404 



INDEX 



Pagurus, reactions to shadows, 247; 

 249; modification in reactions of, 

 296. 



Palaemon, 264. 



Pandorina, orientation in light from 

 two sources, 87, 147; function of 

 eye-spot, 109, 147; 136; structure 

 of, 146; locomotion of, 147; orien- 

 tation and change in sense of, 

 147, 231; 171; aggregation of, 242. 



Papaver, 288; 313. 



Paramecium, 17; 45; 82; reactions 

 to light, 134, 135, 361; 142; 324; 

 344; 350; 366. 



Paramecium bursaria, method of 

 aggregation (Engelmann), 16; 45; 

 aggregation of, 240; effect of oxy- 

 gen on reactions of, 279; reactions 

 in spectrum, 323, 324; 374. 



Parker, definition of tropism, 56; 

 orientation in earthworms, 198; 

 201; 202; 214; on circus move- 

 ments, 216; 221; 223; effect of 

 size of illuminated area on reac- 

 tions, 227; 244; 250; 265; 274; 

 effect of contact on reactions, 

 284. 



Patten, 247. 



Payer, reactions of seedlings in spec- 

 trum, 314, 317, 319. 



Pearse, orientation in holothurians, 

 211; 221; 247; decoration in crabs, 



357. 



Peckham, 354. 



Pecten, 247. 



Pelomyxa palustris, 74. 



Perichaeta bermudensis, 199. 



Pfeffer, 12; 17; 21; 59; 60; 94; 100; 

 warming-stage, 274; sleep move- 

 ments in plants, 286; effect of dif- 



« 



ferent rays on reactions, 303; 317. 

 Phacus, aggregation of, 241; 274. 

 Phagocata gracihs, 207. 

 Phalaris, 19. 



Photokinesis, defined, 35. See TJnter- 



schiedsempfindlichkeit. 

 Photopathy, defined by Davenport, 



40, 41; 55; 56; 241; defined, 253- 



256; compared with phototaxis, 



254; 302. 

 Photosynthesis, 311, 312, 361. 

 Phototaxis, defined by Davenport, 



40; 55; defined by Hadley, 56; 



217; defined, 253-256; compared 



with photopathy, 254; 302. See 



Heliotropism. 

 Phototropism. See Heliotropism. 

 Phycomyces, 265; 318. 

 Physiological states, dependence of 



reactions upon, 49; effect of, on 



reversal in reactions, 284-287; 



Jennings on, 372-375- 

 Pilobolus, 318. 

 Pinnularia, 323. 



Pisa, 355- 



Planaria, accuracy of orientation, 

 206; locomotion and rate of loco- 

 motion, 207-210; method of aggre- 

 gation, 210; 254; 257; 261; 270; 

 346; 366; maculata, 207; gono- 

 cephala, 207; torva, 255. 



Plants, theory of orientation in: 

 (Darwin), 18-21, (Loeb), 30; re- 

 actions of, in light, 59-73; sensi- 

 tiveness of, 288, 313, 319; effect 

 of different wave-lengths on re- 

 actions of, 310, 313-320, 361; 

 effect of mixed rays on reactions 

 of, 362. See Table of Contents. 



Planulae of Eudendrium, 87. See 

 Eudendrium. 



Plateau, 354. 



Plumules, orientation of, 63-69. 



Poggioli, effect of different rays on 

 reactions of plants, 314, 321. 



Pollock, transmission of stimuU in 

 roots, 31, 59; theory of root curva- 

 ture, 71. 



