1. The criticisms by Grollman (7) of the cryoscopic method for the determination of bound water as proposed by Newton and Gortner (1) have been considered, and it is pointed out that even admitting the correctness of his contentions does not negative the conclusion that bound water values as determined by the cryoscopic method parallel in a remarkable manner the physiological responses of plants to environmental conditions. 2. A new method of calculating the true freezing point of a solution is proposed. 3. Gum acacia in aqueous sucrose solutions shows positive amounts of bound water to the extent of 0.6 to 0.7 gm. of bound water per gram of gum. 4. Gum acacia in aqueous solutions of KCl and KBr shows slightly negative amounts of bound water, indicating a preferential adsorption of the solute rather than the solvent.