WORK 117 



pletely. So far as I am aware Abderhalden, Messner and Windrath 

 (48) are the only workers who have ever offered experimental evidence 

 of a retention of nitrogen without carbohydrate being also present in 

 the diet. As has been already suggested (p. 40) this result is in all 

 probability due to the fact that the necessary carbohydrate was ob- 

 tained from the protein, or the fat, in the diet. Luthje (269) has also 

 clearly demonstrated, in his feeding experiments on rabbits, that the 

 carbohydrate moiety of the diet is of absolute importance in the utiliza- 

 tion of protein. He suggested that some form of amino sugar was 

 first formed. Ross Taylor and Cathcart (394) have shown that, if 

 glycosuria be induced by injections of phloridzin, there is an immedi- 

 ate appearance of creatine in the urine, which only lasts as long as the 

 glycosuria exists, thus agreeing with the previous observations on 

 the close relationship between the output of creatine and carbohydrate 

 metabolism. These observations have been fully confirmed and ex- 

 tended by Krause and Cramer (230), and by Wolf (422). Ross Taylor 

 (393 A ) an d Krause and Cramer (230) have also shown that in diabetes 

 mellitus there is an appearance of creatine in the urine. 



Falta, Grote and Staehelin (124) found that when the metabolism 

 of carbohydrate was interfered with after the removal of the pancreas, 

 there was a very great rise in the breakdown of body protein as 

 evidenced by the increased output of nitrogen. They hold that 

 carbohydrate is essential for the general metabolic processes of the 

 body, and if the animal cannot get it directly, then it obtains it in- 

 directly from the protein ; the sudden increase in the output of nitrogen 

 is thus accounted for. 



Why should carbohydrate be continually produced in these cases of 

 experimental diabetes even to the extent of breaking down protein 

 tissue after all the free sugar has been excreted ? It is hardly probable 

 that it is formed merely to be turned out again a mere disturbance 

 in the normal mode of catabolism. It must be produced as the result 

 of a definite call of the cells for carbohydrate a substance essential 

 to their very existence. Carbohydrate is surely a substance of vital 

 importance from the fact that the last traces of glycogen in hunger 

 disappear but slowly, more especially from the muscles, and that sugar, 

 although it is so readily utilized, is never absent from the blood, even 

 at the end of starvation. It is probably a provision for the proper re- 

 utilization of the products of protein digestion which arise from the 

 autolysis of the tissues during this condition and which are required as 

 foodstuffs by the heart and other essential organs. Falta and Gigon 

 (123) carried out a series of experiments on the utilization of proteins 



