in DIGESTION IN THE MOUTH AND STOMACH 187 



tambour connected with a pneumograph. The distension of the 

 exploring balloon is regulated by raising or lowering the cylinder 

 which is fixed in a holder. 



FIG. 61. Oscillations of tone in cardiac stomach, complicated by more rapid contractions and 

 passive respiratory movements, recorded from dog, as in Fig. 60. (Ducceschi.) Time tracing 

 marks intervals of 



5 sec. 



When the sound is passed into the cardiac, fundic, or middle 

 region of the stomach in a state of comparative rest, slow, irregular 

 contractions, slight in degree, are observed, which are probably 

 automatic oscillations of tonicity in the 

 gastric muscles (Fig. 60). In a period of 

 greater motor activity, other more rapid, 

 simple contractions appear along the line 

 of this slow primary wave, which are com- 

 parable with those that commonly appear 

 in plain muscle (Fig. 61). These oscilla- 

 tions of tonus and contractions vary con- 

 siderably in duration and intensity ; they 

 are never regular and rhythmic. The 

 primary waves on an average last 50-60 

 sees., the secondary 15-30 sees. 



If the glass cylinder be somewhat 

 raised so as to increase the swelling of the 

 balloon, and with it the distension of the 

 gastric walls, another form of movement 

 appears with a highly characteristic curve. 

 This is very probably an expression of the 

 peristaltic movement propagated through 

 the stomach from cardia to pylorus. A 

 schema of this movement is shown in 

 Fig. 62. More frequently, however, the 

 tracing of this wave is less simple, and is interrupted by slight 

 notches due to the respiratory movements ; the succession of these 

 is very irregular, and abortive forms and a variety of combina- 

 tions with the oscillations of tonicity already referred to are not 



FIG. 62. Tracings of peristaltic 

 movements obtained under 

 same conditions as Fig. 60, 

 with sound introduced into 

 cardia and fundus of stomach. 

 (Ducceschi.) 



