AND DIABETES 107 



quite so far ; a little of the pancreatic secretion con- 

 tinues to be supplied, and if carefully husbanded, 

 as by reducing the carbohydrate in the food, may 

 suffice for the bare needs of the body. To return to 

 the illustration, the hungry boy is not quite penniless, 

 and if he spends his money wisely he may yet keep 

 himself going by alternating periods of self-denial 

 and mild indulgence. 



Various authorities have tried to go further with 

 the explanation of human diabetes, and have stated 

 that the internal secretion is derived from the clusters 

 of cells called islets of Langerhans, whereas the 

 digestive juices are derived from the acini ; it has 

 further been stated that in diabetes sometimes the 

 islets are destroyed whilst the rest of the pancreas is 

 normal. It is very doubtful, however, whether the 

 islets are more than gland acini exhausted by secre- 

 tion (Dale). 



Again, such wide currency has been given to an 

 experiment of Cohnheim's, that it is necessary to 

 state and refute it. He taught that muscle extract 

 with pancreatic extract was able to break down 

 sugar, but that neither was able to do so without 

 the other. It has since been abundantly proved 

 that muscle extract can break down sugar just as well 

 by itself. Von Noorden considers that the pancreatic 

 secretion is necessary to enable the tissues to build 

 up sugar (C 6 H 12 O 6 ), into the more complex glycogen 

 (C 6 H 10 O 5 ) n , where the n may stand for a very high 

 figure ; glycogen he takes to be a necessary stage in 

 the absorption of sugar into the molecule of proto- 

 plasm. Certain it is that both in experimental and 



