36 Society for Experimental Biology and Medicine. 



even if a large section- of the latter is removed, the peristalsis 

 appears in the lower segment in due time after each deglutition as 

 long as the vagus nerves remain intact. 



Recently secondary peristalsis was studied in the esophagus 

 of dogs, in which animals it appeared promptly and was easily 

 demonstrable. The bolus consisted mostly of a piece of absorbent 

 cotton attached to the middle of a long thread, one end of which 

 ran through an opening in the floor of the mouth and the other 

 through an opening in the stomach. The animal was of course 

 narcotized but anesthesia interferes greatly with both forms of 

 peristalsis. The observations however were made when the 

 animal recovered from the anesthesia. It was found that the 

 bolus went down to the stomach from any part of the esophagus 

 without being started by a preceding deglutition. The bolus 

 had to be of a certain size ; if too small it was either without 

 effect or the effect set in late and the movement was slow and 

 irregular. When the bolus was kept by force in one place for a 

 long time that place lost the promptness of its irritability. It re- 

 covered this again, however, a few minutes after the removal of 

 the bolus. I shall not enter upon further particulars except to 

 mention the observation made by Dr. Auer and myself that sec- 

 tion of one vagus will remove the secondary peristalsis, while the 

 primary peristalsis is but very little affected. 



The chief object of the present communication was a demon- 

 stration of both forms of peristalsis in a dog with a permanent 

 fistula in the upper half of the cervical esophagus. I introduced 

 into the fistula an olive-shaped body of hard rubber to which a 

 long thread was attached. The thread ran over a rod and had a 

 paper fan at the opposite end. When the olive-shaped body trav- 

 eled down into the stomach the fan was observed to move upwards. 

 When the olive-shaped body was placed into the lower half of 

 the cervical esophagus it remained in that place without moving 

 downwards. A deglutition, on the other hand, carried it down 

 into the stomach. But when the olive-shaped body was placed 

 into any part of the thoracic esophagus it was promptly carried 

 down into the stomach without the aid of a preceding deglutition. 

 When the olive-shaped body was held back by force for some 

 time, it was not carried down spontaneously — a deglutition, how- 



