82 Swale Vincent and F. D. Thompson. 



in fact that the islets were formed fi^om the alveoli under these conditions. 

 Jarotsky^) was unable to confirm this, but Dale-) found in the cat after 

 a period of inanition a great abundance of large islets, with clear 

 evidence of progressive formation. In dogs, cats, pigeons, and frogs, 

 we have been able to fully confirm the statements of Statke witsch 

 and Dale. 



A. Effects of Inanition upon the Mammalian Pancreas. 



Dog. The diiference between a section of a normal „resting" 

 pancreas of a dog and one of a pancreas from a dog which has 

 undergone inanition for some days is so striking as to render it almost 

 incredible that observers could have disagreed on this point (cf PI. IV, 

 fig. 3 with PI. IV, fig. 5). 



For the purpose of this examination we have always compared 

 the splenic end of the pancreas in the two cases for contrast. Sections 

 fi'om the pancreas of a dog after inanition show islets of Langerhans 

 in such great numbers "and of such enormous sizes as can never be 

 encountered in any part of a normal resting gland. Thus, in the 

 drawings given (PI. IV, fig. 3 and PI. IV, fig. 5) there are only about 

 three small islets in the field in the case of the normal (PI. IV, fig. 3, i.) 

 and these do not exceed a size of about 90 x 30 /< , whereas in 

 the pancreas after inanition, there are about 16 in the field, of which 

 the largest reach 330 X 70 ^i (PI. IV, fig. 5, L). 



One of the most significant features in the large islets of the 

 inanition pancreas is the obvious suggestion of alveolar structure. 

 There can, we think, be no doubt that they have been formed by a 

 variation of the secreting alveoli. These inanition appearances are an 

 exaggerated phase of a condition we have already described in the case 

 of the normal pancreas. The solid columns in the islet can be seen here 

 and there to shade off into the secreting tubules (PI. IV, fig. 5, trans, c), 

 the cells in an intermediate zon« having some zymogenous granules, 

 and, generally speaking, a structure intermediate l)etween the type of 

 islet ami zymogenous cell. Thus it may be said that in these largii 



'; Viicliows Anil. lid. I-.C. S. Id'.t. IS'.)!», 

 «j Loc. cit. 



