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In the previous paper Tanaka, one of the writers, reported the developing process of the lateral roots growing from the main root in the leguminous crop plants, which according to its developing condition could be classified into three types, namely alfalfa, vetch and intermediate types. In this report the main roots of crops belonging to those three types were anatomically observed and compared with each other. 1. In alfalfa type, initials of lateral roots are formed adjoining each other, and also appear at varying times (Fig. 1, B-I∼VI, C). Consequently, the formation of meristems for rooting was recognized on the main root (Fig. 2, D-I, II). 2. The development of the medullary ray of the root differ with the crop and type (Fig. 3, E-I∼V), and is considered to have a close relation with the development of lateral roots. 3. It was also recognized that the secondary thickening growth of the root also differs with the crop and type (Fig. 4). Generally, the alfalfa type showed a tendency to grow more in thickness than the vetch type.

1. This experiment was attempted to make clear the growth of the adventitious roots that developted from the hypocotyls, by using nine species of summer legumes as samples. 2. It was observed that the number of the developed adventitious roots (hypocotyl roots) was the same with the number of vascular bundles because of the fact that their primordia were formed by the division of interfacicular parenchyma. 3. The growth of hypocotyl roots of the soybeans for which earthing up was practised on the 25th and the 30th days after sowing was greater than that in those plots for which earthing up was practised on any other dates. 4. The two types were recognized in the secondary growth in thickness of the hypocotyls, and a close relationship was found between the two types of the secondary growth in thickness of the hypocotyls and the development of the hypocotyl roots.

The present study was undertaken to investigate, according to the previous paper, how to change the development of branching, curvatures and the shooting angles of roots in successive nodes when wheat and corn were planted under the different kinds of soil and manure. The following results were obtained: 1. The height and number of tillers were greater in compost plot and heavy fertilized plot and were inferior in clay plot. 2. The curvature and branching of rots were more developed in compost plot and sand plot but were meagerest in clay plot (Fig. 1, 2). Therefore number and length of secondary and tertiary roots were superior in compost plot and sand plot than in clay plot. 3. In compost plot the rot angles were large and elongated horizontally, but in sand plot the angles were smaller (Fig. 3, 4). From these results, it can be said that the root angle is influenced by soil conditions and there is a tendency that the root angle is larger when the plant is more grown.

In the previous paper, the author reported some results concerning the correlation between growth of the primary roots and development of the leaves at the successive nodes of the main stem. In this expeliment, the author observed that correlation exists between development of the branch roots and the leaves. 1. The secondary roots began to branch regularly, with the elongation of the primary roots, from the base of the primary roots to the tip. 2. Development of the primary roots, secondary, tertiary and the fourth roots etc. proceeded at the same pace as the emergence period of the leaves. 3. When the growth of the above-ground parts was restrained and also when the growth of the roots was promoted by cutting, the development of the branch roots and emergence of the leaves showed the regularity which was recognized above. Judging from these results, we are assured that the close relationship exists in these matters. 4. We also can use the degree of development of the branch roots as a standard to distinguish old and the new roots.

As the development of roots begins at lower nodes and proceeds periodically to upper nodes, the roots from the upper nodes are younger than those from the lower nodes. In this experiment the author investigated physiological and morphological differences of foots elongating from the successive nodes of the main stem. 1. Coloring of the roots : In both rice and wheat, it was observed that the young fresh white color diminished and the yellowish brown color deepened successively from the upper nodes toward the lower ones. 2. Size of the roots : As these roots do not have secondary thickening growth, in principle, the size of a root base is constant throughout all the phases of growth. Diameters of root bases in upper nodes were larger than those of lower nodes. The root of the largest diameter was observed in the 10 th node in rice plant and in the 6 th node in wheat-it was 1.36 cm in rice and 1.26 cm in wheat. And conversely diameters of those root bases upper than the largest successively decreased. 3. Number of the roots : In a rice plant the number of roots increased successively from the lower node towards the upper node-the largest unmber was observed in the 10 th node-it was 23.3. A wheat plant has commonly 3 in every node. 4. Amount of the oxygen absorption in water : As the upper the roots were the younger, they absorbed larger amount than those of the lower nodes. The difference of the amount in the successive node of a rice plant was larger than that of a wheat plant. 5. Angle of the roots emergence : The angle of the roots emergence to the main stem became larger successively from the lower nodes toward the upper nodes-the roots of the 11th node presented 92.1 on the average.

In the previous papers, the authors have reported some interesting results concerning the correlation between growth of the leaves and development of the roots at the successive nodes in the rice plants and in the wheats. In this experiment with Zea mays L., the authors studied again on the correlation described in the previous papers. 1. Period of the leaf elongation in the Zea mays L. was shorter than that in the rice plants. This might possibly be due mainly to the numerous leaves of the main stem and short vegetation period. Five to six leaves were elongating together at the same time in a given period of the growth. 2. The nodal roots of a certain node shooted during the two leaves of the main stem emerged from under-nodes to upper ones in the Zea mays L.. 3. Therefore the upper the nodes and the roots were located, the more fresh, numerous and the bigger they were. 4. The authors considered that such correlation (mentioned above) between leaves and roots in the cereals may be ascribed to the development of the node

As previously mentioned (1959), branching of root, ie, formation of primary, secondary, tertiary rootlets and so on, proceedes at the same pace as the leaf emergence at a successive node in rice, wheat and corn plant. In this experiment, the auther has planned to observe morphologically the mechanism of root branching and to make clear the growth of roots in paddy rice. The results obtained were: 1. In a transverse section of the roots in rice, wheat and corn it was observed that, the branch-roots originate from the cell of the pericycle opposite the phloem of the vascular bundle of its root, but not from the points opposite the xylem. Conseguently, the formation of the branch-roots is correlated with the number of the phloem. Therefore, with late maturing varieties the number of the branch-roots, is greater than with earlier maturing varieties because the late maturing varieties have many phloems than those of the earlier ones. 2. Observing morphologically the root branching, it was found that branching has a close relationship with the curvature of the root. The branch-roots are produced usually at the convex portion of the curvature, but not at the concave portion. Moreover the greater is the curvature the greater and bigger the branch-roots. And also when the roots were curved artificially, the same tendency was recognized as in the natural condition. 3. When we compare the curvatures of the roots growing in paddy field condition with these in up-land condition, the former was more gentle than the latter and big branch-roots were few in paddy field condition than in up-land.

We are investigating the differences in physiological properties of seedlings of rice varieties differing in their time of maturation. In our previous studies on the respiration of root of rice seedlings, the superiority of root activity of late maturing varieties over that of early maturing varieties was recognized. In this experiment the difference in the guttation and bleeding of seedlings of various varieties were examined. 1. The guttation increased in parallel with the lateness of varieties, i. e. late maturihg varieties showed always greater amount than earlier ones. The rate of guttation was as follows: in early maturing varieties, 100; in the medium, 121.1 and in the late, 159.8. 2. When rice seedlings were cultured in different concentrations of distilled water solution of sucrose, we confirmed that the guttation of early maturing varieties was always inferior to that of the late ones. Therefore the osmotic pressure of the roots of earlier maturing varieties seemed to be lower than that of late ones. 3. In bleeding also we could perceive the same tendency as in guttation.

The experiments were undertaken with water-cultured rice seedlings of 14 varieties as materials, the absoption of oxygen being measured by the method of WINKLER, and the results obtained were as follows: 1. The absorption of oxygen in late maturing varieties was found faster than that in early ones. 2. The transference of oxygen from above-ground parts to roots in late maturing varieties was found faster than in the early ones. 3. From the results it was considered that late maturing varieties are more tolerable than early ones against oxygen deficiency.

Experiments were conducted to investigate the correlation between growth of roots and growth of above-ground parts of the wheat plant on the basis of KATAYAMA's studies on tillering. The results obtained were as follows: (1) About the time when the third leaf of the main stem emerged, its first crown roots appeared at the coleoptile node. The same phenomenon was observed in the tillering system. (2) The tillers and the roots emerged and elongated almost simultaneously at the same node of the main stem, and the same was true of the tillerstems. (3) Roots and tillers emerged in regular directions, as shown in Fig. 1.