RAN A. 343 



receives blood from the kidneys by renals and from the 

 genital organs. It then passes forwards through the liver, 

 which it drains by paired hepatics, and discharges itself 

 into the sinus venosus. 



. The two lungs have separate pulmonary veins which fall 

 together into the left auricle of the heart. 



In the frog there are no paired cardinal veins"^' as in the 

 skate, their function being executed by the unpaired post- 

 caval. On the other hand, the presence of a renal-portal 

 system is a feature of both types. 



Fig. 241. — Ventral View of the Female Urogenital 

 Organs of a Frog. {Ad nat.) 



Internal Opening of 

 Oviduct. 



Oviduct, 



Corpus 



Adiposum. _ 



Ii 



Ovary. 

 Adrenal. 



" Uterine " Portion ^ 



of Oviduct. \T^B»-/ 



Aperture of Ureter, ^y \^R^-^ Ureter. 



Aperture of Oviduct. / ^ ' Cloaca. 



The cloaca is slit open to show openings of ureters and oviducts. 



The kidneys are long, red bodies lying in the dorsal 



wall of the abdominal cavity. Each has a thin, yellow, 



u nit 1 (adrenal body on its ventral face. A ureter 



leaves the outer posterior border of each kidney 



to open separately into the cloaca just dorsal to the opening 



of the urinary bladder already noticed. 



In the male the testes are oval, light-yellow bodies lying 

 ventral to the anterior part of the kidneys and attached to them 

 by peritoneum. A number of fine tubules, the vasa effer- 

 entia, pass from the testes into the kidney, through which they 

 eventually communicate with the ureters. These, therefore, 



* They are present in the Urodela. 



