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CHAPTER IV 



THE QUANTITATIVE LAWS OF DIGESTION AND 



RESORPTION 



We now proceed to consider life-processes, in which 

 not simple cells but higher organisms are involved. 

 The question which has been investigated in this 

 field because of its extreme importance is the 

 digestion of food in higher animals. For the ex- 

 periments dogs have been usually examined. 



When we consider digestion in the stomach of an 

 animal, wefind the circumstances rather different from 

 those for digestion in vitro. Our chief knowledge 

 we owe to the investigations of Pawlow in Petro- 

 grad and his school, especially Professor London. 

 He gave me his figures for calculation, and I found 

 some very pronounced regularities in them, which 

 also occur in the observations of Khigine and other 

 pupils of Pawlow. A short review of the chief 

 results which may be expressed by quantitative laws 

 may not be out of place here. 



The observations were made in the following 

 manner. Fistulae were opened to different parts of 

 the digestive canal of the observed animal. After 

 the introduction of food into the stomach — which 



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