THE great radiologist whom we commemorate this evening was profoundly interested in the diagnosis of gastric cancer. He made substantial contributions to the science and art of its diagnosis. His criteria for the radiologic identification of gastric cancer, as set forth in his book, are widely followed to-day. He was a victim of the disease and himself made the diagnosis under dramatic circumstances. For these reasons I have deemed the topic appropriate for this occasion. Although the radiology of the alimentary canal actually began in America with Bowditch's suggestion to Cannon, which resulted in the latter's notable researches on animals, and with the examination of a child's stomach by Williams and Cannon, the capabilities of the new method were not appreciated in this country and the next steps in advance were made by Europeans, but only after many years. When Carman came to Rochester, in 1913, he knew relatively little about gastro-intestinal radiology. When he walked out of the screen room for the last time, now nine years ago, he was undoubtedly one of the ablest radiologic diagnosticians of gastric and duodenal disease in the world. How did he acquire this knowledge and skill? Not by sparkling brilliance of mind or effortless inspiration, but by hard work, well applied. Carman's mental processes were simple, direct, almost invariably accurate, and, above all, thorough. He thought his problems through. From the older radiologists Carman received less of instruction than of stimulation. He respected their dicta, but never accepted them fully until he had proved them by personal observation. So, at the Mayo Clinic, Carman consistently followed his cases to the operating room, the necropsy table, or the pathologic laboratory. Thus all that Carman knew, which was much, he learned at first hand and knew beyond all shadow of doubt. He knew the morbid anatomy of gastroduodenal disease in relation to its radiologic manifestations as few other men have ever known it. His mental picture of gastric cancer, for example, was not derived merely from drawings, or from photographs or lantern slides, but from its varied radiologic images, its appearance when the abdomen was opened, its gross aspects after removal, and its histologic structure as revealed by the microscope, all of which he synthesized into a coherent and practical conception of the disease. Thus Carman not only taught by trustworthy precept but set an example which may well be followed by all radiologic diagnosticians. Morbid Anatomy Every radiologist knows, but he sometimes fails to realize thoroughly, that cancer may take the form of a frank tumor, an infiltration, or an ulcer without evident tumefaction. He is aware, too, that not all cancers are extensive when discovered, and that often they are demonstrable when exceedingly small. He knows, further, that although cancer has a preference for certain segments of the stomach, it may affect any part of the viscus. But circumstances impel him to keep much of this knowledge in latent form, and to think idly of cancer as a massive tumor, typical in situation and deforming the barium shadow so grossly and so characteristically that the disease can scarcely escape recognition.