Abstract
Continuing studies on the causual nature of toxic action of copper-ions on the growth of rice plant, the following results are found. (1) The copper content of the root of plant cultured in the solution containing 100 ppm of copper with nutrients is estimated as follows : 1077 per 1 g. of fresh root in a part near the root-tip. 215 per 1 g. of fresh root in other part of the root. (2) The growth of the root is thereby inhibited. (3) the copper-ions thus absorbed are accumulated mostly in the cell of cortex, while they are difficultly reached to the cell of endodermic layers. (4) So, copper-ions are inhibited largely to move toward the stem and leaves. (5) The plant does not consequently suffer an injurious effect of the copper even in the ionic concentration of 100 ppm, if the half of the root is placed in the solution of the nutrients without copper.
