Studies have been made on the translocation of C14-labeled solutes (2,4-D, 2,4,6-T and sugar(s)) and labeled solvent (THO or H2O18) in the red kidney bean. Transport of 2,4-D can be controlled by regulating the supply of carbohydrate in the leaves. For the first six hours following treatment of leaves with 2,4-D, the amount of 2,4-D transported to the epicotyl increases linearly with time. Over short time intervals the amount of 2,4-D transported is linearly related to the concentration applied. Over longer time intervals high concentrations of 2,4-D tend to depress transport somewhat. Transport of 2,4-D does not however saturate at concentrations which saturate the growth process of the plant.