792 



BOTANY 



Perichaetium, 492 



Periclinal cell walls, 307 



Pericycle, 95, 136 



Periderm *160, 162 



Peridineae, 386 



Peridiniaceae, 386 



Peridinium, *386, 387 



Perigone, 546 



Perigynous flower, *549, 550 



Periodicity, 304 



Periplasm, 500 ' 



Perisperm, 581 



Peristome, 495 



Perithecium, 439 



Periwinkle, Vinca minor 



Peronospora, *77, *433 



Peronosporeae, 431 



Persea, 639, *640 



Personatae, 696 



Petals, 197 



Petasites, 718 



Petiole, 108 



Petroselinum, 682 



Petunia, *697 



Peziza, *445 



Phaeocystis, 380 



Phaeophyceae, 409 



Pliaeosporeae, 412 



Phaeothamnion, 380 



Phalloideae, 468 



Phallus, 468 



Phascum, 496 



Phaseolus, 673 ; pulvinus of, *337 



Phelloderm, 162 



Phellogen, 162 



Phelloid tissue, 59 



Philadelphia, 659 



Phleum, 734 



Phloem, 68 



Phobophoto taxis, 330 



PJwenix, 740 



Phormium, *112 



Phosphorescence, 277 



Phosphoric acid, assimilation of, 262 



Photonasty, 357 



Photosynthesis, 254 



Phototaxis, 330 



Phototropic perception, localisation of, 

 351 



Phototropism, 348, *349, 351 ; a pheno- 

 menon of irritability, 351 ; transverse. 

 350 



Phmgmidium, 455, 456, 457, *458, *459, 

 460 



Phycocyan, 19, 423 



Phycoerythriu, 19, 423 



Phycomyces, 435 



Phycomycetes, 428 



Phycoxanthin, 411 



Phyllactinia, 440, 441 



Phyllocactus, 629 



Phylloclades, 171 



Pliylogeny, 2 



Physalis, fruit of, *584 



Physarum, *384 



Physiology, 215 ; object of, 215 



Physostigma, 673 



Phytelephas, 740 



Phyteuma, 70? 



Phytolacca, 95 



Phytopathology, 303 



Phytophthora, 431, *432 



Picea, *599, 600 ; embryo, *568 ; ovule 



of, *567i 

 Picorhiza, 704 

 Picrasma, 654 



Pilobolus, 434 ; phototropism, 349, *350 

 Pilocarpus, 654 

 Pilostyles, *189 

 Pilularia, *512, 516, 517 

 Pimenta, 676 



Pimpinella, *678, 681, 683 

 Pinaceae, 593, 596 

 Pine, radial section, *152 ; tangential 



section, *153 ; transverse section, *151 

 Pinguicula, 186, 704 

 Pinnularia, *74 

 Pinus, 600, *601, 602, 606 ; archegonium 



of, *567 ; embryo, *568 ; germination, 



*587 ; male flower, *544 ; pollen- 

 tube, *566 

 Piper, 95, *622, 623 

 Piperaceae, 621 , 

 Piperinae, 621 

 Pistacia, 655 

 Pisum, 672 

 Pith, 95 



Pithecoctenium, winged seed of, *585 

 Pits, *35, *42, *43 ; bordered, 65 ; tactile, 



353 



Pitting, 43 

 Placenta, 539, 547 

 Placentation, axile, 548 ; free central, 548 ; 



parietal, 548 



Plagiochila, 80, *81, *488, 489 

 Plagiogeotropism, 342 

 Plagiotropous, 72, 123 

 Plankton, 74 

 Planktoniella, *388 

 Plant geography, 244 

 Plantaginaceae, 704 

 Plantago, 704 ; inflorescence of, *559 

 Plantain, Plantago 

 Plants, chemical composition of, 220 ; 



organs of, 71 ; perception in, 338 ; 



sensation in, 338 ; size of, 281 ; 



stability of, 60 

 Plasmodesms, *44 

 Plasmodiophora, 385 

 Plasmodiophoraceae, 385 

 Plasmodium, 13, 382 

 Plasmolysis, *226 



