Many different strains of Bacillus cereus and members of other species of the genus Bacillus were induced to lyse by exposure to the proper concentration of mitomycin-C, a radiomimetic drug. For some bacilli, induction of lysis occurred only in Casamino acids containing medium but not in nutrient broth + yeast extract medium, whereas other bacilli showed the opposite behavior. The efficiency of induction was a function of the growth phase of the culture and of the concentration of mitomycin-C. Induction of lysis in B. thuringiensis resulted in the release of edema factor and phospholipase into the medium. Mitomycin-C-induced lysis of B. cereus was prevented by adding chloramphenicol, actinomycin-D, or 5-fluorouracil deoxyriboside up to 40 min. later. There appeared to be no sequential loss of susceptibility to inhibition by these compounds as expected.