THE STRUCTURE OF FREE-MARTIN GONADS 107 



E), but it lies eccentric to the greater portion of the sex-cord 

 region. Secondly, as a rule, the distance of the penetration of 

 the core of rete tubules into the gonad varies directly with the 

 increase of maleness (fig. 1, B, C, and D). Thirdly, the lumina 

 of the rete tubules increase in size as the gonad increases in 

 maleness. In the fourth place, the rete tubules establish con- 

 nections with the vasa efferentia and with the seminiferous 

 tubules; only a few such connections are made in the moder- 

 ately transformed gonads, while in the most highly transformed 

 gonads many are made. Obviously, the rete of the free-martin 

 gonad may be transformed into a typical rete testis. 



The connective-tissue capsules exhibit three more or less dis- 

 tinct and progressive stages of development in the male direc- 

 tion. These stages correspond only in a very rough way to the 

 degree of transformation of the gonads, but correspond very 

 closely to the stages passed through in the normal development 

 of the tunica albuginea of the testis. The first stage is charac- 

 terized by a comparatively thin layer of connective-tissue fibers; 

 in the second stage the capsule possesses two layers, the tunica 

 albuginea and the tunica vasculosa, while in the third stage the 

 tunica vasculosa is merged with the tunica albuginea. 



Closely associated with the degree of development of the con- 

 nective-tissue capsule is the distribution of the blood-vessels. 

 In the highly transformed gonads a vascular cord, which is 

 typically like the normal vascular cord of the testis, penetrates 

 into the anterior end to connect with the tunica vasculosa or 

 with the vascular portion of the tunica albuginea. In less trans- 

 formed cases a much less typical vascular cord enters the gonad 

 at a point slightly posterior to the anterior end, from which its 

 blood-vessels are distributed in some specimens to the tunica 

 vasculosa, and in others directly outward to the sex-cord region 

 as in the normal ovary. 



The epididymis also exhibits a graded series of transforma^ 

 tions in the male direction. In the least transformed gonads 

 there are no traces of epididymal tubules; in the moderately 

 transformed gonads there are traces of tubules, while in the most 

 highly transformed gonads the typical epididymal bodies are 

 present. 



