THE ACTION OF THE SYMPATHETIC UPON THE EXCITATORY PROCESS IN THE MAMMALIAN HEART.

Stimulation of the sympathetic nerve endings, after paralysis of the vagus, accelerates the transmission of the excitatory process in the dog's auricle. Following the functional exclusion of the vagus ergotamine slows the rate of the sinus rhythm, depresses A-V conduction, and delays the transmission of the excitatory process in the auricle. The relation of the sympathetic and parasympathetic nerves in the control of the cardiac rhythm is discussed.