Efforts to produce chronic gastric or duodenal ulcers experimentally have met with indifferent success so far as any direct bearing on ulcers in the human stomach is concerned. Dogs, the experimental animals usually employed for this purpose, are notoriously immune to ulcerations of this nature, unless complex procedures are employed by which the normal physiology is so disturbed that conclusions cannot be drawn with any great accuracy. In recent years chronic experimental ulcers have been produced, notably by Dragstedt and Vaughn,¹ Hanrahan in an experimental study as yet unpublished, Mann² and his co-workers and Wolfer.³ Any bearing that these reported experimental results may have on the subject would seem to be applicable more to the postoperative ulcer than to the primary one. Wolfer's experiments in which he produced ulcerations by exposing gastric mucosa over long periods of time to the roentgen ray, though of interest, apparently do