The growth of the mold Stachybotrys atra on a modified Waksman-Carey medium has been studied. Iron, zinc, copper, and manganese have been shown to be inorganic micronutrients for the mold but their essential nature has not been conclusively demonstrated. Certain other supplements appear to stimulate growth. When ammonia is the nitrogen source, the mold makes good growth only with sugars and related compounds as carbon sources; the only other carbon source readily utilized is acetate. High activity for the hydrolysis of salicin and sodium carboxymethyl cellulose appears in the medium at and just after the germination of the mold. In unbuffered media a second maximum is associated with the attainment of maximum mycelial weight. Enzymic activity against pi-nitrophenyl-beta-glucoside does not appear to be closely correlated with the other two activities. The meaning of these results is discussed in terms of the hypothesis of multiple beta- glucosidase activities and the non-existence of a specific Cx enzyme.