“…The synthetic media used in investiga tions of aerobic spore formers are basically the same, varying principally in organic constitution (Roberts, 1934;Foster and Heiligman, 1949b;Grelet, 1946;Williams and Harper, 1951;Perry and Foster, 1955;Hanson et al, 1961). Table 1 shows the effect of several media, differing in organic composition only, on the sporulation of J3.…”