140 JoCR.XAL OF TllK M ITC II KLI, SoCIKTV [DeC. 



cells either greatly encroach upon or occlude the lumen of 

 the tubules. The vacuolation usually first appears in the 

 zone just around the nucleus and later not infrciiucntly takes 

 the place of the nucleus. The vacuoles are not fatty in na- 

 ture. These are the initial changes. The epithelium of the 

 tubules deep in the cortex and of the convoluted tubules un- 

 dergoes a rapid necrosis. The swelling and necrosis may be 

 of a most severe grade (fig. 2), and involve all of tlic tubules 

 of the labyrinth excepting the junctional and collecting tu- 

 bules. These tubules are not usually involved in the ne- 

 crotic process. 



1-lG. 4 



Figure 4 represents the kidney of an animal nephritic from uranium 

 nitrate. The nephrotoxic substance was given in tlie usual dose of 6.7 

 mgs. on two successive days. The kidney was removed under light 

 ether anesthesia. The animal was freely diuretic. The epithelium is 

 not necrotic. The lumen of the tubules have not been encroached upon 

 b}' any marked swelling of the epithelium. 



The above mentioned changes are remarkable not only 

 on account of their wide spread nature and severity, but on 

 account of the rapidity with which they develop. 



The tubules of the loop of Uonle contain large amounts 



