THE CARBOHYDRATES. 277 



suppose that the metabolism of muscle-tissue is here principally 

 at fault, and that the tissue has lost the power of decomposing 

 the sugar which reaches it from the liver. As a consequence, 

 increased destruction of muscle-tissue occurs, as the inability on 

 the part of these structures to decompose sugar amounts to the 

 same as though no sugar were present at all. The body therefore 

 liberates the carbohydrate groups of its albumins to supply the 

 apparent deficit, and thus further increases the hypergluchsemia 

 and the resulting glucosuria. We accordingly find that even 

 though the carbohydrates have been withdrawn from the food 

 sugar still appears in the urine. The increased destruction of the 

 tissue albumins is in such cases sufficiently apparent from the pro- 

 gressive loss of flesh which is so constantly observed. Of the causes 

 which are operative in bringing about the muscular insufficiency as 

 regards the decomposition of sugar, we know but little. That cer- 

 tain nervous influences may here be at work is probable, and we 

 know, as a matter of fact, that injury to a certain region in the floor 

 of the fourth ventricle is invariably followed by the appearance of 

 glucose in the urine. But, on the other hand, we may also imagine 

 that the normal decomposition of the sugar is prevented owing to the 

 absence of some such ferment as the glucolytic ferment of Lepine, 

 and, as has been pointed out, this ferment is in all likelihood formed 

 in the pancreas. In support of this view is the fact that after 

 extirpation of the pancreas death invariably results with symptoms 

 which are practically identical with those seen in the gravest types 

 of diabetes. Ligation of the duct does not produce this effect ; 

 and it is noteworthy, moreover, that the glucosuria disappears when 

 pieces of the pancreas are transplanted under the skin or when 

 fresh raw pancreas is given with the food. Within the past ten 

 years it has been found that in a not inconsiderable number of 

 cases of diabetes degenerative lesions can be demonstrated in the 

 pancreas, and there can be no doubt at the present time that a 

 certain percentage of cases are directly referable to such origin. 

 In the milder forms, on the other hand, an insufficiency on the 

 part of the muscle-tissue manifestly does not exist, as it is possible 

 to prevent the occurrence of glucosuria, temporarily at least, if the 

 demand for sugar is increased by abundant muscular exercise. 

 That a hepatogenic diabetes finally may coexist with a myogenic 

 form, cannot be doubted. 



This is, however, not the place to enter into a detailed account of 

 the mechanism by which glucosuria is produced, and for further 

 information, and for a consideration of the various pathological con- 

 ditions under which sugar may be found in the urine, the reader is 

 referred to other works. 



The amount of sugar which may be present in the urine under 

 pathological conditions is exceedingly variable. On the one hand, 

 traces only may be found, which may be normal ; while, on the other 

 hand, the daily excretion may exceed 1000 grammes. In diabetes 



