EXPERIMENTAL DIABETES 379 



and by the proteid which had meanwhile undergone metabolism 

 as indicated by the excretion of nitrogen. 



As a matter of fact, Hartohg and Schumn ( 36 ) have found in 

 phloridzin-poisoned dogs, at a late stage of the diabetes, D : N 

 ratios of 10-6 (for two days), and 13 (for one day) ; and Rumpf ( 37 ) 

 records a case of D. mellitus in which during fifteen days on a 

 limited diet the sugar excretion was 1169-8 grm., and that of nitrogen 

 98-8 grm. (D : N ratio 11-8). In neither of these cases could much 

 glycogen have been present in the organism to account for the 

 high sugar excretion. 



The fatty acid portion of neutral fat cannot probably be con- 

 verted into sugar, and this may possibly explain why volatile 

 fatty acids occur in the urine in severe Diabetes mellitus. 



These results would seem at least to suggest that fat may be 

 one source of the sugar. That it cannot, however, be the only 

 source, will be evident after we have considered somewhat more 

 fully how proteids themselves can be converted into sugar. 



Falta and Mohr ( 2 ) have noticed that the increased excretion 

 of dextrose which often follows proteid feeding in diabetes depends 

 largely on the ease with which the proteid in question can undergo 

 metabolism in the organism. Falta found that casein caused a rise 

 in the dextrose excretion in a case of Diabetes mellitus of medium 

 severity, whereas egg albumin and serum globulin did not. Apart 

 from showing us that the excretion of dextrose does not depend 

 on the presence of a carbohydrate group in the proteid molecule 

 for casein contains no such group, whereas egg albumin and 

 serum globulin do this result shows us that the more easily 

 the proteid is made use of by the body the more likelihood is 

 there of its influencing the excretion of dextrose, casein being more 

 easily assimilated than egg proteid. It would appear that the 

 sugar derived from casein is too quickly produced to be converted 

 into glycogen the power of effecting this transformation being 

 probably depressed in diabetes so that it accumulates in the 

 blood, causing hyperglycsemia ; whereas, from egg albumin and 

 serum globulin, this sugar is produced slowly enough for the 

 organism to deal with it and convert it into glycogen. 



In contrast to the small amount of sugar which can be ob- 

 tained in the laboratory from proteid, we see that in the 

 organism a large amount must be derived from this source. This 

 fact compels us to consider the question of sugar formation in the 



