抄録
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.
