290 DIGESTION. 



speak, of the alimentary mass are going on, the food is turned 

 over and over, so that it becomes intimately mixed with the 

 digestive fluids and subjected to a certain amount of tritura- 

 tion. This action is undoubtedly of great importance, as 

 fresh portions of food are thereby continually exposed to the 

 action of the gastric juice, and the boluses, with their particles 

 agglutinated to a certain extent in the mouth, are disinte- 

 grated and penetrated with the gastric fluid in every part. 



A marked difference was observed between the move- 

 ments in the cardiac and in the pyloric portion. "When the 

 thermometer-bulb arrived at the contracted septum, which 

 was three or four inches from the pyloric end, it was at first 

 stopped by the forcible contraction; but in a short time 

 there was a gentle relaxation which allowed it to pass, when 

 it was drawn quite forcibly for three or four inches toward the 

 pyloric opening. "When in this portion of the stomach, the 

 bulb was firmly grasped and made to undergo a spiral mo- 

 tion ; and if drawn forcibly out, it gave to the fingers the 

 sensation of being held by a strong suction force. As soon 

 as relaxation occurs, the bulb is passed back to the seat of 

 stricture, and when pulled through this, it moves freely in 

 the great cavity. 



Each one of these revolutions was found to occupy from 

 one to three minutes. They were slower at first than after 

 digestion had been somewhat advanced. 1 



The mechanism of these movements is easily appreciated 

 when we consider the number and varied direction of the 

 fibres which form the muscular coat of the stomach, and the 

 fact that the stomach, when distended, is more or less dis- 

 placed with every movement of the diaphragm. It is easy 

 to understand, also, how in the pyloric portion, where the 

 muscular fibres are thickest and the cavity is comparatively 

 small and elongated, the movements should be more vigorous 

 and expulsive than over the rest of the organ. We have 

 already alluded to the fact that the movements of the stom- 



1 BEAUMONT, op. cit., p. 109 at seq. 



