1}2 Journal oj the Asiatic Society of Bengal. {N.S., XVIL, 
rally more dilute than normal urine, 
period, when the wound has almost or quite healed and the 
animal is as lively as the control norma] toads. the urine 
exereted is, as we have seen, as plentiful and as strong in 
contents (nitrogen) as that of the normal toads. We must 
therefore conclude that during this convalescent period the 
body has produced an additional quantity of blood sufficient to 
make up for the quantity lying useless in the enlarged anterior 
abdominal and leg veins, and the organs in general will then 
receive as much blood as formerly. But there are two excep- 
tions to this statement, viz. the liver which, until the re-forma- 
tion of the ligatured renal afferent veins, will receive more than 
its normal quantity of blood, and the legs which, for the reason 
already given, will continue to receive less. The toads (not 
enumerated) which died in less than two or three weeks 
subsequent to the operation probably died from the effects of 
the operation ; Toad J, on the other hand, not only survived 
the operation but also the physiological disturbances which 
must ensue in connection with the liver and legs due re- 
spectively, as already stated, to too large a supply of venous 
blood and too small a supply of arterial blood. These disturb- 
ances are evidently quite sufficient by themselves to account 
for the re-formation of the two renal afferent veins, without 
assuming that the renal afferent supply of venous blood to the 
kidneys is in itself essential to the health of the toad. The facts 
already recorded that toads can live three months in an 
apparently healthy condition without a ‘‘ renal portal’’ system 
is sufficient to prove this, and it is therefore practically certain 
that if we could perform the operation of making the two renal 
afferent veins open directly into the post-caval or other large 
vein, thus eliminating the “renal portal’? system and at the 
same time avoiding excess of blood supply to the liver and 
deficient blood supply to the legs,' the toads would after the 
operation resemble normal toads in every respect and the renal 
afferent veins would not re-form so as to re-establish connection 
with the kidneys. Additional proof of this is afforded by the 
discovery in a male specimen of Rana temporaria (the frog OD. 
the renal arteries of which I have already referred to—text- 
figure 4) of practically the condition of things which would exist 
if the supposed operation I have just described were possible in 
practice. 



! In all those abnormal frogs which have been described in which one 
of the kidneys is deprived by nature of a “ renal portal’”’ supply, the renal 
afferent i Agpne rbot directly into the post-caval or into a pre-cava 
i stent posterior cardinal, thus 7. idi excess 
of blood supply to the liver. ; ee ee 

