SUMMARYPilobolus crystallinusutilized several carbon sources with sodium acetate giving the best growth. Maltose, palmitic acid, lactose and glucose supported moderate growth, whereas sucrose, starch and five other carbon sources supported relatively poor growth. Formic acid and oxalic acid were not utilized. The nitrogen sources glutamine and asparagine gave the highest mycelial yields. Glutamic acid and aspartic acid were better sources of nitrogen than potassium nitrate and urea. Ammonium sulphate at 1.6 g N/liter was inferior to glutamine and asparagine as a nitrogen source but it gave better mycelial yields at 0.14 g N/liter. Extracts made from cow dung of various ages did not stimulate growth.