During the course of studies at the Regional Hospital at Fort Bragg, it was noted that approximately 10 per cent of all patients admitted for respiratory disease had exudate in the pharynx or on the tonsillar tissue. Some of these patients exhibited both clinical and bacteriologic evidence of beta-hemolytic streptococcus pharyngitis; some had beta-hemolytic streptococci in their throats but the clinical picture was not characteristic, and others had neither clinical nor laboratory evidence of beta-hemolytic streptococcus infection. These findings were at variance with commonly held beliefs that the beta-hemolytic streptococcus is the commonest cause of exudative pharyngitis and tonsillitis and that a characteristic clinical picture is associated with the presence of exudate in the throat.1It therefore seemed of importance to undertake a systematic clinical and laboratory study of the problem. Since beta-hemolytic streptococci may be harbored in the throats of healthy persons as well as in those suffering