The facts collected in the third part of this paper justify the following conclusions:
(1) All of the cardinal symptoms of Stokes-Adams disease may be duplicated by heart-block resulting from a lesion in or near the auriculo-ventricular bundle of His, and by this alone.
(2) No typical case of Stokes-Adams disease has been described in which heart-block might not have been the cause of the trouble.
(3) It can be shown that all cases of Stokes-Adams disease which have been studied by sufficiently accurate methods were cases of heart-block.
(4) It would appear that heart-block without and with syncopal attacks are two stages of the same disease process.