Influenzal meningitis, on account of its rarity, has attracted little attention in medicine. However, as the condition is becoming better known, and especially since improved diagnostic methods have come into more general use, the number of cases reported from various countries is increasing each year and evidently they will soon cease to be uncommon. There has been a wide difference of opinion in regard to the significance of B. influenzœ in infections, especially in ordinary influenza or "grippe." This is chiefly due to the fact that epidemics occur which in their clinical features are practically identical, but which appear to be caused by a variety of organisms in the respiratory tract. Whatever may be the outcome of this controversy, the occurrence of influenza bacilli in pure culture in cases of meningitis demonstrates conclusively that this organism may be highly pathogenic and therefore its presence in throats, sputa, etc., should not