30 PROFESSOR D. J. CUNNINGHAM 



but includes also the left portion of the body of the stomach. Over the pyloric part, 

 which thus represents rather more than the right half of the stomach, " constriction- 

 waves are seen continually coursing towards the pylorus." Each wave takes about 

 thirty-six seconds to pass from the middle of the stomach to the pylorus, and the 

 different waves follow each other at intervals of ten seconds. As they pass the incisura 

 angularis, this indentation in the lesser curvature becomes deeper. The fundus (or left 

 half of the stomach, as understood by Cannon) acts in a totally different manner. It 

 "is an active reservoir for the food, and squeezes its contents gradually into the 

 pyloric part." 



The stomach is emptied by the conversion of the right half of its body into a tube, 

 and over this constriction -waves are observed to pass. The rounded or spherical 

 cardiac sac (Cannon's fundus), shows no peristaltic movement of its walls, but, by the 

 firm, steady contraction of its musculature, its contents are by degrees pressed into the 

 tubular portion of the stomach, and the whole length of this tube is " slowly cleared of 

 food by the waves of constriction." 



The investigations by Rossbach (45) into the movements of the stomach of the dog 

 during digestion, undertaken eight years earlier, yielded results which closely correspond 

 with those obtained by the more refined method of Cannon, but they differ in regard 

 to the manner in which the stomach is emptied. Rossbach considers that during the 

 whole period of gastric digestion the pyloric sphincteric ring remains closed, and only 

 at the end of the process does it relax so as to allow the contents of the stomach to be 

 discharged into the intestine. Hirsch and Cannon, however, have brought forward 

 very conclusive evidence to show that the discharge takes place intermittently — not at 

 the approach of every wave, but at irregular intervals, according to the condition of the 

 food which reaches the pyloric canal. 



MM. Jean-Ch. Roux and V. Balthazard (46) have likewise, by the employment 

 of the same method, obtained results which correspond very closely with those of 

 Cannon, and especial interest attaches to the observations of these investigators, 

 inasmuch as part of their work was carried out on the human subject. Their conclusions 

 may be given in their own words (47): "Nous concluons done que chez l'homme, 

 comme chez le chien, comme chez la grenouille, au point du vue fonctionnel, l'estomac 

 se devise en deux regions distinctes : la plus grande partie de l'estomac sert de reservoir 

 aux aliments, la portion prepylorique est seul l'organe moteur de l'estomac, et par de 

 violents mouvements peristaltiques, elle chase peu a peu dans le duodenum les matieres 

 accumulees dans l'estomac. " 



In the light of these investigations, I think that there can be little doubt that 

 the stomach represented in Plate III. fig. 23 represents the functional phase so 

 graphically described by Cannon, in which the organ is being gradually emptied. 

 We have the spherical cardiac sac still holding a considerable amount of undigested 

 food, and the long tubular part composed of two different portions of the stomach, 

 viz. one formed by the right half of the body of the stomach (Cannon's preantral 



