FIG. 162. Diagrams illustrating the development of the urinogenital organs of 



Craniata. 



A, pronephros and its duct; B, atrophy of pronephros, development of 

 mesonephros ; C, differentiation of Wolffian and Miillerian ducts ; D, develop- 

 ment of metanephros, male type ; E, female type. 

 602 



