1922.) ** Renal Portal”? System. 12] 
chloride compared with the urine which is secreted when 
the venous supply is eliminated (the contention being that the 
venous supply enables the tubules to absorb more actively). 
The results just recorded, on the contrary, prove that a nate 
venous supply than usual adds chloride to the urine. 
The Interpretation of the Preceding Results 
Since it appears to be still a matter of dispute as to 
whether quantity of urine depends on the rate of flow or on 
the pressure of the blood or other perfusing fluid, and since I 
fact that the composition of the urine depends, other things 
equal, solely on the pressure of the blood supply, and since also 
the acceptance of the truth in these matters is all important not 
only for my explanation of the results described in this Part but 
for the appreciation of the arguments to be advanced in the 
next Part (Part IV) I have found it necessary, even in this 
Abstract of my Memoir, to quote the experiments described in 
Appendix G in full. The results of these experiments make it 
quite clear and beyond dispute (1) that quantity of urine is, 
is ss aera other se mar on shin pressure of ibe perfus- 
ing blood or fluid— the greater the pressure the less the percent- 
age of nitrogen and the greater the percentages of chloride and 
water, and vice versa. Thus quantity of urine is. other things 
equal, dependent on rate of blood flow and not on blood pressure, 
and quality of urine is, other things equal, dependent on blood 
pressure, and there is every reason to believe that all other 
glandular secretions conform to these rules (see Part IV). 
king these truths as granted, the explanation of the 
results of the preceding experiments is quite simple and 
cones Gane with that of all other results described in this 
Memoi n_ these recedin experiments, it has first to be 
rec ognined that the “normal” kidney retaining its venous 
supply not normal in the sense that its venous supply 
senemailia closely that of a kidney in a frog which has neither 
of its renal afferent veins ligatured. On the contrary, owing 
to the ligature of the renal afferent vein of the ligatured kidney. 
the venous blood from the legs has to return to the heart via 
abdominal) instead of three, and the remaining renal afferent 
vein Laeger bese apprec reciably more blood than usual. 
blood pressure in the renal afferent vein of the 
“ normal ” idney t is responsible for all three results rec corded in 
the preceding experiments, viz. the greater quantity of urine 
