Summary of the results obtained in normal men shows that the incidence of B. influenzæ in normal individuals from isolated communities or in groups free from respiratory diseases prior to the occurrence of the fall epidemic was relatively low, namely, 10 to 20 per cent; that in observations made before the fall epidemic in groups in which “bronchitis” and pneumonia were fairly prevalent, B. influenzæ was found much more frequently, namely, in 25 to 50 per cent of the cases; and that in groups studied at intervals during the epidemic the incidence of B. influenzæ rapidly rose, reaching 85 per cent at the end of the epidemic. In contrast with this, B. influenzæ was found in 100 per cent of cases of influenza without reference to the time at which they occurred during the epidemic. It is obvious that the high percentage of normal men carrying B. influenzæ found at the end of the epidemic can depend only on the wide dissemination of B. influenzæ that must occur during epidemic times. =Bacillus Influenzæ in Measles.=—Since the presence of B. influenzæ in other diseases than influenza has been advanced as an argument against its causal relationship to influenza, an extensive study of the incidence of B. influenzæ in the throats of measles patients was made during the period of the epidemic of influenza at Camp Pike from September 10 to October 20. In all a total of 830 throat cultures in 487 cases of measles were made, many cases being cultured repeatedly at weekly intervals. The results have been condensed as far as possible and are presented in Tables X, XI, XII. TABLE X INCIDENCE OF B. INFLUENZÆ IN 400 CONSECUTIVE CASES OF MEASLES AS DETERMINED BY THROAT CULTURE AT TIME OF ADMISSION TO THE BASE HOSPITAL ═════════════════╤═════════════════╤═══════════════════════════════════ DATE │ NUMBER OF CASES │ B. INFLUENZA FOUND ─────────────────┼─────────────────┼─────────────────┬───────────────── „ │ „ │ NUMBER │ PER CENT ─────────────────┼─────────────────┼─────────────────┼───────────────── Sept. 16–Oct. 4 │ 100│ 27│ 27 Oct. 4–Oct. 10 │ 100│ 32│ 32 Oct. 10–Oct. 15 │ 100│ 32│ 32 Oct. 15–Oct. 19 │ 100│ 48│ 48 ─────────────────┴─────────────────┴─────────────────┴───────────────── The prevalence of B. influenzæ in cases of measles during the period of the influenza epidemic corresponded very closely with that found in normal individuals under similar circumstances. The increasing proportion of cases carrying B. influenzæ as the epidemic of influenza advanced is further evidence of the wide dissemination of the organism during the epidemic. TABLE XI