62 (i 26) Society for Experimental Biology and Medicine. 



to the cannula. In one animal, anesthetized with cocain by the 

 lumbar puncture method, the same results as with morphin were 

 obtained. In two artificially constructed systems, which were 

 demonstrated, phenomena analogous to those observed in the 

 animals were produced and the causes indicated. 



The experiments, which also were demonstrated in part, seem 

 to justify the following deductions : 



1. A suction normally follows the peristaltic wave of the 

 ureter ; at the same time a force is exerted on the fluid in front 

 of the wave. 



2. When the ureter is normally acting, the pressure in the 

 pelvis of the kidney remains very low, fluctuating about a neutral 

 point, this condition obtaining through the anatomical arrangement 

 of the pelvis, which prevents it from collapsing under negative 

 pressure. The rhythmic movements of the pelvis of the ureter 

 effect a milking of the portion of the pyramid which projects into it. 



3. Under the influence of chloroform, or conditions which retard 

 muscular tone and activity, the pressure in the ureter becomes 

 greater than that prevailing in the bladder. 



4. It seems obvious, then, that the ureter functions as an active 

 agent in the formation of urine. Sollmann has shown in his per- 

 fusion experiments on excised kidneys that the formation of urine 

 is largely, though of course, by no means wholly a filtration 

 process. 



5. Ether anesthesia does not cause a cessation of the peristaltic 

 movements of the ureter, but because of its suppressing action on 

 the urinary secretion the curves were not recorded. 



6. The ureter remains rhythmically contractile when excised 

 and. placed in warm physiological salt solution, or for some time 

 after the death of the animal when left in situ. Therefore contrac- 

 tility is not dependent on pressure. 



7. An increased flow of urine calls forth a more efficient peri- 

 stalsis, and therefore does not result in an increased pressure. 



8. The force of the peristaltic wave was seen to raise a column 

 of water of considerable height. 



9. When sufficient force is exerted by the intrinsic pressure to 

 overcome the peristaltic contractions the urine is forced back into 

 the urinifcrous tubules and accurate communication is attained 



