To the Editor: Dr. J. J. Reedy recently reported, in the Journal of Heredity (48:37–44, 1957), the results of a study of 50 pedigrees whose propositi were patients with paralytic poliomyelitis. His careful investigation revealed that in 5612 relatives of these patients 38 cases of paralytic poliomyelitis had occurred within the previous five-year period, giving a rate of 6.75 per 1000. This rate was contrasted with one of "less than 2 per thousand" in the general population in the area sampled (a radius of 100 miles about South Bend, Indiana). The conclusion was drawn that this difference was consistent with . . .