1. Posterior hypothalamic stimulation produced evident decrease in the volume of gastric juice secreted; when amygdaloid complex is stimulated there are no volume variations. The stimulation with histamine produced increase in volume of juice secreted; on the other hand adrenaline did not change it. 2. It was proved that posterior hypothalamic stimulation after bilateral vagotomy enhances the gastric secretion of pepsinogen. Stimulation of the amygdaloid complex under the same conditions produced increase of pepsinogen secretion only during the post-stimulation period. 3. The post-stimulation increment of gastric pepsinogen is higher in porterior hypothalamic stimulation than in amygdaloid complex excitation. 4. Histamine and adrenaline both caused increase in gastric pepsinogen secretion. 5. Posterior hypothalamic stimulation produced a decrease in gastric juice acidity. Amygdaloid complex excitation on the other hand is without effect. During both posterior hypothalamic and amygdaloid complex post-stimulation period there appeared an increment in gastric acidity secretion. The stimulation with histamine and adrenaline is followed by a progresive increase in gastric acidity.