Abstract
A regular growth correlation was observed between the leaves and the roots in rice seedlings. Considering this phenomenon to be resulted from the translocation of substances from leaves to roots, the authors investigated into the changes in starch contents in the leaf-sheaths according to the position of them. 1. Morphologically intimate relationships were found between the vascular bundle system of the leaf at each node on the culm and that of the root. 2. As to the volumes and sizes of starch grains in successive leaf-sheaths, usually the third leaf from the top showed the highest values, and the other leaves either upper or lower showed gradual decreases in those values. This tendency was found the same not only in a main stem and in a tiller but throughout all the phases of growth. 3. It may be assumed that the translocation of substances from leaf-sheath to node begins at the third leaf from the top. 4. Judging from these results, the development of new roots begins at lower nodes in rice plants and proceed periodically to upper nodes.
