212 



UROGENITAL SYSTEM 



upper limb. The middle limb, somewhat U-shaped, bulges into the concavity of 

 Bowman's capsule (Fig. 206 B). By differentiation the lower portion of the 

 lower limb becomes Bowman's capsule, ingrowing arteries forming the glomerulus. 

 The upper part of the same limb by enlargement, elongation and coiling becomes 



Fig. 208. — Several stages in the development of the uriniferous tubules and glomeruli of the human 

 metanephros (reconstructions by Huber). 



the proximal convoluted tubule. The neighboring portion of the middle limb 

 forms the primitive loop (of Stoerck) ; the base of the middle limb gives rise to the 

 connecting piece, and the rest of it, with the upper limb of the S, forms the distal 

 convoluted tubule (intermediate piece of Felix). The primitive loop of Stoerck 



