THE UROGENITAL SYSTEM. 



Ill 



is formed in the embryo later than the Wolffian duct. In 

 fishes the Miillerian is derived from the Wolffian duct. They 



myotome 



Wolffian duct 

 Miillerian duct 

 Wolffian ridge 

 Somatopleure 



neural canal 



.sclerotome 



notochord 

 intermediate cell mass 

 visceral mesoblast 



—gut. 



Fig. 85. — A transverse section to show the manner in which the Wolffian and 

 Miillerian Ducts arite, and their position in the Wolffian Ridge. (After 

 Kollmann.) 



right Mullerian duct. 

 Wolffian duct. 



inguinal fold 



bladder-u 



uro-gen. sinus 

 genit. tuber. 



rectum 

 left Mul. duct. 



genit. cord 



Fig. 86.— Diagram of the Genital Ducts at -the commencement of the 3rd month of 

 foetal life. Lateral view. 



open in that part of the cloaca which forms the wfek of the 

 bladder, between the openings of the Wolffian ducts (Fig. 86). 

 They are developed in the male as well as the female embryo. 



