2 4 



whether the mechanism in this case also is chemical. An apparent 

 example of adaptation of the pancreatic activity to the nature of the food 

 was described in 1901 by Weinland, who stated that, whereas the pan- 

 creatic jnice of an ordinary adult dog contains no lactase and is therefore 

 without effect on milk sugar, it is only necessary to feed the dog for some 

 time, a week or more, with milk or with milk sugar in order to determine 

 the appearance of lactase in the pancreatic juice. These experiments of 

 Weinland were confirmed and amplified more recently by Bainbridge, 

 who endeavoured also to determine the mechanism by which the adaptation 

 was carried out, and especially to decide the question whether it were 

 of a nervous or of a chemical nature. 



(More recent work by Bierry has thrown doubt on this adaptation of 

 the pancreas to lactose. Dr. Plimmer has therefore reinvestigated the 

 whole question, using more accurate methods than either Weinland or 

 Bainbridge, and has proved conclusively that under no circumstances 

 does the pancreas or pancreatic juice contain lactase. I am therefore 

 inclined to accept Popielski's view as to the absence of any qualitative 

 adaptation of the pancreas to the nature of the food at all events until 

 further experimental evidence has been brought forward for such 

 adaptation. Note added December is/, 1905.) 



