in DIGESTION IN THE MOUTH AND STOMACH 191 



becomes disorganised, antiperistaltic waves occur, or there is 

 tetanic contraction of the walls (Figs. 65 and 66). 





FIG. 65. (Left.) Tracing 01 pyloric rhythm and its modifications under rapid mechanical 

 excitation. (Ducceschi.) At A, the experimenter jerked the sound. Time tracing marks each 

 5 sec. 



FIG. 66. (Right.) Tracing from fundus of stomach. (Ducceschi.) At A, a marked increase of 

 movement was obtained by rapidly shifting the sound. 



As regards the chemical stimuli that excite movements in the 

 stomach, Briicke ascribes great importance to the acid content of 

 the gastric juice, and proves that the movements are more or less 

 energetic in proportion with 

 the digestive work. Accord- 

 ing to Schiff, on the other 

 hand, chemical stimulation 

 of the stomach is more par- 

 ticularly due to copious 

 absorption of the digestive 

 product (peptone), which is 

 supported by the fact that 

 towards the end of digestion 

 there is constant reinforce- 

 ment of the movements of 

 the stomach. 



Ducceschi, to test these 

 views experimentally, intro- 

 duced 30-50 c.c. of 0*15 per 

 cent HC1 in the vicinity of 

 the exploring balloon, and found that in the region of the cardia 

 and fundus, particularly in the former, movements were clearly 

 excited, so much so as to produce typical peristaltic waves 

 (Fig. 67). In the region of the antruin, on the contrary, he 

 obtained quite different results ; a O'l per cent solution of acid 



FIG. 67. Tracing from cardiac stomach in which 

 peristaltic movements were excited by introduc- 

 tion of HC1 solution. (Ducceschi.) At 0, 40 c.c. 

 of 0'25 per cent HC1 were injected near the ex- 

 ploring balloon. 



