With regard to the number of cases that have been proved at operation : The cases of gastric ulcer on the lesser curvature, the greater curva¬ ture, the pylorus, the posterior wall, with the exception of the one high up on the posterior wall, and approximately SO per cent of the duodenal ulcers have been proved at operation. I have particularly made it a point to study the specimens with reference to the mucous membrane change surrounding the ulcer and comparing this with the appearance of the roentgeno¬ gram. I do not profess at all to be an expert in this type of diagnosis. After seeing the work done by Âkerlund and Berg.