The character of the periodic and continuous motor activity of the empty stomach in man and other animals has been described. It has also been shown that the contractions of the empty stomach give rise to the sensation of hunger or the "hunger pangs" by | stimulation of afferent nerve-endings in the gastric mucosa. We have also seen that in man the hunger contractions of the stomach are inhibited, reflexly, by all stimuli acting on end organs of taste and general sensations in the mouth cavity, so that in case of chewing palatable foods when in hunger we have the so-called psychic secretion of gastric juice preceded and paralleled by a psychic inhibition of gastric motility and tonus. It has also been shown that the hunger contractions persist in their essential character after section of the nerves connecting the stomach with the central nervous system. If we are to attempt to determine more specifically the cause of the hunger contractions our attention must be directed to the stomach itself. The contractions of the empty stomach may be due to any one of these four conditions.