434 DISCOVERY REPORTS 



to the renculi (Figs. 31, 32). The two major branches lie in the same horizontal plane and 

 run posteriorly in the central connective tissue core. The third branch is small and is 

 given off by the distal of the two major branches. It takes a forward direction and 

 supplies the part of the kidney anterior to the point of entrance of the blood vessels. The 

 venous system within the kidney has a twofold arrangement (Fig. 31). In general it may 



Fig- 32. 



A. Main arteries and veins of the kidney (right) of a Fin whale foetus 1-79 m. in length, after injection 

 with carmine. 



B. Main arteries and veins of the kidney (left) of a Fin whale foetus 3-1 m. in length, after injection with 

 carmine. 



be said that there are two main veins in the central core accompanying the arteries on 

 either side of the main urinary duct. There are usually one or more veins draining the 

 apical region. These form a central venous system for the organ and they are fed by 

 lesser veins from all the groups of renculi bordering upon them and upon the central 

 core. The more superficially placed renculi are drained by veins entering the peripheral 

 network of the organ. This network spreads over the whole surface of the kidney within 



