Meningitis produced by B. influenzae, although not extremely common, occurs frequently enough to be of considerable interest. According to Dunn1 and Neal2 it ranks fourth in order among the types of purulent meningitis, as shown in Table 1.
In Baltimore, since 1913, at least twenty-three patients with influenzal meningitis have been seen, twenty of whom were on Dr. Howland's service in the Harriet Lane Home. Many of these cases were observed by me and I have already described3 the biologic and serologic reactions of influenza bacilli producing meningitis. It seemed advisable to report the twenty-three cases, review the literature and try to correlate the available facts about this disease which has caused so much discussion since its recognition.
The cases reported in this paper are summarized in Table 2.
Table 3 contains a list of most of the authentic cases of influenzal meningitis on record. A number