Phyllopodium, 214 note. 

 Phyllosiphon Arisari, 28. 

 Physalis Alkekenghi, growth, 



451. 

 Physarum album, 14. (Fig. 



8.) _ 

 Physcia, 125; soredia, 124; 



zoospores, 124. 

 Physcia parietina, Figs. 83, 



84. 

 Physcomitrium, protonema, 



163. 



Physma, 125. 



Physma chalaganum, Fig. 84. 

 Physma compactum, apo- 



thecia, 122. 

 Phytelephas, endosperm, 395, 



429; seed, 430. 

 Phytolacca dioica, stem, 466, 



467. 

 Phytolaccaceae, 468. (Fig. 



400.) 



Phytocrene, stem, 466. 

 Phytophthora, 92, 96, 99. 

 Phytophthora infestans, 94. 



(Fig. 56.) 

 Phytophthora omnivora, 96 ; 



sexual process and germi- 

 nation, 99. 

 Picea, classification, 339 ; 



cone, 328. 

 Picea excelsa, archegonium, 



333- 



Picea vulgaris, embryo, 337. 

 (Fig. 260.) 



Pileus, 131, 132, 135. 



Pilobolus, 91. 



Pilularia, archegonium, 232; 

 leaves, 235, 236; macro- 

 spores, 232; microspores, 

 230 ; prothallium, 232 ; 

 sporocarps, 240 ; stem, 

 236. 



Pilularia americana, 240. 



Pilularia globulifera, 240,242, 

 243- (Figs. 191, 195, 197, 

 198, 199.) 



Pilularia minuta, 240. 



Pinus, 339; bilateral deve- 

 lopment, 321 note ; cone, 

 328, 339; female flowers, 

 326 ; floral axis, 323 ; leaf, 

 345; male flowers, 325; 

 phyllotaxis, 322 ; pollen- 

 sacs, 325; pollination, 325; 

 seed, 331. 



Pinus picea, Fig. 250. 



Pinus pinaster, archegonia, 

 333, 334- (Fig. 266.) 



Pinus pumilio, cone, 328. 

 (Fig. 260.) 



Pinus strobus, archegonia, 

 334; embryo, 337, note 2 ; 

 tertilisation, 335. 



Pinus sylvestris, branching, 

 320, 321 ; fertilisation, 

 325 ; flowers, 322. (Figs. 

 264, 265.) 



Piperaceae, cauline bundles, 

 308 ; floral diagram, 459 ; 

 floral envelope, 349; flower, 

 349; ovary, 376 ; ovule, 

 377, 382, 385; perisperm, 

 394; seed, 446; stem, 465, 

 466. 



Pipereae, 468. 



Piperineae, 468. 



Piptocephalideae, 91. 



Piptocephalis, 91 ; stilogoni- 

 dia, 10. (Figs, i, 55.) 



Pistia, endosperm, 441 ; sus- 

 pensor, 400. 



Pistilla, 145 note. 



Pisum, frujt, 428. 



Pitchers, 453. 



Pith, 462. 



Pittosporeae, 470. 



Placenta, 305, 370. 



Plagiochasma, branching, 

 162 ; sexual organs, 160. 



Planogametes, 5, 7. 



Plantagineae, 471. (Fig. 388.) 



Plantago, endosperm, 461; 

 fruit, 429; inflorescence, 

 411 ; protogyny, 405. 



Plantago arenaria, seeds, 4 30. 



Plantago Cynops, seeds, 430. 



Plantago Psyllium,seeds,43O. 



Plasmodia, 15. 



Plasmodiophora Brassicae, 

 14. 



Plasmodium, formation, 15, 

 16. 



Platanaceae, 468. 



Platanus, floral diagram, 459 ; 

 intrapetiolar buds, 451. 



Platycerium, branching of 

 leaves, 213. 



Platycerium alcicorne, apical 

 cell, 210; leaf-forms, 209. 



Pleospora, perithecia, 108. 



Pleospora herbarum, apo- 

 gamy, 102. 



Plerome, 302, 397. 



Pleurocarpous Mosses, 174. 



Pleurocladia, 65. 



Pleurococcus, 35, 41 ; in re- 

 lation to Lichens, 120, 125. 



Plocamium, 75. (Fig. 48.) 



Plumbagineae, 471 ; con- 

 ducting tissue, 390 ; fu- 

 nicle, 381 ; seed, 445. 



Podocarpeae, 339 ; leaves, 

 322; pollination, 325. 



Podocarpus, 339 ; aril, 330, 

 338; floral axis, 331 ; fruit, 

 339; ovule, 331; pollen- 

 grain, 325. 



Podocarpus chilina, 330. 



Podocarpus chinensis, 330. 



Podocarpus dacryoides, 330. 



Podocarpus macrophylla, 

 Fig. 256. 



Podophyllum, floral formula, 

 459 ; stem, 465. 



Podosphaera, 84, 101 ; fruc- 

 tification, 8, 100, 101, 104, 

 105. (Figs. 6, 63.) 



Podosphaera Castagnei, Fig. 



65- 



Podosphaera pinnosa, Fig. 

 65. 



Podostemaceae, 472 ; ab- 

 normal development, 461. 



Pogonatum, antheridia, 174. 



Polanisia graveolens, Fig. 

 346. 



Polar nucleus, 387. 



Polemoniaceae, 471. 



Pollen-grains, 300, 304, 363 ; 

 sculpturing, 365 note ; ho- 

 rn ologies, 365 note. 



Pollen-sacs, 301, 304. 



Pollinia, 369. 



Pollinodium (Ascomycetes), 

 101. 



Polybotria, 227. 



Polycarpellary, 372 note. 



Polycarpic perennial plants, 

 403. 



Polycarpicae, 468 ; floral 

 formula, 458. 



Polycarpous flower, 372. 



Polychidium, 124. 



Polygala grandiflora, flower, 



Fig. 353- 



Polygalaceae, 469. 

 Polygonaceae, 468; nucellus, 



305; ovule, 305, 377, 382; 



seed, 445 ; sporogenous 



tissue, 388; variation in 



synergidae, 389. 

 Polygonatum multiflorum, 



Fig. 357- 



Polygonum amphibium, 

 growth, 451. 



Polygonum divaricatum, nu- 

 cellus, 386. (Fig. 319.) 



Polygonum Fagopyrum, Figs. 



3i5, 3 2 5- 



Polygonum multiflorum, la- 

 teral shoots, 433. (Fig. 



357-) 

 Polyhedra in Hydrodictyon, 



40. 



Polyides rotundus, 80. 

 Polymerous (ovary), 372 and 



note, and 374. 

 Polypetalous, 352. 

 Polyphagus Euglenae, zygo- 



spore, 85. 

 Polypodiaceae, 194, 197, 198, 



