Notwithstanding years of intensive clinical study of the etiology, pathology, course and effects of treatment of chronic peptic ulcer, many points are still open for discussion. The advent of roentgenography has given a renewed impetus, opening up afresh, as moot questions, problems that apparently had been satisfactorily answered. The recent contributions of roentgenologists have tended to show that under favorable circumstances many ulcers tend to disappear and presumably to heal, the disappearance of the roentgenographic niche being the criterion on which such a judgment is founded. On the other hand, the operation of subtotal gastrectomy for the radical removal of ulcer, an operation that seems likely to enjoy an increasing and a well warranted sphere of activity, has delivered into our hands fresh ulcer specimens of various types and at various stages in the life cycle of the peptic process. These two factors alone have contributed considerable new information concerning