The type incidence of pneumococcus infections in the St. Louis metropolitan area observed during the winter of 1938-39 showed Type I infections 20.3%; Type III, 10.8%; Type V, 8.5%; Type VII, 7.4%; Type VIII, 6.8%; Type VI, 6%; and Type XIX, 4.5%. The individual higher types occurred in an incidence of less than 2%. 126 cases of Types I, II, V, VII, VIII, and XIV treated with type-specific rabbit serum gave a gross mortality rate of 7.9%; 143 cases, including 25 cases of Type III pneumonia, treated with sulfapyridine gave a gross mortality rate of 9.09%. The 2 series are analyzed as to age incidence, day of disease when first treated, and other factors.