244 APPLIED PHYSIOLOGY 



of the two parts occurs. The fundus serves the function 

 of a reservoir, in which the food is gradually mixed with 

 the gastric juice and slowly squeezed on into the pyloric 

 end. It is not the seat of any very active churning 

 movements, and as each bolus of food is swallowed it 

 is received into the centre of the accumulated mass, 

 where the gastric juice only slowly reaches it, thus 

 affording the saliva time to act. 



' These observations show that the order in which the 

 chief courses of a dinner are arranged is physiologically 

 suitable, as the part containing most carbohydrate comes 

 last, and so remains for a time in the fundus, where 

 salivary digestion can continue, whilst the part rich in 

 proteids passes quickly to the pyloric end of the stomach, 

 where peptic digestion begins early and salivary digestion 

 soon becomes impossible. The great importance of 

 thorough mastication and the consequent efficient im- 

 pregnation of the food with saliva is at once explained 

 by these facts. When a farinaceous meal is bolted, only 

 a very superficial layer of the masses of food can be 

 digested by the saliva. The carbohydrate is then very 

 liable to undergo bacterial fermentation with the pro- 

 duction of flatulence and all its unpleasant results. This 

 is prevented when salivary digestion can occur, as dextrin, 

 the first product of the digestion of starch, is less easily 

 decomposed by bacteria than starch, and maltose and 

 dextrose, the final products of salivary digestion, are 

 soluble and readily diffuse into the pyloric end of the 

 stomach, where the presence of hydrochloric acid prevents 

 the occurrence of bacterial decomposition ' (Hertz). 



The movements of the pyloric end of the stomach are 



