468 
Respiration, 291; gaseous inter- 
changes of, 291 ; masked by photo- 
synthesis, 292; loss of weight in- 
volved in, 295; intensity of, 297 ; 
nature of the process of, 299; 
relation of, to metabolism, 300; 
influence of external conditions 
on, 302; of seeds, 303; a source 
of energy, 304 ; intramolecular or 
anaerobic, 306 
Respiratory quotient, 297 
Rhamnase, 254, 259 
Rhamnus, 259 
Rhodophycee, 434 
Rhythm, of root-pressure, 88; 
nature of, 360; affected by stimu- 
lation, 403 ; induced, 404 
Ricinus, 182, 243 
Ripening, 457 
Robinia, 67 
Root-hairs, 73; action of, 74 
Root-parasites, 206, 350 
Root-pressure, 76, 86, 87; rhythm 
of, 88, 91; method of measuring, 
89, 91; amount of, 90; period- 
icity of, 92 
Rush, construction of stem of, 
116 
Saccharomyces, see Yeast 
Sacus, on theory of transport of 
water in wood, 84 
Salvinia, 113 ; germination of mega- 
spore of, 439 
Santalacec, 206, 350 
Saprolegnia, 402, 428, 459 
Saprophytes, 127, 191, 348 
Sarracenia, 194 
Saussure, Dn, on Opuntia, 302 
Saxifraga, 253, 344 
Saxifragacee, 298 
Scirpus, 32, 33 
Sclerenchyma, 25, 29, 30, 34 
Scrophularia, 452 
Scrophulariaceaw, 206, 350 
Scutellum, epithelium of, 
255 
Scyphanthus, 396 
Secretion, 267 
Seed, 440 ; formation of, 441 ; struc- 
ture of, 444; germination of, 
458 
Selaginella, prothallium of, 439 
Selective power, 181, 187 
Self-sterility, 453 
Sense organs, 411 
252, 
VEGETABLE PHYSIOLOGY 
Sensitiveness, 365; 
386; localisation of, 386, 392, 
411; delicacy of, 394, 418; 
maintenance of, 417 
Sex, differentiation of, 432 
Sexual cells, 430 
Sieve-tubes, 175, 224 
Silica, 56, 138, 279 
Silicates, 142, 186 
Silicic acid, 142 
Silicon, 135, 141, 180, 185 
Sinigrin, 245, 259 
Skeleton, of plastid, 2,42; of plant, 
34, 42 
Sleep movements, see Nyctitropic 
movements 
Slime fungi, see I yxomycetes 
Sodium, 135, 141, 180, 185 
Soil, composition of, 72 
Sorus, 451 
Spermatium, 445 
Spermatozoids, 432 
Sphagnum, 22 ' 
Spirogyra, 150, 157, 420, 426 
Splachnum, 191 
Sporangia, 428 
Spores, 428, 435 
Sporophyte, 435 
Stan on method of detecting escape 
of watery vapour, 95 
Starch, appearance of, during photo- 
synthesis, 158 ; probable cause of 
appearance of, in leaf, 160; forma- 
tion of, as evidence of activity of 
chlorophyll apparatus, 161; depo- 
sition of, in chloroplasts, 219, 234; 
removal of, from leaves, 230; 
storage of, 234; deposition of, by 
leucoplasts, 235; by protoplasm, 
237; digestion of, 254 ; secretion 
of, 270 
Statoliths, 392 
Stele of root, 75 
Stereome, 34 
Stimulation, 375; nature of, 377; 
purposeful nature of responses to, 
377, 415 ; localisation of, 387; 395 ; 
after-effects of, 407; perception 
of, 415 ; latent period of, 416 
Stimulus, nature of, 375 ; instances 
of rhythmic, 379, 381; of lateral 
light, 385 ; of gravitation, 388 ; of 
contact, 392; of moisture, 400; 
of oxygen, 401; chemical, 400 ; 
relationship of response to, 415 ; 
of fertilisation and_ pollination, 
456 
variations of, 
