2:U 



AN AMERICAN TEXT-BOOK OF PHYSIOLOGY 



the loss of the granular material, so that the cell as a whole is smaller in 

 size than in the gland from the fasting animal. It seems evident that during 

 the hours immediately following a meal — that is, at the time when we know 



Fig. 59.— Pancreas of dog during first stage of digestion ; alcohol, carmine (after Heidenhain). 



that the gland is discharging its secretion, the granular material is being used 

 up. After the cessation of active secretion — that is, during the tenth to the 

 twentieth hour after a meal in the case of a dog fed once in twenty-four 



Fig. 60.— Pancreas of dog during second stage of digestion; alcohol, carmine (after Heidenhain). 



hours — the gland-cells return t<> their resting condition (Fig. 60). New gran- 

 ules are formed, and finally, if the gland is left unstimulated they fill the 

 entire cell except for a narrow margin at the basal end. 



Similar results are reported by Kiiline 1 and Lea from observation^ made 

 upon the pancreas cells in a living rabbit. In the inactive gland the outlines 



1 Untertuchungen aua dem phyriologischen Institut des Universitats Heidelberg, 1882, Bd. ii. 



