SUBJECT INDEX 



521 



Root systems — cont. 



extensive, 27 ; generalised, 

 27, 33 ; intensive, 27 ; 

 specialised, 27, 35 



Salt, and transpiration, 196 



Salt marsh plants, osmotic pressure 



of, SI, S3 

 Salts, nutrient, 62 



absorption of, 66 ; absorption 

 of, by hairs, 75 ; absorption 

 of, by submerged plants, 69, 

 201 ; action of, on roots, 40 ; 

 balance of, 63 ; concentration 

 of, and plant growth, 63 ; 

 concentration of, in soil solu- 

 tion, 8 ; supply of, 2 ; 

 supply of, to insectivores, 

 281 ; supply of, and leaf pro- 

 duction, 455 ; supply of, and 

 flower production, 458 ; sup- 

 ply of, to mycorhiza, 246, 

 249 ; supply of, to parasites, 



221, 225, 236 ; supply of, to 

 subterranean fruits, 404 ; 

 supply of, and transpiration, 

 203 



Sandhill plants, root systems of, 32, 



46 

 Saprophytes, 217, 240 sqq. 

 Scent of flowers, 368 

 Scent, sense of insects, 368 sqq. 

 Sclerenchyma, 286 

 Scrub, thorn, 193, 448 

 Seed, dispersal of, 326, 407 sqq. ; 



by animals, 411 ; by birds, 



222, 227, 411 ; by ants, 412 ; 

 by explosive mechanisms, 

 227, 408 ; by hooks, 413 ; 

 by hygroscopic movements, 

 408 ; by mammals, 413 ; 

 by plant, 408 sqq. ; of para- 

 sites, 222, 227, 412 ; by 

 water, 415 ; by wind, 414 



dormancy of, 326, 421 sqq. ; 

 biological effects, 421 ; evo- 

 lution of, 326 ; food stores of, 

 325 ; germination of, 219, 

 222, 230, 231, 235, 247, 251, 

 432 sqq. ; maturation of, 339 ; 

 nature of, 325 ; resistance of, 

 324, 422 sqq. ; vitality of, 418 

 sqq. 

 viviparous, 431 



Seedling, emergence of, from soil, 

 436 



Self-pollination, 381, 382, 394, 398 



Self-sterility, 391 sqq. 



Senescence, 321, 459, 461 



Sex, determination of, 332 sqq. ; 

 distribution of, 329, 331, 338, 

 382 ; evolution of, 318 ; 

 inheritance of, 334 sqq. \ sig- 

 nificance of, 320 sqq., 339, 

 463 ; influence of external 

 factors on, 333 

 secondary characters, 339 



Shade plants, assimilation of, 151 ; 

 leaf structure of, 151 ; re- 

 spiration of, 151 



Sleep movements, of flowers, 349 ; 

 of leaves, 204 



Soil, colloidal properties of, 5, 6 sqq. ; 

 formation of, 3 sqq. ; nature 

 of, 2, 21 ; structure of, 3 ; 

 acidity of, 11 ; atmosphere 



as source of or game food, 241 ; 

 physically dry, 191 ; physio- 

 logically dry, 191 



bacteria, 17, 19 



colloids, 6, 9 



constitution and water supply, 



S6, IS 



fauna, 18 



flora, 19 



minerals, solution of, 68 



moisture, classification of, 13 

 sqq. ; relation of, to soil 

 constitution, 15 ; retention 

 of, in soil, 54 sqq. ; supply of, 

 to plant, 54 sqq. 



organisms, 17 sqq. 



reaction, 9, 11, 12, 42, 66 



solution, 6 sqq. ; composition 

 of, 8 sqq. ; concentration of, 

 8 sqq., 63 ; methods of 

 extraction of, 7 ; reaction 

 of, 9 



skeleton, 15 



temperature, 20 

 Span of life, 459, 460 

 Spines, 192 

 Spores, nature and characters of, 



320, 354 

 Sporophyte, 315 sqq. 

 Stamens, of angiosperms, 341 ; of 

 gymnosperms, 341 ; ofwdnd- 

 poUinated flowers, 377 



dehiscence of, 342, 354, 379 ; 

 structure of, 341 



sensitive, 390 

 Stem, mechanical features of, 288 

 sqq. 



as assimilating organ, 193, 194 



