Ever since Mönckeberg's1 investigation of the myocardium and bundle of His in connection with cases of death in diphtheria, it has been known that the effect of diphtheria toxin on the auriculoventricular bundle has not been a selective one, and that this special structure of the heart tissue undergoes pathologic changes in this disease quite similar in character to that of the rest of the myocardium. These and other investigations of the heart in diphtheria have often been conducted on

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... dying of the disease, who during life did not necessarilly show symptoms typical of cardiac failure or of heart-block. Tanaka2 examined fifteen hearts of children dying during the course of or after diphtheria. He found that the acute cardiac weakness was due to general myocardial changes without involvement of the auriculoventricular bundle, and he concludes that the changes in the latter tissue can seldom be regarded as the cause of death. Fatty degeneration and a "waxy-like" degeneration of the muscle fibers consisting of loss of cross striations with a partial or com¬ plete loss of nuclear staining, were found as the chief changes in the His bundle. Rohmer,3 in particular, has taken up recently the study of heart disease in children with special reference to the involvement of the auriculoventricular bundle. His investigations clinically were supported with observations on the heart by means of the electrocardiogram, and for this reason the anatomical findings in cases of heart-block described by him as appearing between two and three days before death, are impor¬ tant and a distinct contribution to this subject. The His bundle from Tawara's node to a point beyond the division into the right and the 1. M\l=o"\nckeberg,J. G.