Water in Plants 



239 



Subject Index 



translocation of, 175, 177 



as plasmolyzing subst., 82 

 Suction force (see also DPD), 50 

 Suction pressure (see also DPD), SO 

 Suction tension (see also DPD), 50 



internal water movement and, 172 

 Sulfur, thermal properties of, 4 

 Sulfur dioxide, thermal properties of, 4 

 Sunflower, wilting of, 173 

 Surface tension, 4 



and injection of xylem, 157 



role in water movement, 155 

 Sweet pea, 4-chlorophenoxyacetic acid effect on, 



177 

 Swelling pressure (see also Imbibition pressure), 



28, 29 

 Symphytum officinale, vacuolar sap of, 69 

 Symplast, 61, 174 



role in water absorption, 149 

 Syneresis, 69 



Syringa oblata, DPD in, 106 

 Syringa vulgaris, internal leaf surface, 195 



subaqueous transpiration in, 205 



Tactoids, 67 

 Tannins, 69 



Taxus baccata, expressed sap of, 119, 120 

 Tensile strength (see Cohesion) 

 Tension, direct measurement of, 162 

 effect on tracheae, 157 

 fluctuations in, 148 

 gas formation and, 156 

 injection method of determining, 166-167 

 in xylem, 162-167 

 manometric measurement of, 162 

 newer methods of estimating, 165-167 

 potometric measurement, 162-163 

 "suction tension" measurements, 164-165 

 water absorption and, 151 

 xylem shrinkage and, 172 

 Tetrahydrone, 5 



Thermal properties of substances, 3-5 

 Thermoelectric detns., of OP, 91, 97 



of rate of sap movement, 170 

 Thiamin, translocation of, 176-177 

 Thorium B, use in sap movement expts., 169 

 Tissue tension method of DPD detn., 105 

 Tissue, volume changes of, 112, 126, 131 

 Tobacco, phloem parenchyma cell of, 60 



rate of sap flow in, 169 

 Tolypellopsis stelligera, water permeability of, 



80 

 Tomato, translocation in, 177 



water content of fruit of, 62 

 Tonoplast, 78, 87, 125, 143 

 TP (see Turgor pressure) 



TP„ (see Turgor pressure at normal cell vol- 

 ume), 131 

 TP, (see Turgor pressure at water saturation), 



131 

 Tradescantia, hair cells of, 60, 85 



xylem contents of, 161 

 Translocation, of herbicides, 157 



of solutes, 174-177 

 Transpiration, 183-200 

 cuticular, 184, 187-189 

 effect of disease on, 198-200 

 effect of dusts, sprays, waxes on, 198-200 

 effect of osmotic pressure on, 104 

 expression of results, 186-187 

 fluctuations in rate, 165, 189-192 

 genetic factors and, 197 

 indicators for study of, 175-176 

 internal factors affecting, 192-198 

 internal surface effect on, 194-195 

 lenticular, 184, 187 

 methods of measuring, 184-186 

 mineral nutrient effect on, 198 

 rate of, 179, 187, 188 

 resistance to water movement and, 193-194, 



198 

 stomatal, 184, 199 



stomatal regulation of, 197-198 



subaqueous, 203-205 



wall structure affecting, 192-193 



water absorption and, 151 



water continuity and, 160 



wilting effects on, 160 

 Trentepohlia aurea, OP of, 101 

 Triacontane, 187 

 Tridymite, 12 

 Trihydrone, 5 

 Trihydrol, 4, 5, 13 

 Triticum vulgare, leaf cuticle of, 187 

 Turgor, deficit, 50 



defined, 44-45 



of plant cells, 107 



measurement of, 107-108 



role of, 107, 140 

 Turgor pressure, and the mechanics of osmosis, 

 48 



at different cellular states, 73-75, 98, 131 



defined, 45 



relationship to OP and DPD, 50-82, 73-75, 98, 

 102, 107, 131 

 Turpentine, 197 

 Tyloses, 154, 156, 157 

 2,4-D (see Phenoxyacetic acid), 117 



Ultimate wilting, 154 

 Umbilicaria, water content of, 61 

 Uronide chains, in cell wall, 192 

 Ursolic acid, in cutin, 187 

 Urtica dioica, OP of, 99 



V (see Tissue, volume changes of), 98 

 Vacuolar, contraction, 71, 88, 125, 145 



"envelopes," 78 



sap, 69-71, 117-119 ^ 



Vacuoles, solutes in, 69 



water in, 69-71 

 Vacuolization, 68 

 Valence, bonds, 22 

 Vallisneria, permeability of, 80 

 Valonia, sap of, 70, 138 



macrophysa, 127 



urticularis, 127 

 van der Waals', equation, 19, 40 



surface tension and, 155 



forces, 14, 21, 23, 67 

 Van't Hoff's law, 18, 32, 34 

 Vaporization, calc. of surface tension by, 155 

 Vapor pressure, 41, 54 



deficit, 182 



equation, 28, 33 



gradient, 181 



liquids, 181, 182 



methods for detg. DPD, lOS 



methods for detg. OP, 95-97 



solvent, 38 

 Vicia faba, guard cells of, 87 



rate of sap flow in, 169 

 Vinca minor, sap of, 120 

 Vinca rosea, internal leaf surface of, 195 

 Virus, movement of, 175 

 Viscous flow, activation energy of, 15, 16 

 "Vitaids", 68 



Vitis vinifera, sap of, 120 

 Vitis vulpina, int. leaf surface of, 195 

 Volume measurement, immersion method, 104 



Wall (see Cell wall) 



Water I, II, III, 12, 13, 27 



Water, absorption of (see Water absorption) 



active absorption of, 104-105, 149-150 



active relations, of cells, 111-147 



anomalous properties of, 9 



as a plant component, 59-72 



association of, 5, 6, 8, 36 



availability, methods of estimating, 151-154 



binding forces, 24, 25, 26, 61-62, 63, 64 



capillary condensed, 64 



cavities in, 17 



cohesion of, 154-155 



continuity and movement of, 154-162 



