I. The gastric mucosa of the cat -- II. The gastric mucoid cells of foetal and newborn animals -- III. The gastric mucoid cells in man, dog, rabbit and frog -- IV. The question of a gastric hormone -- V. The source of the proteolytic enzyme in extracts of the pyloric mucous membrane -- VI. A new method for obtaining a pure pyloric secretion -- VII. General conclusions regarding the functions of the gastric mucoid cells.