Non-involvement of lysis during sporulation of Bacillus mycoides in distilled water.

Washed vegetative cells of Bacillus mycoides obtained and treated under specified conditions have been found to sporulate when shaken in distilled water under specified conditions. Within limitations of the methods, a heat-resistant cell (spore) is produced for each heat-sensitive vegetative cell present initially. Several different experiments designed to detect massive lysis and cell growth during sporulation in distilled water yielded uniformly negative results. Evidence is furnished for the conclusion that a freshly formed spore (heat-resistant cell) weighs considerably less than its progenitor vegetative cell. The observed results are most satisfactorily explained as a direct conversion of a vegetative cell to a spore.