522 



SUBJECT INDEX 



Steppe plants, assimilation of, 214 ; 

 osmotic pressure of, 52 ; 

 transpiration of, 214 



Stigma, 352 



of wind-pollinated plants, 377 

 sensitive, 389 



Stoma, closure of, 178 ; closure of, 

 in dark, 105 ; closure of, in 

 dry air, 105 ; closure of, at 

 mid-day, 172 ; closure of, 

 following shock, 105 ; closure 

 of, and leaf water content, 

 108 ; closure of, on wilting, 

 107 ; mechanism of, 103 ; 

 opening of, on wilting, 108 ; 

 protection of, in furrows, 

 180 ; protection of, in nycti- 

 nastic leaves, 206 ; protection 

 of, in pits, 17s sqq, ; structure 

 of, 84, 102 

 regulation of transpiration by, 



no, 160, 166 sqq. 

 diffusion of gases through, 84, 

 86, 88, 91, 96 sqq. 



Stomata, of marsh plants, 108, 171 ; 

 of nyctinastic leaves, 171 ; 

 of sun and shade leaves, 154 ; 

 of succulents, 108 

 dimensions of, 91 ; distribu- 

 tion of, 90 ; distribution 

 of, on nyctinastic leaves, 

 206 ; numbers of, 90, 185 



Stoma tal movement, 102 



and assimilation, no ; and dew 

 formation, 205 ; and external 

 conditions, 105 sqq., no, 

 167 sqq. ; periodic, 109 



Strand plants, dispersal of, 416 



Stratification of vegetation, 182 



Succulence, factors inducing, 197 



Succulents, of arid regions, 197 ; of 

 saline soils, 196 

 gas exchange of, 113 ; stomatal 

 movements of, 171 ; tran- 

 spiration of, 196 ; water 

 storage of, 161 

 stem, 196 



Suckers of parasites, 220, 222, 227, 

 23s, 236 



Suction force, 50 



ofepiderm, 163 ; of guard cells, 

 104 ; of leaves, 163 ; of 

 roots, S3 



Switch plants, 193 



Symbiosis, of ants and plants, 309 

 bacterial, 217, 258, 263, 264 ; 

 congenital, 248, 257, 265 ; 

 fungal, 240, 244 sqq. 



Tendrils, 226, 297 sqq. 



Therophytes, 451 



Time factor, 143, 158 



Toxic effects, of salts, 64 ; of organic 

 soil compounds, 65 



Toxins, of moorland soils, 191 



Transpiration, 81, 159 sqq. 



of compass plants, 125 ; of 

 moorland plants, 191 ; of 

 parasites, 228 ; of sclero- 

 phyllous trees, 212 ; of steppe 

 plants, 215 ; of submerged 

 plants, 201 ; of succulents, 

 162, 196, 212 ; of switch 

 plants, 193 ; of xerophytes, 

 260 

 in rain forest, 202 ; in wind and 



still air, 100 ; in winter, 186 

 extent of, 2, 159 ; limitation of, 

 by cuticle, 176 ; limitation 

 of, by ethereal oils, 185 ; 

 limitation of, by hairiness, 

 179 ; limitation of, by leaf- 

 fall, 186 ; limitation of, in 

 profile position, 187 ; limita- 

 tion of, by protected stomata, 

 17s ^QQ- ') limitation of, by 

 reduced leaf-surface, 185 ; 

 limitation of, by reduced 

 stomatal numbers, 185 ; pro- 

 motion of, 201 ; promotion 

 of, by drip-tips, 203 ; pro- 

 motion of, by excreted water, 

 202 ; promotion of, by nycti- 

 nastic movements, 204 ; pro- 

 motion of, in satin leaves, 

 204 ; regulation of, by cell 

 sap, 174, 175 ; regulation of, 

 by stoma, 167 sqq. ; regula- 

 tion of, by leaf water- content, 

 173 ; role of, 82, 203 sqq. 

 and assimilation, 273 sqq. ; and 

 external conditions, 164 ; and 

 wood conductivity, 188, 190 

 cuticular, 87, 88 ; relative, 165 ; 

 stomatal, 87 



Traumatotropism, of roots, 23 



Tropical plants, assimilation of, 158 



Tuber formation and fungus infec- 

 tion, 257 



Turgor, mechanical effects of, 284 

 pressure;, 50 



Twining plants, 226, 234, 296 



Vegetative multiplication, 314, 460 

 Velamen, 71 



of terrestrial roots, 72 



