Cell cultures ofNicotiana tabacum were grown on M & S medium containing 0-2.0 ppm of two auxins. Cellular nicotine was estimated for given auxin concentrations and highest levels determined. Feeding suspensions with amino acids either alone, or in combination with nicotinic acid and nicotinamide produced decresed nicotine levels. The presence of anatabine, anabasine, myosmine, anatalline and nicotelline in the cultures was established and it was noted that precursor feeding which decreased nicotine concentration caused elevated levels of the other alkaloids, notably anatabine.