LECTURE VII. 



THE NORMAL EXCITANTS OF THE NERVOUS ME- 

 CHANISM OF THE PANCREAS: SUMMARY OF 

 MATTERS DEALT WITH, AND PROBLEMS FOR 

 FURTHER INVESTIGATION. 



Acidity is ,1 powerful excitant of the pancreatic gland The specific 

 properties of this excitant The stomach contents on passing into the 

 duodenum, excite the pancreas chiefly because of the acid reaction of the 

 gastric juice The acid reflexly excites the pancreas by acting on the 

 duodenal mucous membrane Probable significance of the relationship 

 established by the acid between the gastric and pancreatic secretions- 

 Starch does not augment the secretion of the pancreas, but does increase 

 its content of amylolytic ferment. Fat is a reliable exciter of pancreatic 

 secretion, and also increases the amount of fat-splitting ferment in the 

 juice Sleep does not hinder pancreatic secretion Although psychic ex- 

 citation of the pancreas may be accepted as existing, yet it plays only an 

 unimportant rule. Water is an independent exciter of the pancreas Solu- 

 tions of neutral and alkaline salts of the alkalies inhibit pancreatic 

 secretion Grouping of problems still to be investigated in connection 

 with the work of the digestive glands The definite establishment of a 

 specific excitability of the digestive canal constitutes the fundamental 

 result of all the experiments related Summary of the results from 

 a general point of view Outlook and programme of future investigations. 



GENTLEMEN, In turning, in our lecture to-day, to the questions as to 

 when, how, and by what means the nervous mechanism of the pancreas 

 comes to be excited during digestion we must from the beginning ex- 

 pect to encounter both complicated relationships and unexpected facts. 

 The secretion of the pancreas is richer in ferments than that of the 

 stomach and, moreover, it is a supplementary fluid which works on food 

 already affected by a previous agency, and which has consequently 

 to adapt itself to peculiar chemical conditions. The difficulties of inves- 

 tigation which arise from these sources are, however, considerably dis- 

 counted by the following advantage. The intestinal canal is completely 

 separated from the lumen of the gland, and consequently there can be 

 no question of a direct penetration of the food into the gland ducts. 



