THE FUNCTIONS OF THE DIGESTIVE ORGANS. 521 



of this adjustment to the different foodstuffs is easy to understand, 

 when we point out that the bile assists the action of the pancreatic juice 

 by accelerating the action of the ferments. It affects the fat-splitting 

 ferments most, but it also increases the action of trypsin and diastase. 

 Bile, consequently, is concerned not alone with the digestion of fat, but 

 influences considerably that of the other foods. It assists the transference 

 of the seat of digestion from the stomach to the intestines, probably by 

 preventing the further action of pepsin. 



The functions of the bile are not, in general, considered to be as impor- 

 tant as would seem probable from the researches of Pawlow. It has been 

 found, in fact, that the bile may be entirely excluded from the intestines 

 without any serious disturbance taking place, provided the food be prop- 

 erly chosen. It would be wrong to conclude from this that the bile is 

 of little importance in the digestive process, for even with complete extir- 

 pation of the pancreas, digestion does not cease entirely. The animal 

 organism possesses ways and means of replacing, to some extent at least, 

 lost functions. The ferments of the pancreatic juice can indeed perform 

 their work without the aid of the bile, but it requires more time. Even 

 then a part of the fat will be absorbed. There are no exact experiments 

 to indicate the effect of the loss of the bile upon the metabolism as a 

 whole. Its absence is not without influence, because it is then necessary 

 to choose the food more carefully. Food rich in fat must be avoided. 

 We merely wish to emphasize the fact that it does not follow because an 

 animal is able to exist without a certain function, and even be kept in 

 good health, that the function is perfectly dispensable. Thus we should 

 make a serious error if we reasoned that because a man could live without 

 a stomach that this organ occupies physiologically a subordinate posi- 

 tion. We must accustom ourselves to have in mind the working together 

 of all the organs, and never follow the functions of a single organ only 

 under certain special conditions but under as many different conditions 

 as possible, and especially under those which occur normally. Only in 

 such cases are we able to form a proper judgment as to the relative value 

 of the functions of a given organ. 



Now that we have traced the transition between the digestion of the 

 stomach and that of the intestines, we must turn our attention especially 

 to the functions of the pancreatic juice. This contains, as we have stated 

 repeatedly, three ferments, trypsin, steapsin, and a ferment which has 

 a diastatic action. While it has not yet been established positively that 

 the last ferment is secreted originally in a zymogen condition, this is surely 

 the case with the two other ferments, trypsin and steapsin. Trypsinogen 

 is, according to the important observations of Pawlow, activated by a 

 substance which occurs in the intestinal juices. Pawlow called this 

 substance enterokinase. It is very likely that this substance itself belongs 



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