INDEX 



563 



Rigor, 526. 



Ringing, 48, 171. 



Root, conditions of origin of, 338 ; functions 

 of, 26 ; size of, 28 ; periodicity of growth 

 in, 346 ; branching of, 26, 97, 283 ; ab- 

 sorption of water by, 28 ; growth of, 289 ; 

 corrosion figures of, on limestone, 94 ; 

 pressure, see Bleeding ; hairs, 28 ; func- 

 tions of, 93, cap, 283 ; tendrils, 495. 



Rotation, 536. 



Rubidium, 83. 



Saccharomyces, as causing alcoholic fer- 

 mentation, 208. 



Saprophytes, 178. 



Scale and foliage-leaves, 349. 



Scion, 334. 



Secondary growth, 294; eccentric, 314; 

 contraction during, 295. 



Secretion of peptic enzymes, 184 ; of acids, 

 184; of water, 50, 57. 



Seeds, see Germination. 



Segment cells, 280. 



Segregation in hybrids, 375 ; in Cytisus 

 adami, 381. 



Selection, 384-6; of nutrients, 180. 



Self-regulation, phenomena of, 184, 255, 525. 



Semipermeability, 12, 13. 



Sexual-cells, injurious influence of, 376. 



Shock-stimuli, 516; in Cynareae, 519; in 

 Mimosa, 511 ; in styles, 520; in other 

 structures, 517, 520. 



Shoots, sprouting of, 290, 344, 345 ; elonga- 

 tion of, 290; development of, 345, 346. 



Shrivelling, movements due to, 409. 



Sieve-tubes, 172. 



Silica, 87. 



Siliciferous plants, 99. 



Silicon. 87. 



Size, specific, 340. 



Soap films, 270. 



Sodium, 83, 86. 



Soil, absorption by, 92 ; employment of, by 

 the root, 26, 96 ; occupation of, by plants, 

 97 : origin of, 90 ; nutrients in the, 91 ; 

 oxygen in the, 25 ; primitive, 90 ; alluvial, 

 90 ; water contents of, 25 ; and agricul- 

 ture, 101 ; and plant distribution, 97 ; 

 plants local and indifferent to, 97. 



Solution, theory of, 16 ; colloidal, 153. 



Soma, somatic, 273. 



Somatic cells, initials of, 380. 



Specialists, 180, 182. 



Species, definition of, 384 ; primary or sub-, 

 385 ; origin of, by mutation, 393 ; origin 

 of, according to Darwin, 384 ; characters 

 of, 385. 



Spermatozoa, 359, 543. 



Spindle threads, 268. 



Spiral arrangement of members, 275. 



Spiral, fundamental, 275. 



Spontaneous movements, 521. 



Sporangium, dehiscence of, 415. 



Spores, ejection of, 422. 



Spring plants, periodicity in, 351; shoots 

 of, 346- 



Stamens, movements of, 425, 520. 



Starch, as a product of assimilation, no; 

 translocation of, 147 ; formation of, from 

 sugar, &c., 112; transitory, 171; disso- 

 lution of, 149. 



Statocysts, statoliths, 442. 



Stem climbers, 495. 



Stigma, stimulation of, by shock, 520. 



Stimuli, 255, 298, 496; in general, 427, 

 522; chemical, &c., see the individual 

 stimuli ; special, 427 ; specific, 522 ; ap- 

 plication of, 524 ; movements in response 

 to, general characters of, 521 ; chain of, 

 525 ; intensity of, in relation to reactions, 

 526; transmission of, in Drosera, 498; 

 in heliotropism, 468, 469, 470, 475 ; in 

 Mimosa, 518; in tendrils, 493 ; media of, 

 428, 524 ; materials acting as, 88 ; re- 

 action to, 428. 



Stock, 334. 



Stomata, 37 ; absorption of carbon-dioxide 

 by, 1 20 ; structure of, 38 ; mechanics of, 

 39 ; opening of, effect of external factors 

 on, 40-42. 



Stretching of the cell-wall, due to osmotic 

 pressure, 419. 



Strontium, 85. 



Structure, specific, 339. 



Style, sensitive, 520. 



Stylidium, autonomous movements in, 529. 



Suberin, 4. 



Substance, embryonic, 273. 



Substratum, orientation in reference to, 

 486. 



Succinic acid, in fermentation, 210. 



Sugar, formation of, from fat, 199 ; pro- 

 moted by low temperatures, 175. 



Sulphur, 83, 145 ; in Beggialoa, 220; Bac- 

 teria, colourless, 223 ; new group of, 229; 

 red, 223. 



Sulphuretted hydrogen, 221. 



Sulphuric acid, assimilation of, 145 ; for- 

 mation of, by Beggiatoa, 221. 



Superelongation in darkness, 305 ; in ab- 

 sence of nitrogen, 315. 



Surface tension, 537. 



Surfaces of minimum area, 270. 



Swarmspores, 354. 



Swelling, 406. 



Symbiosis, 237, 325. 



Symmetry, 274. 



Taxis, 541. 



Temperature, influence of, on growth, 299 ; 

 as a formal condition, 252, 526, 540; 

 formative effect of, 301 ; cardinal points 

 of, 300, 526 ; of the plant, 399; alteration 

 in, effects of, on growth, 342 ; as a sti- 

 mulus to movement, 500, 505 ; reduction 



