Abstract
The writer has studied on the life history of rice plant from the view point of nutrio-physiology. In these studies, the rice plants were treated as a whole plant. But this whole plant is constructed from many tillers and these tillers are constructed from many leaves. So, the macroscopic studies in which plants are treated as a whole, have only quantitative meaning. If it is desired to know the physiological condition of the rice plant at any stage of growth qualitatively, analytical studies must be made in which the many parts that make up the whole plant are dealt with. So, the writer of this paper studied morphological characteritics of development of leaves on mainstem a definite positions. The following results were obtained. (1) Leaf-length reflects the environmental condition under which the leaf developed. (2) Ratio of leaf-blade-length to leaf-sheath-length of upper leaves is larger than that of lower, except the boot leaf. (3) Lower leaves grow first and then the upper ones grow successively. The longevity of upper leaves is greater than that of lower. (4) Proportion of materials which can translocate from leaf to another part in relation to total leaf weight is larger in upper leaves than in lower. These facts suggest that each definite leaf has its characteristics of the physiological function corresponding to its position on stem.
