=Bacillus Influenzæ in Cases of Influenza.=—On October 10, 1918, at the height of the epidemic at Camp Pike, search for B. influenzæ was made in a group of 23 consecutive cases of uncomplicated influenza from one to six days after the onset of the disease. From each individual simultaneous cultures on blood agar plates were made (a) from the nose, (b) from the throat, and (c) from the sputum, and the sputum from each case was injected into the peritoneal cavity of a white mouse. A similar study of 5 consecutive cases was made on November 19. The results are presented in Table II. By means of multiple cultures taken simultaneously from different portions of the respiratory tract no difficulty was encountered in demonstrating B. influenzæ in all these cases of uncomplicated influenza. Not only was B. influenzæ found in all cases, but often in very large numbers predominating over all other bacteria on at least one of the plates from each patient, and in occasional instances occurring in nearly pure culture. One culture made about two hours after onset of the initial coryza is of interest. There was at the time a profuse serous nasal discharge. One drop of this allowed to fall on the surface of a blood agar plate gave a practically pure culture of B. influenzæ. TABLE II PRESENCE OF B. INFLUENZÆ IN 28 CASES OF INFLUENZA ═══════════╤═══════════╤═══════════╤═══════════╤═══════════╤═══════════ NO. │ DAY OF │ NOSE │ THROAT │ SPUTUM │ SPUTUM │ DISEASE │ │ │ CULTURE │ PASSED │ │ │ │ │ THROUGH │ │ │ │ │ MOUSE ───────────┼───────────┼───────────┼───────────┼───────────┼─────────── 1│ 1 │ + │ + │ + │ + 2│ 4 │ − │ + │ + │ + 3│ 5 │ − │ − │ + │ − 4│ 4 │ − │ − │ + │ + 5│ 3 │ − │ − │ + │ + 6│ 4 │ − │ + │ + │ c 7│ 2 │ − │ + │ − │ c 8│ 4 │ + │ + │ + │ − 9│ 5 │ − │ + │ + │ + 10│ 2 │ + │ − │ − │ − 11│ 2 │ − │ + │ c │ + 12│ 3 │ c │ + │ + │ + 13│ 3 │ − │ − │ − │ + 14│ 2 │ − │ − │ + │ + 15│ 3 │ c │ − │ − │ + 16│ 1 │ − │ + │ + │ + 17│ 3 │ − │ + │ − │ +