There appeared in an earlier issue of the American Journal of Cancer,1 an article by Dr. Wm. C. MacCarty, showing that the size of operable cancers has not decreased during the past fifteen years. When we were interested in publicity campaigns, we had certain opportunities for estimating the results of popular education for the control of cancer. These left some definite impressions. (1) As regards cancer, the potential field is so great that it will take considerable effort to show improvement statistically. In Detroit, in 1928, 20 per cent of a consecutive series of patients dying from cancer of the cervix died without having had operation or radiation, 22.6 per cent of breast cancer patients who died had had no operation, while 40 per cent of those dying of stomach cancers had never been in a hospital for their final illness. This last corresponds with Dr. MacCarty's statement that “not over 25 per cent of the gastric and large intestinal cancers have been previously examined by x-ray.” It seemed that this large and untreated reserve, together with the larger number of late cases, and the so-called “apparent” increase in the disease, would for a long time be a deep pool which would dilute any local or even general efforts at earlier apprehension of the disease. Though valuable, the results of such efforts would represent only a skimming of the surface of the pool, which would then be rapidly filled up again from these sources. (2) The inherent difficulties in popular education against cancer are great.