When most of the grains were removed from wheat ears the remaining grains developed increased numbers of aleurone and endosperm cells, and the increased grain volume was accompanied by an enlarged endosperm cavity. The giant grains usually synthesized starch more rapidly than normal grains. Flag leaf photosynthesis was unaffected and additional sugar was retained in the culm and glumes. Total nitrogen and free amino acid content increased. Gibberellin and auxin concentrations were greater in the glumes of the partly degrained ears, and auxin in the grains was also greater than in equivalent grains from intact ears.