The Influence of Growth Hormone on Hypocotyls of Helianthus and the Structure of their Cell Walls

In the summer of 1935 we began experiments on the influence of indole-3-acetic acid (hetero-auxin), using this growth hormone dissolved in lanoline according to F. Laibach \ to learn above all something more on the Pisum-test of Went 2. We soon learned that the original explanation of Went regarding the inward curvatures of the slips of the longitudinal split internodes of Pisum, when they were put into a solution of hetero-auxin, could not be correct. Went attributed this curvature to the influence of the growth hormone on the cells of the cut surface. Although the application of lanolin with hetero-auxin on the intact outside of the slips caused beautiful curvatures, treatment on the cut inside of the slips with the same paste had no effect.