The medulla oblongata has an important influence on the secretion of sweat. This fact was first recognized in 1878 by Adamkiewicz,1who observed perspiration of all foot pads of the cat on electrical stimulation of the medulla. The experiments of earlier physiologists indicated that the pathways for sweating undergo a crossing at the level of the medulla oblongata and then descend in the lateral columns of the spinal cord. In 1909 Karplus and Kreidl2presented experimental evidence that the oculopupillary and sweating pathways descending from the hypothalamus to the upper cervical region of the cord remain uncrossed, but that each half of the cervical portion of the cord controls the sweating of all four extremities. In a recent experimental study, Magoun, Ranson and Hetherington3found that the descending vegetative pathways from the hypothalamus pass through the mesial and lateral portions of the pontile tegmentum as well and