322 The Chemical Regulation of the Secretory Process. [Mar. 21, 



by the blood to the pancreas, and there slowly gives rise to the 

 formation of lactase, which is turned out in the juice when secretion is 

 excited by the entry of acid chyme into the duodenum. We have 

 no knowledge as yet as to the nature of this substance x. All we 

 can say is that it is destroyed at a boiling temperature, since boiled 

 extracts of the mucous membrane of milk-fed dogs do not, when 

 subcutaneously injected, cause the appearance of any lactase in the 

 pancreatic juice of biscuit-fed dogs. 



Table III. — Effect on Milk Sugar of Pancreatic Juice from Biscuit-fed 

 dogs, which had received Subcutaneous Injections during 3 days 

 of Extracts of the Mucous Membrane of Milk-fed dogs. 



The figures represent c.c. of lactose solution which reduced 50 c.c. 

 Pavy's solution. 



Exp. 



Solution of 

 lactose. 



Controls. 



Lactose + pancreatic 

 juice (boiled). 



Lactose + pancreatic 

 juice. 



Percentage 

 of 



inversion. 



1.... 



7-4 





6-8 



18 -1 



2... 



8-2 



8-2 



7 6 



16-5 



3.. .. 



8-2 



8 -15 



7-85 



97 



4.. .. 



7-95 



7-9 



7'65 



8-5 



5.. .. 



7-8 





7-5 



8-8 



6.. .. 



7-0 



7-05 



6-75 



8-1 



7.... 



4-1 





3-75 



20-8 



8. . .. 



9-25 





8-2 



25 9 



Whether the qualitative adaptation of the juice in respect of its 

 trypsin, amylopsin, and steapsin is carried out in a similar fashion we 

 cannot as yet say. We hope that an investigation of the mechanism 

 of this adaptation, which is now proceeding, may throw light, not only 

 on the factors involved, but also on the nature of the substance which 

 is formed in the mucous membrane, and has this marked effect on the 

 activity of the pancreatic cells. Involving, as it does, two distinct sets 

 of cells, this chemical adaptation is more complex than any yet 

 investigated, and shows the intimate relation which must exist between 

 the chemical activities of very different organs of the body. 



