INDEX 
Phycomycetes, 232. 
Physcia, 270-273. 
Physiology, vegetable, 1. 
Pigeon-wheat moss, study of, 281- 
285. 
Pileus, *264, 265. 
Pine, seedling, *33. 
Pine wood, *94. 
Pinne, leaflets of a pinnately com- 
pound leaf, 138. 
Pinnate, *133. 
Pinnules, *288. 
Pistil, *197, 201, 202, *203. 
Pistil, parts of, *203. 
Pitcher-plant, *540. 
Pith, *83, *87, *88, *89. 
Placenta, 203, *205. 
Plankton, 333. 
Plant colonies, 310. 
Plant formations, 310. 
Plant physiology, definition of, 1. 
Plant societies, 307-3823, *312, *322. 
Plants of uneatable texture, 348. 
Plants, classes of, in relation to 
economy of water, 311. 
Plants, destruction of, by animals, 
345. 
Plants, earliest appearance of, 298. 
Plants, mimicry by, 347, 348. 
Plasmolysis, 52, 53. 
Pleurococcus, study of, 244, 245. 
Plumule, 7. 
Pod, 219, 223. 
Poisonous plants, 352. 
Poisonous seeds, 24. 
Poisons, plants containing, 352. 
Pollarded trees, 128. 
Pollen, 201, 211, *212. 
Pollen-carrying apparatus, 
366. 
Pollen, discharge of, *211. 
355, 
407 
Pollen grains, *212. 
Pollen grains, number of, per 
ovule, 216. 
Pollen, protection of, from visitors, 
360-362. 
Pollen, protection of, from rain, 
*371, 372. 
Pollen tubes, 212, 213, *214. 
Pollination, 353-355. 
Polypetalous, 201. 
Polysepalous, 201. 
Polysiphonia, 255. 
Polytrichum, 281-285. 
Pome, 224. 
Pond-scum, study of, 241-244*. 
Potash in hay, 165. 
Potato tuber, 76, *78, 114-116. 
Prickle, *349. 
Prickly leaves, *349. 
Prickly pear, *315. 
Primary root, 36. 
Primrose, pollination in flowers of, 
*366, 367. 
Procambium, *96. 
Prosenchyma, 94, 95. 
Propagation, by root, 61. 
Propagation, means of, 
cryptogams, 373. 
Propagation of plants, 373-386*. 
Protection of plants from animals, 
345-352. 
Protection of pollen from rain, 
*371, 372. 
Proteids, 22, 23. 
Proteids, tests for, 23. 
Prothallium, 287, *289. 
Protococcus, *244. 
Protonema, 283. 
Protoplasm, 52, 178. 
Protoplasm, characteristics of, 181, 
182. 
among 
