The name "Pfeiffer bacillus meningitis" may be misleading. The strain found in the cerebrospinal fluid and in pus from the ankle-joint of a baby was reported by Dr. Edith Straker, London School of Hygiene, to be antigenic Type B (Pittman), the type most often found in influenzal meningitis in infants. Although a late and insufficient dosage of sulfapyridine failed to save the child''s life the temporary clinical improvement, de- creased pressure in the C.S.F., and reduced number of organisms in direct smears of the C.S.F., warrant further trials of the drug.