580 



INDEX 



Perennial stems, 171. 



Perfect flower, 13, 11*. 



Perianth, 11, 460, 11*, 460*. 



Pericarp, 61, 66*. 



Pericentral cell, 328. 



Pericycle, 147. 



Peridium, 390. 



Perigynous flower, 16, 15*. 



Perisperm, 46. 



Perisporiales, 364; described, 373- 



375. 



Peristome, 421. 

 Perithecium, 369, 370*. 

 Permanent root, 103. 

 Peronosporales, 353; described, 355- 



360. 



Petal, 12, 11*. 

 Petiole, 234. 

 Peziza, 366, 367*. 

 Pezizales, 364; described, 366-369. 

 Phaeophyceae, 318-324. 

 Phallus impudicus, 391, 392*. 

 Phellogen, 185*. 

 Phenotype, 554. 

 Phloem, 130, 146, 188. 

 Phosphorus, as a soil constituent, 157. 

 Photosynthesis, 169; described, 252- 



260; factors influencing, 257. 

 Phycocyanin, 297, 324. 

 Phycoerythrin, 324. 

 Phycomycetes, 352; described, 353- 



363. 



Phylogenetic divisions, 292. 

 Phylogeny, 291. 

 Phylloglossum, 438. 

 Physical basis of heredity, 535. 

 Phytophthora cactarum, 358, 361*. 

 Phytophthora infestans, 357, 358*, 



359*, 360*. 



Pigments, 281; described, 283. 

 Pileus, 386, 386*. 

 Pilobolus, 362. 



Pineapple type of fruit, 80, 80*. 

 Pine Blister-Rust, 402. 

 Pines (Pinaceae), 451-458; gameto- 



phytes, 455-457; life cycle, 457*; 



seed, 457; sporophyte, 452, 451*; 



strobili, 452-455. 



Pink, family, 480; flower, 481, 15*, 



481*. 



Pistil, 11, 11*; compound, 15; de- 

 scribed, 14, 462; simple, 15; 



structure, 33-37. 

 Pistillate flower, 14, 12*; of Corn, 18, 



19*. 



Pitcher Plant, 132, 272*. 

 Pith, 187, 187*. 

 Pitted vessels, 188, 190*. 

 Placenta, 77, 34*. 

 Plagiotropism, 173. 

 Plant Breeding, 557-565. 

 Plant Ecology, 2. 

 Plant food, nature, 120. 

 Plant Geography, 3. 

 Plant Pathology, 2. 

 Plant Physiology, 2. 

 Plant succession, 510-512. 

 Plasmopara Viticola, 355, 355*, 356*, 



357*. 



Plastids, 115, 251. 



Plectascales, 364; described, 375-377. 

 Pleurococcus vulgaris, 294, 307, 294*, 



307*. 



Plowrightia morbosa, 369, 370*. 

 Plum type of fruit, 78, 77*. 

 Plumule, 56, 466, 56*, 466*. 

 Podophyllum, 180, 180*. 

 Poisonous Toadstool, 384*. 

 Pollen, 41, 41*, 42*; function, 42; in 



relation to external factors, 49; 



structure, 41, 42*. 

 Pollen chamber, 448, 449*. 

 Pollination, 46; agents, 46; kinds, 47; 



kinds giving best results, 52; 



nature, 46; results, 50; self-, 



close-, and cross-, 48. 

 Polyadelphous flowers, 15. 

 Poly cotyledons, 67. 

 Polyembryony, 467. 

 Polygonaceae, 478-480. 

 Polygonum Muhlenbergii, 227, 479*. 

 Polypetalae, 481-489. 

 Polypetalous flowers, 13. 

 Polyporaceae, 387. 

 Polysiphoiria, 327, 328*. 

 Polysiphonia violacea, 328*. 



