REPRODUCTIVE SYSTEM OF FREE-MARTINS 457 



to degenerate. In an 8.3 cm. 9 N7 (fig. 3) and in a 7.3 cm. 9 

 N8, primary follicles are found in the medulla. The inclosed 

 ovum is usually indifferent but may have begun to degenerate. 

 Separating the medullary cords from the outer layer of sex 

 cords, the cords of Pfliiger, is a layer of connective tissue, the 

 primary albuginea. Strands of connective tissue extend out- 

 wards from this layer, toward the periphery of the gland, sepa- 

 rating the cords of Pfliiger from each other and forming the 

 stroma of the cortex. This cortex is narrow. The cords of 

 Pfliiger are still in an early stage of development, the cells not 

 yet being arranged in 'nests' surrounding gromng ova. The 

 germ cells are still in the indifTerent stage. No interstitial cells 

 can be distinguished. The germinal epithelium is a single layer 

 of cuboidal epithehal cells. The cords of Pfliiger have not 

 yet been separated from it by the development of the definitive 

 albuginea. 



The normal ovary has a different shape from that of the testis. 

 The rete, entering near the anterior end, lies close to the mesen- 

 tery which connects the ovary with the Wolffian body. The 

 rete ovarii does not grow far posteriorly at as early a stage as 

 does the rete testis. During the further development of the 

 foetal ovary, the cortex grows more rapidly than the medullary 

 region, extends toward the Wolffian body on each side of the 

 mesentery, and the two sides approximate each other second- 

 arily, making the rete appear to be in the center of a round gland 

 as it is primarily in the testis. 



Fig. 1 Cross section of testis and Wolffian body of 7 cm. d' Bos embryo, 

 NIO, near anterior end, showing rete entering the testis. 1, glomerulus; 2, secre- 

 tory tubule; 3, collecting tubule; 4, Wolffian duct; 5, MiiUerian duct; 6, rete cord, 

 (with lumen); 7, interstitial material; <S, seminiferous tubule; 9, albuginea; 10, 

 superficial epithelium (peritoneum). X 20. 



Fig. 2 Cross section of testis arid Wolffian body at 7 cm. d' Bos embryo, 

 NIO near middle of gonad. Designations as in figure 1. X 20. 



Fig. 3 Cross section of ovary and Wolffian body of 8.3 cm. 9 Bos embryo, 

 N7, near middle of ovary, showing position of rete in 9 as compared with that 

 in cf, figure 2. 1, rete; 2, medullary cords; 3, primary albuginea; 4, cords of 

 Pfliiger; 5, germinal epithelium; 6, Bowman's capsule (Malpighian body); 7, 

 Wolffian tubule; 8, Wolffian duct; 5, Mullerian duct. X 42. 



