The relative frequency with which different types of pneumococci produce lobar pneumonia under the conditions existing when Camp Pike was attacked by an epidemic of influenza is indicated by Table XXXII in which instances of lobar pneumonia alone and of combined lobar and bronchopneumonia are listed separately. Pneumococcus I and II, which are found approximately in two-thirds of instances of lobar pneumonia occurring in cities, have an insignificant part in the production of these lesions. Pneumococcus IV and atypical Pneumococcus II, which are commonly found in the mouth, are the predominant cause of these lesions, and with Pneumococcus III, also an inhabitant of the mouths of normal individuals, have been the cause of two-thirds of all instances of lobar pneumonia observed in this camp. TABLE XXXII WITH LOBAR PNEUMONIA ════════╤════════╤═════════════════╤═════════════════╤═════════════════ │ NO. OF │ │ │ PNEUMOCOCCUS II │CULTURES│ PNEUMOCOCCUS I │ PNEUMOCOCCUS II │ (Atyp.) ────────┼────────┼────────┬────────┼────────┬────────┼────────┬──────── │ │ NO. │PER CENT│ NO. │PER CENT│ NO. │PER CENT │ │POSITIVE│POSITIVE│POSITIVE│POSITIVE│POSITIVE│POSITIVE ────────┼────────┼────────┼────────┼────────┼────────┼────────┼──────── Bronchus│ 30│ 1│ 3.3│ 1│ 3.3│ 4│ 13.3 Lung │ 34│ 1│ 2.9│ 2│ 5.9│ 9│ 26.5 Blood │ 54│ 2│ 3.7│ 2│ 3.7│ 12│ 22.2 ────────┴────────┴────────┴────────┴────────┴────────┴────────┴──────── ════════╤═════════════════╤═════════════════ │ │ │PNEUMOCOCCUS III │ PNEUMOCOCCUS IV ────────┼────────┬────────┼────────┬──────── │ NO. │PER CENT│ NO. │PER CENT │POSITIVE│POSITIVE│POSITIVE│POSITIVE ────────┼────────┼────────┼────────┼──────── Bronchus│ 4│ 13.3│ 10│ 33.3 Lung │ 6│ 17.6│ 11│ 32.4 Blood │ 3│ 5.6│ 17│ 31.5 ────────┴────────┴────────┴────────┴──────── WITH COMBINED LOBAR AND BRONCHOPNEUMONIA