That the diplococcus pneumoniæ, in common with other micro-organisms, may occasionally be found within leucocytes as the result of phagocytosis in inflammatory processes, has been frequently noted by numerous observers. Its extracellular position, however, in the exudate in cerebrospinal meningitis is so markedly the rule that the point is used as a differential characteristic between the organism and diplococcus intracellularis meningitidis. Consequently, the preponderatingly intracellular position of diplococcus pneumoniæ in the following four cases of cerebrospinal meningitis makes them of sufficient interest to warrant their record.
—In June, 1898, a specimen of cerebro-spinal fluid from a case of cerebrospinal meningitis, removed by lumbar puncture during the third week of the disease, showed in direct cover-slip preparations, numerous encapsulated, lanceolate, Gram-staining diplococci, most of which were intracellular. Cultures in broth, on plain and blood agar, and Löffler's blood serum developed, without admixture of other organisms, a diplococcus, which, despite