Grafts et al. 



240 



Water in Plants 



coordination of, 13, 16, 29 



diffusion pressure of {see Diffusion pressure) 



dipole character of, 13 



dipole moment of, 23 



equilibrium in cell, 71-72 



free energy of, 76-77 



inexpressible, 121 



intracellular distribution, 59-72 



intercellular movement of, 108-109 



loss and retention, 179-208 



movement in xylem, 154-177 



non-solvent, 25 



of cell walls, 62-65 



orientation in xylem elements, 155 



packing of and tension, 155 



partition, methods for determining, 70-71 



passive absorption of, 151 



physical properties of, 3-6 



plant organs as reservoirs of, 172 



protoplasmic, 65-69 



quasi-lattice structure, 29 



redistribution, 172-174, 203 



self ionization of, 10, 11 



structure of, 2-6, 3-17 

 early theories, 4-7 

 modern studies, 9-15 

 current research, 15-17 



thermal properties of, 3, 4, 29 



valence forces in, 9 



viscosity of, 16 



X-ray analysis of, 11-14, 15 

 Water absorption, active {see also Active water 

 relations), 149-151 



active mechanism of, 104-105, 149-150 



by roots, 148-154 



DPD influence on, 153 



passive, 149 



root structure and, 148-149 



salt absorption, relation to, 174 



solute accumulation influence on, 149 

 Water-absorptive power, 50 

 Water balance, 172-174, 193, 200 

 Water conduction {see Water movement) 

 Water content of plants, 61-62 

 Water continuity, direct observation of, 160-162 



dye penetration and, 156-159 



freezing stems and, 159-160 



in xylem, 155-162 



methods of study of, 156 



transpiration and, 160 

 Water deficit, physiological effects, 200-203 



plant response to, 152-154 

 Water drops, contact angle of, 188 

 Water equilibrium, 52 

 Water in vacuoles, 69-70 



Water loss {see Transpiration, and Guttation) 

 Water movement, adhesion and, 154-155 



conducting tissue, 154 



diffusion pressure and, 154 



effect on transpiration, 193-194 



physical theories of, 154 



quantity of material moved, 168 



rate, 167-172 



resistance to, 162 



surface tension and, 155 



vitalistic theories of, 154 

 Water of constitution, 64 

 Water of crystallization, 29 

 Water relations, thermodynamic treatment of, 



76-77 

 Water requirement, 187, 198, 199 

 Water saturation, 98, 102 



Water secretion, 111-113, 116, 117, 118, 126, 

 143 



active water absorption compared with, 149 

 Water storage cells, 59 

 Water vapor, coordination of, 22 

 Watermelon, water content, 62 

 Wax treatment effect on transpiration, 198-200 

 Weight method of DPD detn., 104 

 Wilting, effect on stomata, 160 



sequence of, in plants, 152, 173 



soil moisture and, 152-153 

 Wind velocity and transpiration, 183 

 Wood rays, OP of, 100 



Xanthium pennsylvanicum, flower stimulation in, 

 176 



strumariutn, OP of xylem exudate, 100 

 Xeromorphic condition, 200 

 Xeromorphic leaves, 195 

 Xerophyte, 135 

 Xylem, as a conductor, 154 



as a reservoir, 161 



contraction in, 157 



exudate, 100 



food transport in, 157 



liquid continuity in, 155-156 



parenchyma, OP of, 99 



plugging of, 185 



resistance in, 162 



tension values in the, 104, 162-167 

 Xylol, in infiltration method, 197 



Yield, DPD and, 153 



Yucca, use as hygrometer, 186 



Zea, water deficit and photosynthesis, 201 



water requirement of, 198 

 Zea Mays, OP of xylem exudate, 100 

 Zostera marina, stimulative plasmolysis, 124 



