400 



THE DEVELOPMENT OF THE CHICK 



old. The germinal epithelium covers the surface and is continu- 

 ous with the ovigerous strands projecting far into the stroma. 

 The strands are broken up in the stroma into nests of cells; 

 next the germinal epithelium are found characteristic primi- 

 tive ova, but in deeper situations the primitive ova are larger 

 and each is accompanied by a group of epithelial cells, which are 

 distinctly differentiated as granulosa cells of young follicles in 



FIG. 230. Cross-section of the ovary of a fledgling of Numenius ar- 

 cuatus 3-4 days old. The germinal epithelium is below. (After 

 -Hoffmann.) 

 s. c., Sexual cords. 



the deepest. Thus the young follicles arise by separation of 



nests of cells from the ovigerous strands within the stroma' 



*fa nest includes a young ovocyte and a group of epithelial 



s which arrange themselves in a single layer of cuboidal cells 



around the ovocyte. On each side of the free border of the ovary 



the embryonic state persists, and it is not known whether this 



