Plant parts with a plasticity of nm.orphogenetic responise have provided useful experimental material for study of the hormiional control of organ formation. Of particular value are cases in which alternate organ-forminig potentials can be attributed to the same cell or group of cells. In the formation of endogenous buds anid lateral roots from Convolvulus arvensis roots, both types of organs originate from a small number of pericycle cells at sites opposite the protoxylem poles. Several years ago, Torrey (14) reported that a clone of roots of this species had been established from the radicle of a seedling germinated in 1952, making possible controlled investigations of the physiology of organ formation in continuous root cultures. The majority of physiological studies of bud and root formation in roots deals with thickened root cuttings. Organ formation in these cases is generally observed either in regions surrounding old lateral root traces or from callus tissue developing at cut surfaces. In either situation organ formation from root cuttings was found to be polar, with bud formation at the proximal4 end and root formation or callus growth at the distal end. Plant (9). workinig with root cuttings of Crambe, Warmke and Warmke (17), with Taraxacumn and Cichoriumn cuttings, Emery (4), with Chamacnelion cuttings, and Lindner (7), with Cochlearia cuttings, found that auxin application to the proximal end of the root cuttings resulted in inhibition of bud formation, promotion of root formation, and suppression of the polarity of organ formation. It was suggested that the polarity of organ formation in untreated cuttings resulted from differences in auxin concentration at the ends of the cuttings. Lower auxin concentrations at the proximal end promoted bud formation and higher concentrations at the distal end promoted root formation. Lowering the auxin level at the distal end should then result in bud formation at both ends. Stoughton and Plant (11) repeatedly excised 1-mm slices at 5-day intervals from both ends of Crambe cuttings to remove auxin accumuilating at the distal end and to prevent new synthesis of auxin by buds which would otherwise form at the proximal end. After 8 weeks of this treatment, cuttings regenierated buds at both ends. Warmke and Warmke (17) attempted to confirm the theory of auxin control over bud and root formation in Cichorium cuttings by extraction and bioassay of the endogenous auxin. Forty-eight hours after excision of the cuttings, they found that there was a somewhat greater amount of auxin activity in the neutral fraction extracted from the distalend than from the proximal end. By 96 hours there was more auxin activity in the free auxin fraction extracted from the distal end than from the proximal end. An investigation of the chemical control of polar organ formation in Convolvulus root segments was undertaken to determine whether the same control mechanisms described for thickened root cuttings are operative in endogenous bud and root formation from the pericycle of culttured roots comprised of only primary tissues.