218 



Dr. J. T. Cash. 



Experiment II (Chart I (continuous line, diagrammatic), and 

 Curve I). — The dog had not been fed for nineteen hours. A small 

 sound consisting of ^ gram of lean meat on which a little piece of 

 tendon was left, was attached by a thread to the pen already 

 described which moved vertically upon guides. 



This sound was introduced deeply into the upper fistulous opening. 



The following notes indicate its progress through the fistula : — 



Experiment II, Curve I. 



Keduced scale = 4th. 



0'. Sound introduced into the intestine. 

 4'. Definite peristalsis has commenced ; animal sleeping. 

 7'. Roused ; a little movement with deep respiration. 

 17'. Again asleep; gentle peristalsis. 



19'. Started in sleep and awoke. The loop of intestine was evi- 

 dently twisted or moved away from former position (roll move- 

 ment) to which it shortly returned ; again sleeping. 



21' 5". Roused. Deep respiration with slight peristalsis. 



33'. Propulsive peristalsis, strong and regular. 



Dog roused just before expulsion of sound from the lower 

 opening. (The meat was not in the least degree digested.) 



It will be observed that during sleep the sound continues to travel 

 forwards with considerable regularity. In all 12 cm. of the fistulous 

 intestine is traversed in forty minutes. 



The experiments of Ranvier have shown that if a travelling sound 

 which is passing down the oesophagus be hindered in its transit by 

 traction being exerted upon a thread connected with it, the contrac- 

 tions become inoperative, i.e., fail to forward the body, and then 

 cease, the muscular tube becoming "accustomed" to its presence. 

 The same holds good if we introduce a moderately large sound into 

 the intestinal fistula and allow it to travel. The fact of its introduc- 

 tion and presence favours its passage onwards for a certain distance 

 with considerable rapidity ; but if gentle traction be made on the 

 thread after a period of active but futile contraction,* rest occurs and 

 no advancement takes place till a new phase of activity develops itself. 



* These contractions are local. I have hardly ever seen them pass the body 

 whose presence is to a large degree the cause of their occurrence and travel to a lower 

 part of the intestinal tube. 



