In this paper, the developmental order of the vascular bundles was traced in the young shoot. In a transverse section through the stem, the leaf trace strands of the large type make their appearance first as the procambial strands in the fundamental meristem, and then follow the compound bundles. The leaf trace strands of the small type, the outermost peripheral bundles as well as the nodal plexus are the last to become differentiated. At the apical part of the growing stem, the lateral veins of the young leaves and the stem bundles are discontinuous in the early stage of their procambial differentiation, but become connected with each other. Such a feature is often observed in the case of the outermost peripheral bundles above and below a node. The discontinuity of the leaf veins and the stem bundles, however, does not take place at the basal part of the stem, where the intercalary elongation is depressed. This fact suggests to us that with reference to the continuity and discontinuity of the bundles in their early stages, there is no necessity of interpreting oppositely.<br>In general, the cells of the nodal region remain embryonic until the stage a little later than those of the internodal region, and the procambial differentiation seems to be delayed at the node, thus resulting in the discontinuous differentiation. However, in the part of the stem, where the internode is short, the time differences of the cell differentiation are not conspicuous between the nodal and internodal regions and the continuous type of differentiation is observed.<br>As already shown in the previous paper of the writer, two rings of vascular strands, irregularly arranged, are observed in the stem, one ring consisting of the outermost peripheral bundles, the other of the compound bundles which are situated less peripherally and scattered more irregularly rather than the outermost peripheral bundles. The leaf trace strands of the small type fuse with the bundles of the outer rung, and those of the large type, after descending within the pith through several internodes, fuse with the bundles of the inner ring. Two rings of the vascular strands resemble each other in respect of their behaviour at the node and in relationship to the leaf trace strands; and they seem to be homologous, in the fundamental plan of the vascular behaviour, to those found in the stem of the Commelinaceae and a few dicotyledonous plants.