Mutation of Cholera-Like Vibrios under the Action of Bacteriophage

Introduction.?Koch in 1883 isolated the cholera vibrio from cholera patients in Calcutta. Tinkler and Prior (1884) and Deneke (1885) described vibrios resembling Koch's vibrio that had been isolated from non-choleraic material. In the twelve years following the discovery of the cholera vibrio, Metchnikof, Sanarelli, Gunter, Foker oftid other workers isolated vibrios indistinguishable morphologically from Koch's vibrios from water supplies of places where cholera existed, or had recently occurred. Several tests were devised to differentiate the vibrio isolated from cholera patients and from the vibrios isolated from other sources. The cholera-red reaction, the character and rate of gelatin liquefaction, the hemolytic reaction, the pathogenicity for laboratory animals were each