56 THE NECTURUS 



In the males the anterior end of the mesonephros is 

 utilized to carry away the sex products. It is supplied 

 with vasa efferentia which connect with the tubules of the 

 mesonephros and thus get to the mesonephric duct. The 

 upper and anterior end of the organ is entirely taken over 

 for this purpose, so that the posterior end only, acts as an 

 organ of excretion. 



In the females the Miillerian duct or oviduct serves for 

 the purposes of carrying away the eggs so the mesonephros 

 is no longer used in this way and carries nothing but the 

 products of the organ itself. 



The mesonephroi extend along the body cavity just dor- 

 sal to the oviducts and between them. The ureter is a 

 very delicate tube to be seen at the lateral border of the 

 mesonephroi. It extends posteriorly and opens into the 

 cloaca. Remove the cloaca and trace the ureters to the 

 wall of the cloaca. A tubular urinary bladder is to be 

 found on the ventral side of the cloaca. It is thin and 

 usually empty. 



Drawing 19. Make a drawing showing the parts of the female 

 urogenital system. 



MALE UROGENITAL SYSTEM 



Testes 



The testes are two oblong bodies about 50 mm. in length. 

 They are dorsal to the intestine and fastened to the body 

 wall by the mesorchium. The outlet from the testes the 

 vasa efferentia passes to the mesonephros, where after 

 going through the tubules, it comes to the Wolffian or 

 mesonephric duct and utilizing this, passes to the cloaca. 

 The number of the vasa efferentia should be noted. 



