562 



INDEX 



Periodic movements, 508 ; origin of, 509 ; 

 mechanics of, 510. 



Periodicity, 340 ; in leaf- formation, 343, 

 348 ; in secondary growth, 350 ; in 

 development, as a whole, 351; in longi- 

 tudinal growth, 344 ; yearly, 343-8 ; 

 daily, 342 ; in tropical plants, 347. 



Performance of work, 247, 397 ; in geotropic 

 curvature, 437 ; in imbibition, 408 ; in 

 turgor and growth, 422. 



Permanent tissue, 296. 



Petiole, 292. 



Phosphorus, 83, 145. 



Photonastic, 500, 502, 531. 



Phototaxis, 549, 552. 



Phototropism, 460. 



Physiology, problems of, i. 



Pilobolits, ejaculatory movements of, 423. 



Pith, geotropic behaviour of, 435. 



Pits, 46, 170. 



Plagiotropic, 445. 



Plant materials, 4. 



Plasmatic layer, osmotic characters, 22. 



Plasmodia, movements of, 534 ; chemical 

 composition of, 8. 



Plasmolysis, 14. 



Plastic stretching, 265. 



Pneumathodes, 38. 



Poisons, effect of, on growth, 316; as 

 stimuli, 87. 



Polarity, 330, 333, 336. 



Poles, 273. 



Pollen-tube, conditions of germination of, 

 317 ; directive movements in, 483. 



Polygonum aniphibitim, adaptation in, 253. 



Posterior side, 276. 



Potassium, 83. 



Potometer, 30. 



Precipitation membranes, 13. 



Predominant characters, 373. 



Pressure, influence of, on organogenesis, 

 338; on lateral roots, 315; on division 

 planes in the cell, 314; on growth and 

 formation, 314; negative, of the air in 

 vessels, 70 ; osmotic, in external medium, 

 179, 418 ; variations in, 318 ; significance 

 of, 20, 419; determination of, 18, 420; 

 amount of, 18, 419; regulation of, 419; 

 theory of, 17 ; effect of, 420 ; as a stimulus, 

 314, see Contact ; exerted by the growing 

 plant, 422. 



Primitive organisms, 258. 



Production of energy in the plant, 397-404. 



Progressive development, 274. 



Prophase, in nuclear division, 268. 



Protease, 152, 160. 



Proteids, 4, 140; formation of, 115, 138; 

 from amido-compounds, 173; chemistry 

 of, 139; subdivision of, 140; as reserves, 

 159, 163, 165 ; decomposition of, 139, 161; 

 respiration of, 200; fermentation of, 219; 

 organisms, 182. 



Protein, see Proteid. 



Protoplasm, 6 ; amoeboid movements of, 

 534 ; explanation of, 537 ; formal condi- 

 tions of, 539; rotation of, 536; circula- 

 tion of, 536; permeability of, 19, 20; 

 causes of, 21 ; structure of, 9, 10 ; growth 

 of, 259 ; composition of, 7. 



Putrefaction, 219. 



Qualitative division, 380. 



Qualities, mechanical explanation of, 254. 



Racemic acid, 181. 



Races, 384, 388. 



Radial growing point, 276. 



Ranunculus aquatilis, adaptation in, 253. 



Reaction, see Perception ; purposeful, 254 ; 



forms of, 428. 

 Recessive characters, 373. 

 Reduction division, 367, 378. 

 Reflex actions, 525. 

 Regeneration, 328-9 ; from the single cell, 



380 ; from somatic cells, 380 ; causes 



of, 336. 



Rejuvenescence, 366, 37 1. 



Releasing agents, 255, 339, 428, 522, 527. 



Reproduction, 353 ; in Algae, 353 ; in 

 Basidiobolus, 249; digenous, 371; in 

 ferns, 358; sexual, 249, 355 ; by embryos 

 and buds, 355; monogenous, 371; in 

 Phanerogams, 360 ; asexual, 249, 355 ; 

 causes of, 355 ; relationship of, to growth, 

 357 ; organs of, 353 ; accessory, 359, 362. 



Reproductive-leaves, 349. 



Reserve organs, 329. 



Reserves, 147, 148, 161, 162. 



Resins, 4. 



Resistance to flexion in articulations, 506, 

 514. 



Respiration, 190; dependence of, on de- 

 velopmental condition, 194 ; on light, 201; 

 on oxygen, 202 ; on material influences, 

 201 ; on temperature, 201 ; on water, 341 ; 

 significance of, 205 ; history of our know- 

 ledge of, 205 ; amount of, 1 93 ; intra- 

 molecular, 203, 316; coefficient of, 197, 

 199; dependent on materials, 199; and 

 production of light, 401 ; materials used 

 in, 196, 208; demonstration of, 192; in 

 the green cell, 194; primary decomposi- 

 tion in, 204; products of: alcohol, 204; 

 carbon-dioxide, 192 ; organic acids, 197 ; 

 water, 196 ; causes of, 203, 204 ; occur- 

 rence of, 191 ; production of heat in, 201, 

 400, 



Rest period, 345. 



Retting, 218. 



Reversible enzyme actions, 154. 



Rheotaxis, 548. 



Rheotropism, 486. 



Rhinanthaceae, parasitism in, 188. 



Rhizomes, geotropism in, 446, 448. 



Rigidity, of the stem, 251 ; of the cell, 251, 

 419. 



