In order to make out the femoral and the sciatic veins, turn the Plat ana 

 over and remove the skin from the back of the leg. The femoral vein may 

 then be seen lying on the surface of the leg, between two of the muscles. 

 By carefully separating these muscles the whole of the femoral vein may 

 be exposed. Deeper down in the muscles of the leg lies the sciatic vein, 

 and, between the sciatic and the femoral veins, the internal iliac artery may 

 be seen running alongside of the sciatic nerve. 



Trace the femoral and the sciatic veins forward, and note that they join 

 together at the point where they meet the pelvic veins and then run forward 

 to the kidney as the renal portal vein on each side. 



Turn the Platana over again on to its back and note the renal portal 

 vein from the ventral side. Joining the renal portal vein is a large vein 

 formed of two branches. The one branch arises in the abdominal wall, 

 while the other passes along the base of the leg and joins the abdominal 

 vein. On each side three dorso-lumbar veins join the renal portal vein. 



Fig-. 6.— Venous System of Xenopus and Rana. 



[In the Frog the abdominal vein is also formed by the union of the two 

 pelvic veins. The pelvic veins, however, lie more superficially than in the 

 Platana. The femoral vein which passes along the front of the thigh divides 

 into two branches, the one branch forming the pelvic vein, the other, joined by 

 the sciatic vein from the muscles and shin of the bach of the thigh, forming the 

 renal portal vein extending along the outer side of the hidney. The dorso-lumbar 

 vein from the dorsal wall of the body joins the renal portal vein.'] 



Make a drawing showing the above parts. 



16 



