Agglutinins to B. dysenteriae were present in 6.29% of 524 sera from individuals only one of whom gave a history of dysentery, 30 yrs. previously. The series consisted of an equal number of males and females. The males showed 6.1% and the females 6.48% positive. The highest titers were found in specimens from males. The males reacted most frequently to Sonne''s bacillus but the highest titers were to Types V, W, and Z of the Flexner group. The females reacted most frequently to Type V Flexner. The presence of these "normal agglutinins" may interfere with serolog-ical diagnosis, as they sometimes come within the range of the standards laid down as indicative of active infection; besides, in active infections agglutinins may not always reach these suggested standards. There is sufficient evidence to suggest that these so-called normal agglutinins are the outcome of subliminal or mild infection with homologous or associated micro-organisms, and that the term "normal" when applied to this reaction is a misnomer and should be avoided.