The Guttation from Rice Seedling Leaves as influenced by Root Activity

1. In order to study the relationship between root activity and active absorption, the diameter of the drops of guttation water on the leaf tips of rice seedlings was mea- sured with a micrometer inserted into a low powered microscope. The roots of plants to be tested were submerged in the water adjusted to various temperatures with an electric water bath and the atmosphere for the tops was kept in high humidity. 2. The volume calculated from the diameter of each drop increased lineally with the time from the beginning of observation 3. The rate of guttation increased with temperature, but above a certain temperature this rate began to decrease. The temperature, at which the maximum rate of guttation was observed, differed with the growth stage of rice seedlings. The temperature rose with the increase of the growth stage