480 DIGESTION. 



The fundus part is therefore less a digestion-organ than a storage-organ, 

 and in the interior of the same, the food may remain for hours without 

 coming in contact with a trace of gastric juice. 



What has been said above applies at least to solid food. We have 

 no extensive observations on the behavior of fluids or semifluid food. 

 According to GRUTZNER, in these cases, as well as in the above-mentioned 

 experiments, the swallowed foodstuffs are not irregularly mixed together. 

 Fluids quickly leave the stomach, which is also the case with a mixture 

 of solid and fluid food. 



Milk is an exception because it coagulates and the clot remains in the 

 stomach while the whey quickly leaves the stomach. 



The fact that only that part of the ingesta lying on the mucous 

 membrane is mixed with gastric juice, while the mass in the interior is 

 not acid in reaction, is of special importance for the digestion of starches 

 in the stomach. By this we can explain why the salivary diastase, 

 although sensitive toward acids, can continue its action for a long time 

 in the contents of the stomach. That this is true was first found by 

 ELLENBERGER and HOFMEISTER and then by CANNON and DAY 1 by 

 special experiments upon animals. The occurrence of sugar and dex- 

 trin in the contents of the human stomach has been repeatedly observed. 

 In carnivora, whose saliva shows scarcely any diastatic action, it is 

 a priori not expected that there should be a diastatic action in the 

 stomach, but the conditions are different in herbivora, where an abun- 

 dant digestion of starch takes place in the various stomachs, according 

 to the different species. 



The gastric contents which have been prepared in the pylorus part 

 are passed through the pylorus into the intestine intermittently. This 

 material is generally fluid, but it is possible that pieces of solid food 

 may also occur, and this has often been observed. Thin or plastic 

 food leaves the stomach earlier than solid food, and it is obvious that the 

 time in which the stomach unburdens itself depends naturally upon 

 the coarseness or fineness of the food. This depends essentially upon 

 the reflex action- of the stomach or intestine, causing an opening or 

 closing of the pylorus, which action is dependent upon the quantity and 

 character of the food, the amount of fat, and the degree of acidity in 

 the contents of the stomach and intestine. The emptying of the food 

 into the small intestine causes, as shown by PAWLOW, a closing of the 

 pylorus by chemo-reflex in which the hydrochloric acid and the fat take 

 part, and we thus find in this regard an alternate action between the 

 stomach and duodenum. 



1 Ellenberger and Hofmeister, Maly's Jahresb., 15 and 16; Cannon an 1 Da/, Amer. 

 Journ. of Physiol.. 9. 



