IN the course of an investigation of the hospital population to determine possible sources of staphylococcic infections 100 consecutive twenty-four-hour sputum specimens that had been sent to the laboratory to be examined for tubercle bacilli were also examined by culture for the presence of staphylococci. Staphylococcus aureus was found to be present in 29 of the 100. Bacteriophage typing was possible in 25 whereas the strains present in 4 were nontypable. Bacteriophage types encountered consisted of 3-A, 3-B, 3-C, VA-4, 6, 7, 29, 42-B, 42-D, 42-E, 44-A, 47, 52, 53, 54, 55, 75, 77, 79, 80 and 81. The number . . .