94 Journal of the Asiatic Society of Bengal. [N.S., XVIII. 
channels (text-figure 1.B). These results thus afford ocular 
demonstration of the fact that two separate and distinct sys- 
tems of vessels traverse the substance of the ‘‘ portal” kidney 
—-one which is normally filled with (arterial) fluid from the 
renal arteries and one which is normally filled with (venous) 
fluid from the renal afferent vein. When dye is present in the 
system containing arterial fluid (the intertubular plexus— 
homologous with that of non-portal kidneys), the dye appears 
in the urine; when dye is present in the system containing 
venous fluid (the renal venous meshwork) the dye is not 
excreted into the urine. This is but one of the many proofs 
which can and will be adduced to show that the venous supply 
of the kidney is not associated in any way with kidney 
excretion. 
Another result of these dye-injection experiments was to 
confirm the observation made by Hyrtl (26), that in the frog’s 
channels, the blood in which therefore does not traverse the 
into contact with the kidney substance. This again is proof 
that the association of the renal afferent vein with the kidney 
must be of very little importance—if the kidney (which has a 
larger arterial supply, relative to its bulk, than any other organ 
in the body) needed venous blood, it is not likely that it would 
be “content” with the aid of a few mic roscopic venous sinusoids, 
but, like the liver, would tequire at least the whole vein. The 
colour, although one is supplied with bright red arterial blood 
alone and the other with dark blue ! venous blood three times 
the volume of the arterial. 2 
Variations in the Composition of the Fluid traversing the Renal 
enous Meshwork have, apart from certain E cceptions to be 
stated, no Effect on the Composition or Quantity of 
the Urine, provided that correct Relative 
ows be maintained. 
Though it has been demonstrated in the previous Section 
that, with correct relative flow, the fluid in the renal afferent 
Not scarlet or ev . hny’s 
: os agra and 15 (17) en purple, as one might suppose from Cushny 
, is 
same fact is observed when in a double perfusion experiment 
