774 



THE URINARY TRACT. 



tubule, where it must have originated. The same may be said of casts found in 

 tubules entirely stripped of epithelia, whose calibers are broader than the 

 diameters of the casts. It cannot be denied that a mass closely resembling 

 a hyaline cast may be produced from endothelia ; for I have seen such irregu- 

 lar formations lying along the border of a tubule bounded toward the center 

 of the caliber by a row of epithelia, which had been detached by the exudate 

 and undergone no change. Formations of this kind are, however, very 

 exceptional. 



In chronic croupous nephritis granular casts are commonly found to be 

 more abundant than other varieties, the granules being probably due to a dis- 

 integration of the ensheathing endothelia. Fatty and waxy casts are also 



FIG. 351. HYPERTROPHY OF KIDNEY, AFTER CROUPOUS 

 NEPHRITIS. 



C, granular cast, holding in its center waxy lumps ; E, emlothelial lining of the tubule 

 around the cast ; T, empty tubule ; 7, interstitial connective tissue, with injected blood- 

 vessels, holding a moderate number of inflammatory corpuscles. Magnified 600 diameters. 



features of this form of nephritis; these always indicate a similar meta- 

 morphosis in the kidn'ey-tissue itself. 



(3) In chronic suppurative nephritis abscesses formed in the kidney may 

 exceptionally lead to the production of a dense connective-tissue capsule the 

 "pyogenous membrane" of writers and pus, under these conditions, be- 

 comes inspissated into a cheesy mass, which, by some, has been mistaken for 

 tubercle. 



A formation of this kind may be termed a chronic abscess of the kidney, 



