THE URINARY TRACT. 



Ill 



cles takes place, encroaching upon the caliber, rendering it irregular, as if 

 compressed. Often, however, the narrowed lumen contains a finely granular 

 or homogeneous mass, probably plasma of the blood. The spindles of the 

 smooth muscle-fibers of the middle coat are transformed into inflammatory 

 corpuscles. These bodies, at first, are not numerous, but, in more advanced 

 stages, appear to compose the entire tissue, which still preserves a resem- 

 blance to the original smooth muscle -structure. These characteristics 'are 

 particularly well marked in transverse sections, where a decided increase in 

 the circumference of the vessels is also noticed. Similar changes take place 

 in the external coat, till finally the entire arterial wall is converted into a 

 solid connective-tissue cord, which may, in places, still show faint traces of 

 the former caliber. Cords of this kind, as a general thing, present the feat- 

 ures of waxy degeneration. 



(2) Chronic Croupous Nephritis. The clinical features of this form of 

 nephritis are somewhat different from those attending cirrhosis. 



FIG. 349. CIRRHOSIS OF KIDNEY. INFLAMMATION OF AN ARTERY. 



E, endothelia in active proliferation, the caliber considerably narrowed ; M, middle coat, 

 the smooth muscles in part transformed into rows of inflammatory corpuscles; A, adventitial 

 coat, crowded with inflammatory corpuscles, partly sprung from the capillaries of the adven- 

 titia. Magnified 600 diameters. 



In chronic croupous nephritis symptoms of uraemia are more common than 

 in the cirrhotic form, and sudden death is much more frequent. The urine 

 invariably contains casts and albumen ; the former are usually granular, and 

 waxy or fatty if the corresponding changes have taken place in the diseased 

 kidney. Hyaline, epithelial, and blood casts may also appear in addition to 

 those first enumerated, if an acute attack of inflammation is superadded to 



