THE URINAEY TRACT. 757 



drawn nowadays from the presence of such micrococci in certain forms of 

 nephritis cannot be regarded justifiable, I am satisfied with the statement of 

 the above condition. The majority of the glomeruli are moderately enlarged 

 and their vessels provided with more abundant bodies resembling nuclei 

 than normal ; I cannot decide whether these changes proceeded from the inter- 

 vascular connective tissue (Axel Key) or from the epithelial covering. The 

 connective tissue around the glomeruli and between the urinary tubules is 

 everywhere enlarged, more markedly in the cortical than in the pyramidal 

 substance. In the dilated interstices we meet with separated bundles of con- 

 nective tissue, a condition which corresponds to serous infiltration or oedema 

 of the connective tissue. At intervals clusters of red blood-corpuscles are 

 found in the oadematous connective tissue. In some places the connective 

 tissue is granular and abundantly provided with nuclear formations, which is 

 the beginning of interstitial infiltration. The epithelium of the convoluted 

 as well as of the straight, urinary tubules is swollen throughout. Many of the 

 convoluted tubules are enlarged and irregularly sinuous, and their central 

 caliber is reduced to a minimum. In a number of narrow tubules the caliber 

 has entirely disappeared. 



The epithelia, especially those of the convoluted tubules, are filled with 

 coarse granules, mostly to such an extent that the nucleus is concealed. This 

 condition, known as " cloudy swelling," is mentioned by all authors, but its 

 nature was unknown. In the acute stage of inflammation we have not to deal 

 with fat granules, which may be proved by simple tests. With high magnify- 

 ing powers we see that a large majority of the granules within the epithelia are 

 united by fine threads, and such threads we recognize also in the perinuclear 

 rim, wherever the nucleus is visible. Cloudy swelling, therefore, is produced 

 by a growth of the living matter in the epithelia. As I propose to show later, 

 we have here the first steps toward an endogenous production of new ele- 

 ments. 



. If the acute catarrhal inflammation from its beginning is not severe enough 

 to cause the death of the individual ; if, furthermore, it does not affect the 

 entire kidney, but only disseminated foci, either the desquamative or the 

 interstitial form of inflammation is more prominent. I had the opportunity 

 of studying these forms in kidneys of persons who died of tuberculosis, in 

 whom this nephritis is of almost invariable occurrence. (See Fig. 341.) 



The calibers of the capillaries are mostly preserved ; their walls, however, 

 appear reduced to elements analogous to those which fill the surrounding 

 connective tissue. The glomeruli are moderately enlarged and their vascular 

 loops concealed by abundant, shining, nuclear formations. They present the 

 appearance which Klebs described as " glomerulo-nephritis," a superfluous 

 name in the face of the fact that inflammatory changes of the glomeruli 

 merely accompany the diffuse nephritic process. It seems that in these 

 changes the intra-capsular connective tissue is involved as well as the lining 

 epithelium. Where the tuft is separated from the capsule, or has fallen out, 

 we can convince ourselves that the epithelium of the capsule is for the most 

 part converted into homogeneous, shining lumps, or that the nuclei alone have 

 undergone this change. 



The connective tissue between the urinary tubules is widened. Its fibrous 

 structure is retained only in part, while its greatest portion is converted into 

 variously shaped lumps, partly granular and partly homogeneous, represent- 

 ing the so-called ' ' inflammatory infiltration." We see that the majority of the 



