ACTION OF SEX HORMONES IN FOETAL LIFE 409 



6, 7, and 8. Cases 32, 23, and 36. 16.75, 17.5, and 17.5 

 cm. respectively may be mentioned together (figs. 17, 18, and 

 19). The drawings of these three specimens show essentially 

 the same anatomical characteristics as the preceding stage; the 

 gonads are very small in all, but somewhat larger in 32 (fig. 17) 

 than in the others. They all exhibit gubernacula and the 

 ducts resemble the male ducts much more than the female; the 

 urinogenital sinus is intermediate in length between the female 

 (fig. 9) and the male (fig. 10). 



Histories. Case 32. Figure 17. Bovine twins. Male 18 

 cm., female 16.75 cm. Collected January 1, 1916. Both ma- 

 ternal ovaries present; corpus luteum in each. The uterus was 

 injured and the single chorion cut in two; there was an arterial 

 connection between the halves, and cotyledons continued 

 through. 



Case 23. Figure 18. Bovine twins. Male 18 cm., female 

 17.5 cm. Collected October 29, 1915. Only one maternal 

 ovary present, containing single corpus luteum. The chorion 

 was single; broad connection between the two halves; cotyle- 

 dons in connecting part. 



Case 36. Figure 19. Bovine twins. Male 18 cm., female 

 17.5 cm. Collected January 21, 1916. Both maternal ovaries 

 present with a single corpus luteum in each. The chorion w^as 

 single with broad connection occupied by cotyledons between 

 the two halves. Arterial anastomosis present; veins interdigi- 

 tate, and may communicate. 



Summary of the preceding cases. The gross anatomical find- 

 ings for the stages 7.5 to 17.5 cm. thus show that the effects 

 (either direct or indirect) of the male hormones on the reproduc- 

 tive system of the female are (1) to inhibit the growth of the 

 gonad, (2) to cause the formation of typical gubernacula in place 

 of the round ligament, (3) to favor the development of the 

 Wolffian ducts and inhibit the development of the Miillerian 

 ducts. The urinogenital sinus is intermediate between the male 

 and female condition and the phallus develops similarly to that 

 of the female; moreover the disposition of the teats is female, 

 differing definitely from that of the male (figs. 4, 12, 25 A) and no 



