1. Germination and growth data indicate that tomato-juice-agar solutions are more effective than the synthetic culture media containing only sugar and salts used generally for the asymbiotic germination of orchid seeds. These tomatojuice solutions are more strongly buffered in the pH range, 4.5-5.5, for good growth, even when the concentration of KH2PO4 in the synthetic solutions is increased from 0.025% to 0.6%; likewise the pH values in the good growth range are not altered by autoclaving. Apparently the availability of the iron compounds in the tomato-juice solutions is not affected by either autoclaving or continued growth. 2. Ashing of the tomato-juice solutions definitely indicates that organic rather than inorganic compounds are responsible for the enhanced growth. A protein hydrolysate, rich in amino acids and vitamins, added to the inorganic solutions, allowed more rapid growth than even the tomato-juice media. Concentrations of protein hydrolysate greater than 1%, however, are toxic to Cymbidium...