In the submaxillary gland (SG) of the cat, physostigmine increases the secretory and vasodilator response on stimulation of the chorda tympani nerve without affecting the results of stimulation of the cervical sympathetic trunk. Cocaine increases the secretory and constrictor action resulting from the stimulation of the cervical sympathetic without influencing the chorda response. Stimulation of the cervical sympathetic nerve, after destroying all branches except those going to the SG, contracts the denervated nictitating membrane on the opposite side (especially in presence of cocaine), provided the return circulation from the stimulated gland is intact. Stimulation of the sympathetic fibers to the SG may cause a slight general vasoconstriction, indicated by a rise in arterial pressure and a decreased blood flow in the opposite denervated gland. These results indicate the elaboration in the SG, in response to sympathetic nerve stimulation, of a chemical agent with adrenergic properties and con-trasting with the cholinergic agent liberated on stimulation of the parasympathetic fibers.