26 THE VASCULAR SYSTEM OF THE FROG. 
1. The right renal portal vein: the dorsal branch of 
the right femoral vein: it runs forward along 
the outer side of the kidney and ends in numerous 
branches in its substance. It receives the follow- 
ing branches :— 
i. The right sciatic vein: from the muscles and 
skin of the back of the thigh: it joins the 
renal portal vein close to its commencement, 
and before it reaches the kidney. 
ii, The right dorso-lumbar veins: small veins 
from the dorsal wall of the body, and (in the 
female) from the oviduct: they join the 
renal portal vein opposite the kidney. 
2. The left renal portal vein: its course and branches 
correspond to those of the right vein. 
b. The hepatic portal system. 
Formed partly by the anterior abdominal vein, which brings 
to the liver blood from the hind-limbs ; and partly by veins 
returning blood from the alimentary canal. 
1. The anterior abdominal vein: a median vein 
formed by the union of the two pelvic veins—the 
ventral branches of the femoral veins. It runs 
up the middle line of the ventral body-wall to 
the level of the liver, where it leaves the body- 
wall and divides into right and left branches, 
which enter the right and left lobes of the liver 
respectively. During its course it receives the 
following veins :— 
i, Vesical veins: from the bladder. 
ii, Parietal veins: from the ventral body-wall. 
iii, A cardiac vein: from a network of vessels on 
the truncus arteriosus. 
2. The hepatic portal vein: a wide vein which runs 
in the mesentery and joins the anterior abdo- 
minal vein at its point of division into right 
and left branches ; giving off, before doing so, 
a branch to the left lobe of the liver. It 
carries to the liver the blood from the walls of 
