The histological structure of the intestinal glands of Lumbricus is described, and their subjection to nervous regulation is demonstrated. The presence of a protease in the juice of the anterior intestine, described by previous workers, is confirmed, and the existence of nerve elements exciting the secretion of protease is demonstrated in the segmental nerves, body wall and ventral regions of the septa in the anterior intestinal region. The pathway of impulses which excite the secretion of protease is deduced. The distribution of nerves which excite secretion of protease in the anterior intestine is compared with that of the nerves which influence the tone of the gut. The significance of the nervous control of the secretion of intestinal protease in Lumbricus is discussed in relation to the factors known to influence secretion in vertebrates.