320 DIGESTION. 



membrane, which also seems to possess the power of con- 

 verting starch into sugar. 



2. The existence of a pancreas in Carnivora, which have 

 little or no starch in their food, and the results of various 

 observations and experiments, leave very little doubt that 

 the pancreatic secretion also assists largely in the digestion 

 of fatty matters, by transforming them into a kind of 

 emulsion, and thus rendering them capable of absorption 

 by the lacteals. Several cases have been recorded in which 

 the pancreatic duct being obstructed, so that the secretion 

 could not be discharged, fatty or oily matter was abun- 

 dantly discharged from the intestines. In nearly all these 

 cases, indeed the liver was coincidently diseased, and the 

 change or absence of the bile might appear to contribute 

 to the result ; yet the frequency of extensive disease of 

 the liver, unaccompanied by fatty discharges from the 

 intestines, favours the view that, in these cases, it is to the 

 absence of the pancreatic fluid from the intestines that the 

 excretion or non- absorption of fatty matter should be 

 ascribed. In Bernard's experiments too, fat always ap- 

 peared in the evacuations when the pancreas was destroyed 

 or its duct tied. Bernard, indeed, is of opinion that to 

 emulsify fat is the express office of the pancreas, and the 

 evidence that he and others have brought forward in sup- 

 port of this view is very weighty. The power of emulsi- 

 fying fat, however, although perhaps mainly exercised by 

 the secretion of the pancreas, is evidently possessed to 

 some extent by other secretions poured into the intestines, 

 and especially by the bile. 



3. The pancreatic secretion has been supposed to dis- 

 charge a third function, namely, that of dissolving albu- 

 minous substances. It is very doubtful, however, whether 

 its effect in this way is more than a slight one ; and, at 

 any rate the function is quite subordinate to the other two 

 that have been mentioned. 



