1917.] The Fourth Indian Science Congress. clxxxi 



* 



were perfectly healthy and had much increased in weight (the ratio 

 Weight of kidneys/ Weight of body was much greater in these toads 

 than in normal toads), though the renal arteries had not increased in 

 size. In all three cases however (even in the three-month toad which 



appeared when killed to be in perfect health, eating well, active and shed- 

 ding its skin on the night previous) the liver was in a diseased condition, 

 large cysts having developed in it, which condition was apparently solely 

 due to the large amount of additional venous blood poured into it via the 

 anterior abdominal vein. Had it been possible to divert the blood ex- 

 cluded from the renal afferent veins into the main venous system instead 

 of into the liver capillaries, the three toads would have remained in per- 

 fect health. ■ . _ . . u 

 In 1916 I repeated these experiments and obtained similar results. 



In the case of one toad which lived nearly six weeks, I analysed the urine 

 while the animal was in good health (active and feeding like normal toad) 

 and ascertained that the urine secreted each day was normal in quantity 

 (total nitrogen estimation) as compared with that of normal control toads. 



In 1915 I also ligatured one renal afferent vein in each of tour toads, 

 . one surviving three and a half weeks and another eight weeks after the 

 operation ; the other two I killed after eight weeks and twelve weeks res- 

 pectively. In all cases the kidneys were together slightly larger tba&m 

 normal toads and were equal in size to each other, the kidney with the 

 ligatured vein sometimes being larger than the other. 



In 1915 and 1016 I cut out a piece of the anterior abdominal vein in 

 a number of toads and found that they either died, or, after a certain 

 number of days, re-formed a new abdominal vein ; in no case aid the toad 

 assume a healthy appearance and remain devoid of an anterior abdominal 



The conclusions I drew from those results were that the arterial 

 supply of the kidney is the only essential one, the kidney not making use 

 of the venous blood supplied by the renal afferent or other veins. 



vein. 



num 



perfusion and other experiments on the frog (E. ttgrina) kidney. The 

 most important experiment I performed (repeated twelve times) was to 

 anaesthetize a frog with ether, remove all the brain except the cerebellum 

 (thus preserving the respiratory centres), ligature the renal afferent ve n 

 (which was cut behind the ligature) and pelvic vein of one side and run in 

 normal saline (with or without a trace of urine) through a « aimul » ""?£ 

 ted into the co 'liaco-mesenteric artery and connected with a P e ™ on 

 bottle. The frog continued to breathe well for several hours, censur- 

 ing the oxygenation of the saline solution traversing he renal arteries and 

 the rest of the body. The ligature of the pelvic and the cutting , of the emd 

 afferent of the same side posterior to the ligature ensure t hat J^e pressures 

 in the two iliac arteries are approximately equal and there ore ^ that he 

 pressure in the unligatured renal afferent bears mud, the san e relation to 

 the pressure in the renal arteries as exists in life. The ureteis e,e care- 

 full/ dissected out and inserted each into a glass coUectmg : *««^Jne 

 results of these experiments were that during the ^ me . J^^'**^ 

 renal afferent vein remains empty and the pressure in .the .kidney of that 

 side (the « arterial " kidney) is therefore less than the pressui in the 

 other kidnfiv the secretion of the arterial kidney is less, bu when tne 

 ngatoredt/a'l HeZTvein becomes distended with the perfusion solution 



from the renal arteries, then the secretins of the J^JSwS^iJiJS 

 duced at an equal rate, though the urine of the arterial k.dney » more 



"%&j^!tt£tt -ins carrying blood tothe kidney 



fluid used), was found to he as strong as normal urine 



In another series of experiments I connected the l.ac a. terywitn t e 

 renal afferent vein of the same side by means of a glass L tube ana so 



