38 APPLIED PHYSIOLOGY 



fasting, and comparing it with that in the blood of the 

 hepatic vein. Needless to say, this experiment has been 

 tried many times, but observers are not agreed as 

 to the result. The fact appears to be that a degree of 

 difference which would be quite sufficient to establish 

 the truth of the classical view once and for all is yet 

 within the limits of experimental error in the estimation 

 of sugar. Apart from this, however, it would seem 

 unlikely that all the sugar entering the body could be 

 transported in a protein form; for, after all, though 

 most proteins do contain a carbohydrate radicle, yet the 

 amount of this in the ordinary blood-proteins is but 

 small. At present, however, the dispute is still un- \ 

 settled, though the vast mass of physiological opinion 

 is in favour of the classical view. The point is of im- 

 portance to the clinician in the pathology of diabetes, 

 for, according to Pavy, one factor in the production of 

 that disease is a failure of the liver to perform its 

 normal function of converting sugar into other forms, 

 with the result that it passes unchanged into the blood 

 and leaks out through the kidneys.* According to the 

 prevailing view, on the other hand, diabetes is due to 

 a failure on the part of the cells to utilize sugar, which 

 failure, in its turn, is consequent upon defective power 

 of glycogen formation ; for it is only as glycogen that 

 carbohydrates can be utilized, or, as von Noorden puts 

 it, glycogen is the natural fuel of the cells, not glucose. 

 In the reason for this failure of glycogen formation the 

 riddle of diabetes resides. 



* It should be remembered that in health the whole volume 

 of the blood contains less than ^ ounce of sugar hi solution. 



