28 



Wc liave a.^ked ourselves: Where iu the kidneys do the vas- 

 cular thrombotic processes begin and how do they spread? We 

 are unable to give an entirely satisfactory answer to this ques- 

 tion. It is evident that the glomerular capillaries and the afferent 

 and efferent vessels are most generally and most profoundly 

 involved, but even where we find in these sets of vessels only a 

 very moderate involvement, we also find at least some fibrin oblitera- 

 tion in the capillaries of the tubuli eontorti, which are the branches 

 of the vasa eft'ereutia. It ap])ears quite probable that the process 

 begins in the glomerular capillaries and spreads simultaneously 

 along the afferent and efferent tracts, reaching the interlobular 

 arteries of the former and the vasa recta spuriae of the latter. In 

 both mild and severe cases of renal thrombosis some thrombi are 

 also found in the medulla and in the medullary rays, in places 

 quite remote from the glomeruli. Here there proljably occur some 

 foci of the thromboses, which arise independently of the earliest 

 ones in the glomerular capillaries. We are firmly of the opinion 

 that the formation of the renal hyaline thrombi occurs independ- 

 ently of the presence of the plague bacillus and that it is due to 

 toxines of this micro-organism circulating in the blood, but exactly 

 how these toxines give rise to the thromlms formation is a question 

 which we are at present unable to answer. Very probably they may 

 have a deleterious influence upon the vascular endothelium, but 

 certainly they do not ordinarily produce a manifest, demonstrable 

 morphologic change either in the intima or in the renal vessel walls 

 in general. 



According to the intensity of the process, the 12 cases in which 

 thrombosis in the renal vessels was encountered may be divided 

 into three groups, viz : 



Thrombosis of a moderate degree: Cases Nos. 11 (1113) . 11: 

 (928), 17 (1011), 23 (973), 30 (983)— 5 cases. 



Thrombosis of a higher degree: Cases Nos. 2 (989), 13 (1183), 

 16, 31 (1082)—! cases. 



Thrombosis of a very high degree: Cases Nos. 15 (910), 18 

 (1127), 20 (1157)— 3 cases. 



Extensive and frequently occurring hyaline fibrin throml)Osis of 

 the glomerular capillaries and of the other renal vessels has not 

 often l)een found in human infectious diseases, at least not in a 

 high percentage of the larger series of cases examined, and in 

 animal diseases only in the example cited by Welch (swine plague). 



