Attempts to produce gastric carcinoma experimentally in a gastric ulcer.

rrhe marked resistance of the glandular stomach of animals to spontaneously occurring cancer is well known. A similar resistance to the experi mental production of cancer has been observed, since carcinogenic agents have been fed to mice and rats without producing cancer of the glandular stomach (6) . However, when threads saturated with methylcholanthrene were imbedded in the mucosa of the stomach of mice, a cancer developed (6). In view of these results it has been postulated that the gastric mucus or the superficial gastric mucous cells may serve as a barrier to carcinogens in the diet (4). In order to avoid this possibility, it was decided to produce a chronic ulcer of the glan dular stomach of an animal so that the orally ad ministered carcinogen might come into contact with the proliferating cells in the margin of the ulcer (.5).