334 R. R. BENSLEY 



As a result of my observations and experiments I am thus 

 forced to conclude that prolonged activity provoked by the injec- 

 tion of a solution of dog secretin into the dorsal lymph sac of the 

 toad is without influence on the number of islets, or on the quan- 

 tity of islet tissue in the pancreas of this animal, as it is without 

 influence under similar experimental conditions in the mammal. 



3. The effect of inanition on the number of islets of Langerhans 

 in the pancreas of the guinea pig 



The claim that the islets of the pancreas are increased when 

 exhausted by prolonged hunger was first advanced by Stat- 

 kewitsch ('94) in connection with his general studies of the effect 

 of starvation on various tissues. This claim was again advanced 

 by Dale ('05), who based his conclusion on the examination of a 

 single animal, a cat, concerning whose condition he judged on 

 the basis of its extreme emaciation and the emptiness of its stom- 

 ach and small intestines. In the pancreas of this animal he says 

 that "sections from the splenic end showed a pancreas of the 

 discharged type, though a few zymogen granules were present. 

 There was a great abundance of large islets with clear evidence 

 of progressive formation, as in the gland exhausted by secretin. 

 . . . . The examination of this one specimen entirely cor- 

 roborates the statement of Statkewitsch." The point of view 

 from which this statement proceeds is well brought out by Star- 

 ling in his "Recent advances in the physiology of digestion" 

 where he says (p. 100) : 



Complete exhaustion thus causes, not only an extrusion of the whole 

 of the secretory granules, but also an emptying out and disappearance 

 of the whole of the basophile protoplasm. It is worthy of note that the 

 proportion of islet tissue to secreting tissue is increased, not only by the 

 prolonged activity, but also by the prolonged inactivity which occurs 

 during starvation. In the latter case the gland, which is not required 

 for digestion, is called upon to give up its stored material, whether 

 granules or protoplasm, to serve as food for the working of those parts 

 of the body whose continuous activity is a condition of the maintenance 

 of life. In the process of wasting the same changes are brought about 

 in the appearance of the cells as when the discharge of their constituents 

 is required for the production of a juice for the purpose of digestion. 



