an. 



.bl 



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



Craniata. 



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

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



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

 602 



