THE STRUCTURE OF FREE-MARTIN GONADS 77 



and uterus quite rudimentary. Vas deferens (lower half) and sem.- 

 inal vesicles present. Gonads rudimentary and lying in ovarian- 

 position. No spermatic cord. Owing to the atypical organizar 

 tion of the sex-cord region in this case, it will be considered, 

 separately at the end of the discussion of the other three cases-. 



The general topography of the gonads. These four gonads are 

 very small, oval structures (fig. 5). For comparative sizes and 

 other data, consult tables 1, 2, and 3. They are in reality 

 rudimentary testes, which have failed to descend, and thus 

 retain their embryonic position, i.e., the position normal for 

 ovaries. Like the gonads having a low degree of transformation 

 in the male direction, these possess the majority of the parts 

 typical of a testis. Entering the anterior end and projecting 

 nearly to the posterior end of the reproductive gland in each 

 case, is the rete. It forms an eccentrically placed core, about 

 which are the sexual cords and connective-tissue stroma contain- 

 ing interstitial cells. Surrounding the entire gonad is a capsule 

 of connective-tissue fibers, the tunica albuginea. The anterior 

 end may be further modified by the presence of a well-developed 

 vascular plexus (cases 42 and 66) and of a few very definite 

 epididymal tubules (cases 42 and H-42) . 



The tujiica albuginea and tunica vasculosa. Without excep- 

 tion, the free-martin gonad is enclosed by a capsule of connec- 

 tive-tissue fibers, but the relative thickness of the capsule and 

 the compactness of its fibers vary in the different groups of cases. 

 In the specimens under consideration, the fibers are coarse, 

 compactly arranged in the outer layer, and run parallel with each 

 other as they encircle the gonad (fig. 5) . If these fibers are com.- 

 pared with corresponding fibers in the tunica albuginea of a 

 mature foetal testis, the latter are seen to be more closely packed 

 together and the individual fibers finer. The capsule of the 

 mature foetal testis is thirteen times thicker than that of the 

 free-martin gonads of this group. 



In some of the free-martin gonads of this group, the inner 

 portion of the connective-tissue capsule is characterized by a 

 loose arrangement of the fibers. In cases 66 and 42 a few blood- 

 vessels make their appearance in this layer, forming a primor- 



