THE INTERNAL SECRETION OF THE PANCREAS 435 



Diamare, Visentini, &c.) ; while others (Hansemann, Gutmann, 

 Karakascheff, Herxheimer, Schmidt) ascribed the internal secre- 

 tory function to the acini. Others, again (Reitmann), adopted 

 the view that both pancreatic tissues are concerned in the etiology 

 of diabetes. According to Lombroso, the anatomico-pathological 

 findings are distinct evidence against the assumption that the 

 internal secretion of the pancreas is the function of one tissue 

 formation only, whether of the acini or of the islands of Langer- 

 hans. 



Experiments undertaken with the object of ascertaining the 

 structural changes in the pancreas, which follow the exhibitioi/ 

 of substances believed to have an action in increasing or diminish 

 ing the hormone production, have also yielded contradictory 

 results. Ssobolew and Lepine found that, in the dog and the 

 guinea-pig, the intravenous injection of grape-sugar was followed 

 by a reduction in the size of the islands and by a diminution in 

 the number of granules in the island cells ; while Diamare, on 

 the contrary, observed a remarkable profusion of granules in the 

 island cells of a Teleostean (Motella tricirrata), of frogs, and of 

 guinea-pigs. Marrassini describes hypertrophy of the islands of 

 Langerhans in rabbits, where prolonged administration of grape- 

 sugar was accompanied by continued glycosuria, and this hyper- 

 trophy was of so intense a nature that the neighbouring acini 

 were flattened, deformed and atrophied. The island cells con- 

 tained an enormous number of fine fuchsinophile granules. Re- 

 ports of the effects produced by the injection of phlorizin and 

 adrenalin upon the structure of the pancreas are equally con- 

 tradictory. After the repeated injection of phlorizin into dogs, 

 Ghedini observed a marked reduction in the volume of the pan- 

 creas, due to degenerative atrophy and necrosis of the acinous 

 tissue, no cell changes taking place in the islands. Lazarus 

 described marked hyperplasia and hypertrophy of the islands of 

 Langerhans in guinea-pigs after prolonged treatment with phlori- 

 zin and adrenalin, and here also the acinous tissue was unchanged. 

 After the administration of adrenalin, Herter and Wakeman found 

 necrosed foci in the pancreas and changes in the cells of the 

 islands of Langerhans ; in chronic poisoning with arsenic, mor- 

 phia, and phosphorus, Carnot and Amet found hyperplasia, to- 

 gether with frequent fatty degeneration, of the islands. Lepine 

 and Vigliani observed absolutely normal histological conditions 

 after the exhibition of phlorizin ; and Tiberti reports similar 

 findings after the injection of phlorizin and adrenalin, as the 

 result of his very careful experiments with guinea-pigs and 

 rabbits. The latter author, like Heiberg, believes that the hyper- 

 trophied islands which Lazarus described are normal formations 

 in the pancreas of guinea-pigs. 



A second experimental method of physiological differentiation 

 between the two tissues of the pancreas seemed to promise better 



