32 



Development and Shape of Urinifcrous Tubules 



B 



Fig. 5. A series of models A to F, showing successive stages in the devel- 

 opment of uriniferous tubules in rabbit embryos. X 160. A, E, and F. from 

 rabbit embryo (No. 2) of 14 mm. length; B, C, and D from rabbit embryo 

 (No. 3) of 18 mm. length. A and B show each a renal vesicle and a part of a 

 collecting tubule with prominent ampulla; C and D early and late S-shaped 

 tubule. 



