38 Mr. F, A. Bainbridge. [May 25, 



pancreatic juice. Consequently, the lactase of the pancreas is not 

 taken up as such from the blood, but must be formed by the pancreas 



itself. 



Weinland's observation that lactose injected subcutaneous ly did not 

 cause the formation of lactase by the pancreas, led to the inference 

 that the intestinal mucous membrane must be concerned in the pro- 

 duction of lactase. I therefore made secretin from a milk-fed dog 

 and injected it into a biscuit-fed dog, but the pancreatic juice of the 

 latter contained no lactase. Then the intestinal mucous membrane of 

 a biscuit-fed dog was ground up with sand and a strong solution of 

 lactose. After standing for some hours, the fluid was filtered off* and 

 injected into a second biscuit-fed dog. Ordinary secretin was also 

 injected and the pancreatic juice collected ; it contained no lactase. 



The influence of lactase injected into the gut during life was then 

 investigated. A strong solution of lactose was injected into the 

 intestine of a biscuit-fed dog, and after 1 J hours, secretin was injected, 

 and the pancreatic juice collected and examined ; no lactase was 

 present. 



The intestinal mucous membrane of this dog was extracted with 

 sand and water, filtered and injected intravenously into a second dog 

 (also biscuit-fed). After waiting H hours, the pancreatic juice was 

 collected and examined ; slight inversion occurred, so that the pancreas 

 had secreted some lactase. 



Then the intestinal mucous membrane of a kitten fed only on milk 

 was extracted and intravenously injected into a dog ; after two hours 

 the pancreatic juice was collected and found to contain lactase, as the 

 following figures show : 



Pure lactose 8*8 c.c. ^ 



Lactose and pancreatic juice of = 50 c.c. Pavy's 



dog injected with extract of solution. 



kitten's gut 8*0 ,, J 



Inversion of 22 per cent, of the lactose. 



A modification of this method was subcutaneously to inject into 

 biscuit-fed dogs a CHC1 3 water extract of intestinal mucous membrane 

 of kittens or of milk-fed dogs. Two injections were made on successive 

 days, and on the third day the pancreatic juice was collected and 

 examined. In all these cases lactase was produced, as shown by the 

 following table : 



