INDEX 



294 ; localization of, 286, 287 ; physics 

 of, 288 ; rate of, 284 ; theories of, 289, 

 290, 291 ; types of, 284. 



Protosiphon botryoides, 305. 



Prowazek, 176. 



Prunus, epinasty of, 254. 



Pseudopodia, forms of, 275, 281. 



Pterostylis, movements of labellum of, 22. 



Pulsating vacuoles, 290, 293 ; action of, 296, 

 297 ; character of, 294 ; frequency of, 

 295 ; function of, 299 ; influence of 

 external agencies on, 298 ; of tem- 

 perature, 317. 



Pulvini, changes of turgor in, 139 ; ex- 

 pansive energy of, 32, 136; influence 

 of absence of oxygen on, 143 ; of 

 chloroform and ether on, 144 ; of in- 

 duction-shocks on, 145 ; - - of light 

 on, 141, 142 ; of operations on, 76, 

 77, 136, 137, 138; of shaking on, 

 140 ; of temperature on, 141 ; growth 

 of, when inverted, 245 ; localization of 

 irritability in, 196 ; mechanism of, 13, 

 3i> 75> 76, 134; rigidityof, 18, 77, 135 ; 

 twisting of, 104. 



Purple bacteria, 306. 



Putter, 266, 358 ; on galvanotaxis,36i, 362, 



363, 364- 



Pyrenomycetes, dispersal mechanism of, 

 192. 



Querton, 394, 396. 



Quincke, 277, 281, 292, 299, 304. 



Quinic acid, chemotropic action of, 181. 



Raciborski, 36. 



Radius of cell, influence of, on resistance to 



streaming, 288. 



Radius of curvature, influence of, on surface- 

 tension pressure, 277. 

 Radium rays, influence of, on germination,' 



415 ; non- tropic action of, 176. 

 Radziszewski, 387. 

 Rameaux, 379, 381. 

 Ranke, 390, 394, 398. 

 Ranunculus aquatilis, heliotropism of roots 



of, 232: R. Ficaria, thermonastic 



flower of, 113. 

 Raphanus, 182. 

 Ratschinsky, 242. 

 Ray, 79, 113. 

 Reaction periods, 211. 

 Rectipetality, 190. 

 Reinke, 291, 327, 382. 

 Resistance, influence of, on curvature, 234, 



236, 237 ; path of least, in streaming 



cells, 292, 293. 

 Respiration, influence of curvature on, 208 ; 



relation of, to heat-production, 369,370; 



to streaming, 286; intramolecular, 



production of heat by, 374, 378. 

 Keticuloplasm, 303. 

 Revolutive nutation, 21. 



Rhabdoid, 89. 



Rheotaxis, 356. 



Rheotropism, 184, 185. 



Rhipidophora, 327. 



Rhizomes, geotropism of, 164, 219; position 

 of, in soil, 248, 249. 



Rhizomorpha, luminosity of, 383, 384, 385, 

 386. 



Rhizopus nigricans, streaming in, 284. 



Rhodomela, fragmentation of, 148. 



Rhumbler, 305, 307, 312, 357, 365 ; on pro- 

 toplasmic movement, 276, 277, 279-82, 

 286, 288 ; physics of, 292, 294, 296- 

 9, 302, 304. 



Richards, on production of heat, 371, 375. 



Richter, 20, 165, 169, 174, 204, 419 ; on irri- 

 tability of root-apex, 197. 



Ricinus, 330. 



Ricome, 218. 



Rigidity of pulvini, 31, 32. 



Rimbach, 164 ; on depth of rhizomes, 249. 



Rischawi, 188. 



Ritter, 306; on influence of oxygen on 

 streaming, 338, 340, 341, 342. 



Robinia, 13 ; latent period and movement 

 of, 68, 69; orienting torsion of, 233, 

 photonasty of, 98 ; sleep-movements 

 of, 102 ; /?. hispida, 80 ; R. pseud- 

 acacia, geotropism of hypocotyl of, 165 ; 

 reaction of operated pulvinus of, 138 ; 

 seismonic irritability of, 80, and of R. 

 viscosa, 80. 



Rodewald, 403, 404, 407 ; on production of 

 heat, 369, 371. 



Rodier, 19. 



Rodrigue, 13. 



Roesele, 360, 363. 



Romer, 372. 



Rontgen rays, influence of, on germination, 

 415 ; tropic action of, 176. 



Root, aerotropism of, 180, 182 ; curvature 

 of, 232, 237, 248 ; measurement of 

 growth during, 239, 240 ; resistance 

 overcome by, 238 ; galvanotropism of, 

 1 88 ; geotropism of, 163, 164 ; helio- 

 tropism of, 173 ; rheotropism of, 184 ; 

 thermotropism of, 177 ; traumatropism 

 of, 185, 1 86. 



Root-apex, localization of irritability in, 196, 

 197, 198, 418, 419. 



Root-hairs, response of, to contact, 83. 



Root-tendrils, 32. 



Rosanoff, 337. 



Rosenberg, 83, 90 ; on cellular changes in 

 Drosera, 89. 



Ross, 165. 



Rostafinski, 153. 



Rotation, 283 ; during free-swimming, 265, 

 266, 267. 



Roth, 84, 356. 



Rothert, 6, 18, 27, 150, 153, 155, 182, 187, 

 189, 232, 233, 234, 269, 293, 307, 309, 

 310, 311, 313, 355, 416, 419, 42i; on 



