The technique and methods of the in vitro culture of the embryos of cotton (Gossypium hirsutum) were studied. Embryos in different stages of development were excised from bolls of known ages, and placed on a sterile culture medium (White''s). Various supplements to the basal medium used were casein hydrolysate, malt extract, solns. of B vitamins, amino acids, coconut milk, tomato juice, and an extract of cotton ovules. Casein hydrolysate had the best growth-stimulating effects. Variations in the amt. of illumination, pH value of the media, and temp. of incubation failed to induce more rapid growth of the embryos. Embryos excised fr^m the plant and placed on the medium when 27 days of age grew rapidly and produced normal seedlings; those excised when 20 days old grew very slowly and frequently produced gnarled, twisted seedlings; embryos excised when 15 days old usually failed to grow, or produced small, spindly seedlings.