458 



COMPARATIVE ANATOMY 



JT 



FIG. 344. KIDNEY or Discoglossus pictus. From the ventral surface, showing 



the nephrostomes (St). (After J. W. Spengel.) 

 Ur, uriiiogenital duct, enlarging at Ur l to form a seminal vesicle. 



Proteus), 1 but it usually becomes swollen distally and is often 

 bilobed : in Alytes and Bombinator it forms a double sac. 



1 In Amphiuma, it is relatively very long. In the Gymnophiona, the bladder 

 presents certain peculiar secondary modifications. 



