Carbohydrate utilization and nitrogen requirement of Trichophyton gypseum were studied and differences in the nutritional physiology between the normal and pleomorphic forms of this fungus were demonstrated. The pleomorphic form showed better growth and more efficient assimilation on monosaccharides than the normal form. Dior polysaccharides generally failed to support appreciable growth of either form. The pleomorphic form grew far more readily on single amino acid than the normal form, and reproduced even on ammonium nitrogen to some extent which the normal form could not utilize at all.