration that occurs 

 before its new blood supply develops is sufficient to account for this difference. 

 It is not likely that antigenic influences would be manifest so soon after 

 transplantation. 



Plate II 



Fig. 7. A developing follicle from an ovarian transplant 70 hr after injecting the recipient 

 with PMS and 14 hr following the injection of 30 international units of human chorionic 

 gonadotropin. Volume = 90 x 10^ /x^. The opening in the follicle is possibly the 



point of ovulation. ( x 90) 



Fig. 8. An ovum 14 hr following HCG injection, showing the first polar body. 

 Mitosis of a cumulus cell can be seen to the upper right. ( x 370) 



Fig. 9. An ovarian transplant 78 hr following PMS and 22 hr following HCG, 



showing early corpora lutea. The cornea is on the left and the attachment of the iris to 



the graft is shown to the right. ( x 20) 



Fig. 10. An early corpus luteum from Fig. 9, showing a squeezed atretic ovum to the 



right. ( X 20) 



Fig. 1L An ovarian transplant as seen through the dissecting microscope, 14 hr 

 following HCG, and showing, to the left, an ovulated ovum in front of the iris. ( x 20) 



Fig. 12. A follicular rat ovum that has been fixed and stained in toto under a coverslip. 

 The first polar body is being abstricted from the horseshoe-shaped late telophase 



spindle, (x 1300) 



