REPRODUCTIVE SYSTEM OF FREE-MARTINS 461 



epithelial cells which form the duct are not present through its 

 entire length. 



Summary. The gonad of this 7.5 cm. free-martin resembles a 

 reduced testis in the presence of albuginea, thin covering of 

 peritoneum, and absence of cords of Pfitiger, and differs from 

 the ovary in the same respects. It is like the ovary in the posi- 

 tion of the rete. The ducts resembles those of the male in 

 tliat the Wolffian duct is complete and degeneration of the 

 Miillerian duct has commenced. The Wolffian body is like that 

 of normal embryos of the same size. 



2. FREE-MARTIN, 12.5 CM. T26 



The next size of free-martin which was examined microscopi- 

 cally, T26, measured 12.5 cm. This may be compared with the 

 12.75 cm. male T16, and the 14 cm. female N26. 



a. Normal conditions at this stage 



The testis of the male is 4.45 mm. long. The seminiferous 

 tubules are already branched, contorted, and very numerous, but 

 have not yet developed lumina. They are separated by a small 

 amount of interstitial material; most of this material is con- 

 nective tissue, but some of the cells resemble interstitial cells as 

 described by B. M. Allen^ and R. H. Whitehead.- Throughout 

 the seminiferous tubules are found primitive sex cells, some of 

 which have started upon the growth period.^ A very thin layer 

 of peritoneum covers the surface of the testis. Beneath this 

 lies the albuginea which is wide and compact. 



Fig. 4 Cross section of Wolffian body of 7.5 cm. free-martin T19, at point 

 where rete is pushing o.ut to enter anterior end of gonad. 1, rete; 2, Wolffian 

 tubule; 3, Wolffian duct; 4, Miillerian duct; 5, Glomerulus. X 42. 



Fig. 5 Cross section of Wolffian body and gonad of 7.5 cm. free-martin 

 embryo, T19 through middle of gonad. 1, rete; 2, sex cord region; 3, albuginea; 

 4, germinal epithelium; 5, glomerulus; 6, collecting Wolffian tubule; 7, secretory 

 Wolffian tubule; 8, Wolffian duct; 9, rudimentary Miillerian duct. X 42. 



Fig. 6 Cross section through Wolffian body and middle of gonad of 12.5 cm. 

 free-martin, T26. 1, medullary cords; 2, superficial or germinal epithelium; 3, 

 rete; 4, albuginea; 5, degenerating Wolffian tubules; 6, Wolffian tubules; 7, uro- 

 genital fold in which ducts normally lie. X 42. 



