1. The toxicity of killed dysentery bacilli can be ascribed to the somatic antigen. Antibodies to intact dysentery bacilli apparently contain no toxin-neutralizing antibodies other than those which precipitate the purified somatic antigen.
2. The serological properties of dysentery bacilli are determined by the specific somatic antigen. The specificity and cross-reactivity of the somatic antigen are dependent upon the carbohydrate moiety of the molecular complex.