54 (224) Society for Experimental Biology and Medicine. 



impulse, the impulse traveling further within the center, while in 

 anesthetized animals the progress of the peristalsis is furthered by 

 a chain of local reflexes. 



On reinvestigating this problem the author recently found that 

 this chain of local reflexes exists also in the normal, non-anesthe- 

 tized animals when ordinary stimulation is avoided. The experi- 

 ments were made on rabbits. A cannula was tied in the upper end 

 of the esophagus. When any indifferent liquid was injected directly 

 into the esophagus, instead of being introduced by way of the 

 mouth, a peristaltic wave ran down the esophagus, terminating in a 

 contraction of the cardia just as after a normal deglutition. When 

 the esophagus was ligated the wave stopped at the ligature. This 

 happened whether the animal was deeply anesthetized or was 

 awake. That the wave of peristalsis was a reflex phenomenon, 

 and not simply due to the mechanical effect of the injections was 

 proved by cutting the vagi. In this case the injections simply 

 filled up the esophagus without causing any peristaltic waves or any 

 contractions of the cardia. Better than cutting was the painting of 

 the vagi with cocain or with magnesium sulfate. In these cases the 

 nerves could be restored by irrigation and the experiment repeated 

 many times. A similar wave of peristalsis was obtained when the 

 liquid was injected through the cardia upward through a catheter. 

 The peristalsis began at a point just above the highest drop of 

 liquid. The wave always ran towards the stomach and against the 

 stream, even if the animal was kept head downward. The peri- 

 staltic wave could also be produced by merely injecting air into the 

 esophagus either from above or from below. This explains a fact 

 which the author recorded 23 years ago, namely, that each act of 

 " belching " is followed by a peristaltic wave of the esophagus. 



The author found that this chain of local reflexes is very 

 resistant to ether anesthesia ; it disappears at about the same time 

 that the lid reflex is abolished, and returns as soon as the ether is 

 discontinued. 



The experiments demonstrate that the function of deglutition 

 is provided with two sets of reflex mechanisms. One mechanism 

 has only one initial afferent impulse which travels within the center 

 independently of any further aid from the esophagus ; it is very 

 sensitive to anesthesia and we may call it a higher reflex. The 



