Abstract
1. The O2 consumption so each day due to the respiration of the rice roots, grown is. 2. The O2 sonsumption was increased rapidly since the beginning of panicle differentiation or culm elongation, attaining its maximum at the beginning of heading, and decreased gradually thereafter. 3. The rate of respiration of rice roots varied parallel with the temperatures of the solution; even at the booting or heading stage it dropped suddenly at lower temperaures. 4. As almost all the oxygen in the cultural solution was exhausted during a daytime or a day, the theory that the oxygen transports from the aerial parts of the plant to the roots might be supported.
