Scientific Proceedings. 



7 



For the last two years I have been engaged in experimental 

 studies of the ureter, which were carried out in the laboratory of 

 biological chemistry at the College of Physicians and Surgeons. 

 Some of the results of that work I had the honor to present at a 

 meeting of this Society in April, 1905. 1 During the past summer 

 I have studied the course of the normal peristalsis of the ureter 

 (of the dog) at the Rockefeller Institute, under the direction of 

 Dr. S. J. Meltzer. 



The results that I wish to report here very briefly are as 

 follows : 



In dogs narcotized with morphin the peristaltic contractions of 

 the middle part of the ureter occur at intervals varying between 

 6 and 15 seconds. The curves representing these contractions 

 are of variable but generally of fairly good size. The duration of 

 such a contraction may vary from 5 to 1 5 seconds. The variations 

 of the size and duration of these peristaltic contractions depend 

 upon the size of the animal, the amount of secretion of urine, and 

 many other conditions which I shall not attempt to discuss here. 

 But for the same animal and under the same conditions the char- 

 acters of the peristaltic contractions remain in general the same for 

 nearly the entire length of the experiment, which sometimes con- 

 tinued about 5 or 6 hours. 



These peristaltic contractions are apparently those which 

 Engelmann and other writers had under observation. I found 

 however, that the renal pelvis as well as the uppermost part of the 

 ureter exhibits peristaltic contractions of another kind ; they are 

 small, of short duration and occur as frequently as every 2 or 3 

 seconds. 



In some animals, in which the contractions from the middle 

 part of the ureter presented fairly large curves, it frequently hap- 

 pened that these curves were superimposed by finer undulations. 



From the lower end of the ureter only a few tracings were 

 obtained. Judging from this restricted experience it would seem 

 that in the lower end also the small and more frequent contractions 

 predominate. 



Anesthetics, e. g. y chloroform or ether, exercise pronounced 

 effects upon the peristaltic movements of the ureter. The small 



1 Proceedings of this Society ; 1 904^05, ii, p. 61. 



