Knowledge of how and to what extent the sweat glands are controlled by central and peripheral nervous factors is still somewhat limited. Langley1 established the fact that sweating is controlled peripherally through the sympathetic nerves, which leave the cord at definitely localized segments. Winkler2 in 1908 produced sweating by applying stimuli to the floor of the fourth ventricle, and Karplus and Kreidl3 were able to activate the sweat glands by stimulation of the tuber cinereum. Bechterew,4 Gribojedow5 and Winkler produced it by stimulation of definite areas in the frontal lobes. It is clear, then, that sweat mechanisms are located in the spinal cord, medulla, tuber cinereum and hemispheres. The relative importance of each of these mechanisms and the rôle played by each is more difficult to determine. This problem may be approached most simply through an investigation of how the spinal mechanisms are affected by