Studies on the buffer action of roots of rice, wheat and barley : 〔II〕 The effect of the vital activity of the roots

1. In order to test the buffer action of roots, the adjacent segments of excised rice roots were separately submerged in acid wellwater. 2. The difference of buffer action between the roots which were cut in air and in wellwater was tested. The buffer action of the former was higher than the latter, due to the loss of cell sap from the cut surface of roots before submersion in the acid water. 3. The buffer action decreased after desiccation of roots before submersion in the acid water. 4. The buffer action was distinctly found in the roots which were treated with chloroform vapour for 10 minutes, but it was scarcely seen in the foots which were treated with 75% alcohol solution for 5 miniutes. 5. The buffer action of the apical zone was visible at 2°C, and 25°C., but the action was less at 2°C. 6. When CO2 gas was bubbled through the acid water used in these experiments for 1∼5 hours, the pH did not change. 7. It is presumed that the buffer action should have become functional by some substance which is formed in the process of metabolism of living cellls and penetrated througth the root tissue.