Scientific Proceedings. 



35 



of the shape of the abdomen, it is difficult to prevent the occur- 

 rence of congestion of the kidney. This occurs because of com- 

 pression of the renal vein between the aorta and the kidney. It 

 could be prevented by putting the new kidney exactly at the place 

 of the extirpated one. 



This operation is not dangerous. Of seven animals operated 

 on, six remained in good health. The seventh died of intestinal 

 intussusception four days after the operation. 



29 (172) 



Secondary peristalsis of the esophagus — a demonstration on 

 a dog with a permanent esophageal fistula. 



By S. J. MELTZER. 



\_From the Rockefeller Institute for Medical Research^ 



The peristalsis of the esophagus with w r hich every one is familiar 

 is that which follows an act of deglutition. About a year ago I re- 

 ported to this society that experiments which I had made on rabbits 

 demonstrated that the esophagus is capable of peristaltic move- 

 ments not initiated by deglutitions. Injections of indifferent solu- 

 tions or of air directly into the esophagus cause there a regular 

 peristaltic movement. This latter form of peristaltic movement, 

 which for the sake of brevity I shall henceforth term secondary 

 peristalsis, differs from the primary peristalsis, the one which follows 

 deglutition, essentially through the nervous mechanism by which 

 it is controlled. All the movements of the complicated act of 

 deglutition are managed by a reflex mechanism, with only one 

 sensory stimulus for its initiation and a series of consecutive motor 

 impulses going to every part of the long path of deglutition ; it is 

 practically a single reflex. The reflex mechanism of the secondary 

 peristalsis, on the other hand, consists of a chain of reflexes ; each 

 part of the esophagus sends up to the center a sensory impulse 

 started by the presence of the bolus in that part and receives in 

 turn a motor impulse. The secondary peristalsis therefore requires 

 the presence of some sort of a bolus within the esophagus and 

 presupposes the integrity of the latter ; whereas the primary peri- 

 stalsis requires neither a bolus nor the integrity of the esophagus; 



