18 Macteay Memortat Vouume. 
The veins may be conveniently grouped as follows :— 
A. Caudal vein. 
. Renal portal system. 
Anterior abdominal system. 
. Hepatic portal system and hepatic veins. 
. Derivatives of the anterior cardinal system. 
cl [col es) ek tos) 
Derivatives of the posterior cardinal system, including the inferior vena 
cava. 
G. Brachial veins. 
H. Cutaneous veins. 
We will deal with these in the order indicated. 
A. Caudal vetn (figs. 10 and 16). 
This runs below the dorsal aorta from the posterior end forwards to the level of 
the first hemal arch. Here it passes downwards into the body cavity. As it passes — 
forwards and downwards, it reaches a point at the level of about one-third of the 
length from the anterior end of the kidney (fig. 10,%.). It then divides into two parts, 
one running to the right and the other to the left, of which the right hand branch is 
much larger than the left. 
Into each enters (a) a branch from the posterior two-thirds of the kidney and (b) 
a branch from the anterior third of the kidney which two branches may be regarded 
as vene renales advehentes (fig. 10, v.7.a.). The main vein passes on into the testis 
or ovary, as the case may be, of each side, the right branch being again much larger 
than the left. 
B. Renal portal system (figs. 10, 16, and 19). 
The kidneys are supplied with three series of vex@ renales advehentes in addition 
to those just described. 
(1) Posterior trunk veins (= postertor vene renales advehentes of Gimther). 
On either side of the body the venous blood from the muscle segments behind 
the cloacal region is collected into two veins. One of these lies more superficially 
than the other and passes backwards along the ventro-lateral surface of the body ; 
the other comes from the deeper lying and more laterally placed muscles. 
