Although there is still a great difference of opinion regarding the usual mode of infection in bacillary disease of the urinary tract, it is generally admitted that infection of the pelvis and of the renal parenchyma does occur by the ascending route. In many instances the process is aided by obstruction in some portion of the urinary tract. A vast amount of experimental work has been done in tracing the infection from the bladder to the renal pelvis, and it has been shown that it can travel up the periureteral lymphatic structures and that infection of the pelvis can come from the bladder by way of the lumen of the ureter without any evidence of involvement of the ureteral wall.
I shall not consider the mode of infection of the renal pelvis. It is my object to show that stasis in the urinary passages is the determining factor in the