1922. ] “ Renal Portal ”’ System. 107 
where the latter enters the distal portions of the former for 
the exit of the arterial blood ; and (2) that the venous bloo 
takes no part in urine secretion under normal conditions. It 
is obviously important to check the second conclusion by 
experiments on the living animal, and during the years 1915- 18 
inclusive, I carried out a large number of experiments which 
consisted of ligaturing both or one only of the two renal afierent- 
veins in specimens of an Indian toad—Bufo stomaticus (Liitken)! 
—common in the United Provinces (India) and of observing the 
effects (especially on the composition of the urine when compared 
with that of the urine of normal control toads) produced in those 
animals which survived the operation. I may add that I 
selected toads in preference to frogs for these experiments 

es a 3(x 2). The regenerated renal afferent veins of the 
Toad J the ventral aspect. RRAV, right renal afferent vein: 
LRAV, py eka afferent vein, The epee veins differed from 
normal renal afferent veins in being plastered, speak, against the 
dorsal peritoneum—they did not stretch pes Mie body-cavity like 
normal veins. 
because the former can be kept under relatively dry conditions 
een occasional moistening of the belly skin being alone neces- 
sary) and hence sepsis of the wounds is far less liable to occur. 
The mina of Both Renal Afferent Veins in Bufo stomaticus. 
nine toads, which I will designate A, B, C, D, E, F,G, H, 
and i I r ligatared (from the dorsal surface) both renal afferent 
veins ® (each vein being li — in two places and cut 
1 Dr. fist Annandale informs me that this i is the correct naming of the 
B. Ander. of the ‘‘ Fauna of British In — 
21 nye not ligature the dorso-lumbar ns—an omission of no conse 
quence in view of their small size. The canal afferent veins were expose 



