88 Journal of the Asiatic Society of Bengal. [N.S., XVIII, 
injected via the renal afferent vein or via the renal arteries, 
the result is that the dye is always to be found in the sinusoids 
of the intertubular plexus. But it is evident that if we have 
in the “portal” kidney two distinct, though mechanically 
intermingled, systems of sinusoidal channels—the fine inter- 
tubular plexus conveying arterial blood and the coarse renal 
venous meshwork (“ renal portal” system) conveying venous 
blood entirely separate from each other save for the communi- 
cations! by means of which the intertubular plexus pours its 
arterial blood into the renal venous meshwork on its way to 
the renal efferent veins, then it is all essential that in dye-injec- 
tion or perfusion experiments we should maintain the same 
relative fluid pressures in the two systems of channels as exist in 
consider the results of experiments in which dye was only 
injected through one vessel ata time.? No previous dye injec- 
were made, carmine by the arteries and Berlin blue by the renal 
portal veins. One gelatine double injection was also made, 

: 1 ¢ Die Batrachiernieren. . . . bei welchen der Ubergang der Arterien 
in Venen nicht durch successive Gréssenabnahme der Arterie vorbereitet 
wird, sondern plétzlich feinste Arterien in dicke Venenwurzeln einmiin- 
den.” (Hyrtl, 26, p. 175. 
r le, Bainbridge, Collins and nzi ssivel 
perfused 1/10,000 mercuric chiveide, saline an “ on ls fan. ookian 
of ammonium sulphide through the renal afferent vein alone under 10 
cms. pressure, and mercuric sulphide was actually found in some of the 
tsb (‘* the glomeruli Temained free from it in the vast majority of 
results with indigo-carmine saline perfusion at 12 ems. pressure, but not 
at 10 cms. or 7:5 ems, pressure. 


