Stannius initiated research on the physiology of the conduction system of the heart. He illustrated vagal inhibition of the heart beat and indicated the existence of the pacemaker of the heart. Stannius also showed that the apex of the heart ceases to beat rhythmically when separated physiologically by ligature or clamp from the rest of the heart, while the sinus remains unaffected. Partial translation in J. F. Fulton’s Selected readings in the history of physiology, 2nd. ed., 1966, pp. 59-60.