8 Society for Experimental Biology and Medicine. 



and frequent contractions of the ureter offer a greater resistance 

 to the effects of the anesthetic. It sometimes happened that 

 after the administration of an anesthetic the large contractions ot 

 the middle part of the ureter disappeared while the superimposed 

 undulations persisted. The same sometimes occurred after pro- 

 longed experimentation. The small and frequent undulations are 

 apparently more resistant to fatigue, also, than the larger con- 

 tractions. 



8 (151) 



Gastric peristalsis under normal and certain experimental 



conditions. 



By JOHN AXJEB. 



[From the Rockefeller Institute for Medical Research^ 



The published observations upon gastric peristalsis in rabbits 

 all seem to show that this organ, under so-called normal condi- 

 tions, is practically inert. By means of the method to be described, 

 it will be shown that the organ mentioned, under more truly 

 normal conditions, shows active movements. The fault lay with 

 the method ; the profound inhibitory effect which opening of the 

 peritoneal cavity exercises upon some of the abdominal viscera 

 was not considered. 



But operation is by no means necessary in order to study 

 gastric motility in the rabbit. If a well-fed rabbit is stretched out 

 on its back and the hair of the epigastrium clipped, any observer 

 may see active gastric peristalsis under a closer approximation to 

 physiological conditions than the saline bath affords. Mere 

 inspection of the abdomen now shows that the stomach is far 

 from inert. A short time after preparing the animal, peristaltic 

 waves are seen coursing over the stomach from left to right, in- 

 creasing in strength as the pyloric third is approached. These 

 waves are easily registered by placing a tambour over the stomach 

 region to be studied and connecting it with a writing tambour or 

 manometer. The writing tambour registers not only the change 

 in volume of the stomach part it overlies, but also the respiration 

 of the animal ; in many cases, with delicate adjustment of the 

 writing pen, the heart beats are also marked. 



