76 BENJAMIN H. WILLIER 



eccentrically placed mass of rete tubules in such a manner as to 

 enclose it. 



Obviously, from the above embryological account, the rete 

 mass is primarily located at the hilus of the free-martin gonad, 

 and since this gonad is transforming into a testis it is to be 

 expected that the rete mass should come to lie in the center of a 

 round gland. However, in gonads having a low degree of 

 transformation in the male direction, as in cases H-40 and H-36, 

 the rete region lies at the hilus. This is due to the small size of 

 the sex-cord region. In other words, the sex-cord region in these 

 cases has not grown enough to surround the rete region. 



B. Gonads exhibiting a medium degree of transformation 



The characteristics of the gonads in this group are: the unde- 

 scended position which they occupy; the contorted tubules of 

 the epididymis are few or entirely absent (as in H-18); the large 

 size and high degree of organization of the sex-cord region; and 

 the establishment of connections between the rete and the sexual 

 cords, and between the rete and the epididymis. 



The histories of the four specimens belonging to this category 

 are as follows: 



Case 66. Born co-twin with a normal male calf. Age five 

 days when slaughtered (youngest post-natal free-martin gonad 

 obtained). In place of the uterus were fine ducts; very minute 

 gonads in ovarian position. 



Case 42. Born co-twin with normal male. Killed twenty-one 

 days after birth. Uterus reduced in size, vagina short and end- 

 ing blindly. Gubernaculum absent; gonads in ovarian position. 



Case H-18 (fig. 5). . Born co-twin to normal bull. Killed 

 October 14, 1913, aged thirty-one days. External genitalia 

 typically female. Vagina and uterus quite rudimentary. Sem- 

 inal vesicles and parts of Wolffian ducts (solid cords) present. 

 Data incomplete on position of the gonads, but they were prob- 

 ably in the ovarian position. No spermatic cord. 



Case H-42. Born co-twin with a normal bull. Aged about 

 eighteen months. External genitalia typically female. Vagina 



