THE STRUCTURE OF FREE-MARTIN GONADS 87 



the medullary cords of foetal ovaries in cattle. It may be that 

 the germ cells which are present in the sexual cords of the foetal 

 free-martin gonads persist to form follicles, instead of degenerat- 

 ing as in all of the other free-martin gonads examined. (For a 

 further consideration of the fate of these germ cells, the general 

 discussion may be consulted) , 



The rete tubules and connections. The rete region in each 

 free-martin gonad of this group is a distinct cord of tubules, 

 which enters the anterior end and penetrates nearly to the 

 posterior end of the gonad. It retains its primitive relation to 

 the sex-cord region by its eccentric position. In other words, 

 although the sex-cord region is large and moderately well organ- 

 ized, it has not grown sufficiently to entirely surround the rete, 

 ■ so that the rete lies next to the tunica albuginea (fig. 5) as in the 

 gonads exhibiting a low degree of transformation. The struc- 

 ture of the rete tubules resembles the condition described pre- 

 viously for gonads having a low degree of transformation. 



The relationships of the rete tubules to the sexual cords and 

 to the tubules of the epididymis are important indices of the 

 degree of transformation in the male direction. In the normal 

 ovary no branches of the rete establish connections with the 

 medullary cords (fig. 3) but in the normal testis connections 

 between the seminiferous tubules are formed by lateral branches 

 (tubuli recti) of the rete tubules extending to meet the seminif- 

 erous tubules (figs. 4 and 7, st). If such branches of the rete 

 tubules make connections with the sexual cords in the free- 

 martin gonad, it is a further indication of the assumption of 

 male characters. This is exactly what is found in this group of 

 free-martin gonads, although the number of tubuli recti is com- 

 paratively small. Such connections are shown in figure 5, st. 



The relation of the rete tubules to the tubules of the epididy- 

 mis is clearly shown in case 42 (fig. 9, rt, e). This figure illus- 

 trates a transverse section just anterior to the sex-cord region, 

 and shows rete tubules extending to establish connections with 

 a tubule of the vasa efferentia. There are four of these tubules; 

 they are short, closed at both ends, and lined with ciliated 

 epithelial cells, which rest upon a basement membrane enclosed 



