A study was made of the rates and paths of mineral-salt movement in Pinus faeda, using radioactive phosphorus P32 as a tracer. Rootlet tips were immersed in vials containing the phosphorus for periods up to 10 hr. The rootlet was then severed and the tree felled. Cross-sectional root and stem samples were taken and analysed. The results are tabulated. The highest translocation rate obtained for P32 in the lateral roots was 1.42 m. per hr.