362 



INDEX 



Peronospora, 142. 



Petal, 221, 222. 



Petiole, 6. 



Phseophyceae, 116. 



Phloem, 52; root, 74. 



Photosynthesis, 18, 87. 



Phototropism, 92. 



Phycomycetes, 144. 



Pileus, 155. 



Pine, timber, 218. 



Pineapple, 281. 



Pirus, 289. 



Pistil, 228. 



Pitcher-plant, 35. 



Pith, 50; ray, 51. 



Plains, 341. 



Plant associations, 324; cactus 

 desert, 341; deciduous forest, 

 350; mangrove swamp, 336; 

 meadow, 345; mesophytic thick- 

 et, 348; peat-bog, 336; plain, 

 341; pond weed, 328; reed- 

 swamp, 331; rock, 338; salt and 

 alkaline desert, 344; salt marsh 

 and meadow, 336; salt steppe, 

 344; sand, 338; subtropical 

 desert, 341; swamp, 331; swamp 

 forest, 336; swamp thicket, 332; 

 tropical forest, 355; xerophytic 

 forest, 344; xerophytic thicket, 

 344. 



Plant-breeding, 316. 



Plasmolysis, 115. 



Plastid, 104. 



Pleurococcus, 102. 



Plum, 289. 



Plumule, 86; escape of, 91. 



Pod, 238. 



Pollarding, 70. 



Pollen, 242; Angiosperm, 224; 

 conifer, 212. 



Pollen-sac, 226; conifer, 212. 



Pollen-tube, Angiosperm, 236; 



conifer, 217. 

 Pollination, Angiosperm, 242; 



conifer, 217. 

 Pollinium, 248. 

 Pome, 289. 

 Pomelo, 299. 

 Pomology, 289. 

 Pond-scum, 113. 

 Pondweed association, 328. 

 Pore Fungi, 156. 

 Potato, 305. 

 Prairie, 345. 

 Profile leaves, 29. 

 Pronuba and Yucca, 244. 

 Prop-root, 80. 

 Protection, leaves, 24. 

 Proteid, 88. 

 Prothallium, 193. 

 Prothallus, 193. 

 Protoplasm, 87, 103. 

 Prune, 289. 

 Prunus, 288. 



Pteridophytes, 183, 207, 208 

 PurTball, 158. 

 Pumpkin, 315. 

 Pyrenoid, 114. 



Quince, 291. 

 Quinine, 309. 



Raceme, 232. 

 Rain, leaves, 32. 

 Ranunculacese, 284. 

 Raspberry, 287 . 

 Ray, 310. 

 Reaction, 93. 

 Receptacle, 240. 

 Red Alga3, 124. 

 Redwood, 219. 

 Reed swamp, 331. 

 Reforestation, 323. 



