The relationship of arterial disease to disease of the kidneys is far from accurately settled.1 As a contribution to the subject I determined, in twenty-seven cases, the size and the weight of the kidneys and the ratio of the wall to the lumen of the renal arterioles in relation to histologic renal changes. So far as I know, this is the largest series of cases in which both a clinical diagnosis of malignant hypertension and a histologic study of the tissue obtained at necropsy have been made.
Consciously, or without elaborately detailed distinction, most physicians have considered various grades of severity in cases of arterial hypertension. Perhaps Volhard and Fahr,2 in 1914, were most definite in this regard. For them there was a bösartige type distinct from a milder one. Later Fahr3 used the term malignant nephrosclerosis to indicate the picture presented by the kidneys in a