571 



Crooxiax Lecture : A New Conception of the Glomerular 



Function. 



By T. G. Beodie, M.D., F.E.S., Professor of Physiology in the University 



of Toronto. 



(Lecture delivered June 15, 1911, — MS. received December 9, 1912.) 



[Plate 26.] 



I have chosen as the subject of this lecture the physiology of the kidney, 

 and more particularly the mode of action of one part of it, namely the 

 glomerulus. In 1906, at the meeting of the British Medical Association in 

 Toronto, I brought forward a new conception of the action of this very 

 characteristic portion of the renal apparatus, and since that time have been 

 accumulating a considerable mass of evidence by the light of which my theory 

 can be criticised. 



Very shortly after the discovery of the main details of the structure of the 

 kidney, Ludwig, basing his ideas upon the then known structure, put forward 

 his well-known theory that the glomerulus was a filter, and since that time 

 all discussions upon renal activity have centred round this theory because it 

 offered an explanation of the mode of action of one part of the mechanism 

 upon hydrodynamic principles. The necessary corollary following from this 

 assumption of filtration is that a considerable degree of absorption must be 

 effected as the dilute filtrate travels down the tubule, and how excessively 

 great this must be was first pointed out by Heidenhain. 



If we consider the results obtained by the earlier workers upon the kidney, 

 very many of them appear sufficiently well explained by the Ludwig theory, 

 but as in the course of years a far stricter examination of the theory was 

 attempted, several observations were made which proved very difficult to 

 explain, and in many cases it was necessaiy to make such extensive and often 

 contradictory assumptions that it became increasingly difficult to accept the 

 theory. Of recent years evidence has been obtained in many directions 

 which in my opinion conclusively proves that the glomerulus is not a 

 filtering surface. It is not my object to-day to discuss this point in any 

 detail. I may refer to my lecture delivered before the Harvey Society in 

 New York in December, 1909, where a short summary of the facts for and 

 against filtration is given, or to the excellent paper by Magnus, in the 

 ' Handbuch der Biochemie,' where it is discussed in eo:temo. It will be 

 sufficient for my present purpose if I indicate the chief reasons which led me 



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