抄録
The volumes of plant organs and their intercellular spaces can be simply measured by means of measuring both gravity and buoyancy methods. The latter method surpasses the former one in accuracy of measurement. The buoyancy method is achieved by the following way: materials are first weighed in air (G1), secondary weighed in the submerged condition in water (G2), and once again weighed in water after having been infiltrated with water using an electric vacuum pump (G3); in the case of gravity method materials are once more weighed in air (G4), in addition to the weighing procedure of three times mentioned above. Then, the volume of the material is computed in mm3 from G1-G2 in the c se of buoyancy method and from G4-G3 in the case of gravity method. The volume of the intercellular spaces is computed in mm3 from G3-G2 in the buoyancy method and G4-G1 in the gravity method, respectively. At the measurement of leaf volume, it was confirmed that the measuring errror was less than 1%. By these methods, it is possible to measure not only in the case of turgescent organ but also wilted one. Using vacuum pump, precaution should be taken lest air should be remained in the organ. However, it was also confirmed that the measuring error owing to the above cause did not exceed 2% at 20°C. In addition, some conceivable theoretical errors caused by shrinking, deformation, infiltration of the leaf, etc. were discussed. But it was certified that they were quite negligible in this experiment.
