L. minor was grown in aseptic culture for 13, 14, or 27 days at 25[degree] C with continuous light (500 ft.-candles, fluorescent lamps) using fixed, limited quantities of nutrients. The effects of deficiencies in micro-nutrients are described. Efficiency in salt utilization was found to be dependent on the carbon nutrition level of the plant and reached a max. value of 16.3 (yield/salt) or the equivalent of 6.1% salts for each unit of yield. Quantity and quantity ratios of nutrient salts were important factors in growth.