The Relation of the Growth of Certain Micro-organisms to the Composition of the Medium

DURING the growth of cultures of Streptothrix corallinus upon the basal medium [Reader, 1927] with addition of broth or antineuritic concentrates (torulin), it was noticed that the organisms were distributed sometimes at the surface and sometimes throughout the volume of the fluid. This rather haphazard phenomenon suggested the effect of a surface tension factor, and experiments were accordingly devised to determine whether surface tension had an effect upon (1) the amount of growth, and (2) distribution or type of growth.