════════╤═════════════════╤═════════════════ │ │ │ STAPHYLOCOCCI │ B. INFLUENZÆ ────────┼────────┬────────┼────────┬──────── │ NO. │PER CENT│ NO. │PER CENT │POSITIVE│POSITIVE│POSITIVE│POSITIVE ────────┼────────┼────────┼────────┼──────── Bronchus│ 61│ 50.4│ 96│ 79.3 Lung │ 37│ 24.2│ 70│ 45.7 Blood │ 1│ 0.5│ 1│ 0.5 ────────┴────────┴────────┴────────┴──────── Cultures from the bronchus represent the bacteriology of the bronchitis of influenza. Infection of the lung following influenza doubtless occurs by way of the bronchi, so that the bacteria which cause pneumonia are present in the bronchi before they enter the lung tissue. The figures in Table XXVIII, similar to those previously cited, show the high incidence of B. influenzæ, and the occurrence of pneumococci, hemolytic streptococci and staphylococci each present in approximately half of all autopsies. The figures in Table XXVIII are an index of the capacity of the microorganisms which enter the bronchi to invade the lungs and finally the blood. Pneumococci were present in the bronchi in 46.3 per cent of instances, in the lungs in only slightly less, and in approximately 40 per cent of autopsies they had penetrated into the blood. Hemolytic streptococci enter the bronchi with the same frequency and exhibit an equal ability to penetrate into the lungs and blood. Staphylococci enter the bronchi in half of these individuals, but penetrate into the lungs in only a fourth of the instances. They have entered the blood only once (Autopsy 263) in this instance in association with hemolytic streptococci. B. influenzæ has been present in the bronchi in approximately 80 per cent of autopsies. It is noteworthy that it has been found in the lung in little more than half this percentage of instances and has entered the blood only once (Autopsy 474), in this instance in association with hemolytic streptococci. In a limited number of autopsies there was purulent bronchitis recognized by the presence of mucopurulent exudate in small bronchi. It has been stated that this group of cases is not sharply separable from other instances of bronchitis, because in some cases death has occurred before a purulent exudate has accumulated or in other instances a purulent exudate has been displaced by edema. Table XXIX shows the bacteriology of instances of purulent bronchitis: TABLE XXIX