THE URINOGENITAL SYSTEM 397 
sexual and a posterior non-sexual portion. In the latter part of 
the period of incubation the non-sexual portion undergoes absorp- 
tion while the anterior portion becomes converted into the epididy- 
mis. 
The increase of primitive ova in the germinal epithelium and 
their migration into the sexual cords continues until about the four- 
teenth day. In the meantime the stroma has increased notably 
in amount; it constitutes a considerable layer between the cords, 
Fic. 228. — Cross-section through the periphery of the testis of a 
just hatched chick. (After Semon.) The sexual cords have 
acquired a lumen, and the walls of the canals are formed of the 
primitive ova and the cells of the sexual cords, or supporting 
cells. The connective tissue forms septulze, connecting with the 
albuginea; the remains of the germinal epithelium form the serous 
covering of the testis. 
Alb., Albuginea. ce. T., Connective tissue of the septule testis. 
1., Lumen of the sexual cords. pr. O., Primitive ova. - s. C., Sexual 
cord. 
and begins now to form a layer between the germinal epithelium 
and the distal ends of the sexual cords. This layer forms the 
albuginea of the testis, and with its establishment the production 
of the primitive ova from the germinal epithelium ceases, and the 
latter becomes reduced to an endothelial layer (Fig. 228). 
