Repression of the growth of the subsidiary buds at each eye of the potato by the dominant bud was prevented by soaking the potato in a solution of thiourea (NH2CSNH2). The sprouting of 2-8 buds from a single eye was forced by this treatment. Solutions of thiourea also prevented the apical buds of tubers from inhibiting the growth of basal buds. Certain cases were found in which the direction of dominance was reversed, apical buds being inhibited by the growth of basal buds. The relation of these facts to certain theories regarding the cause of bud inhibition is discussed.