INDEX 



461 



pileus, 380 



Pinacea, 343 



pine, 24s, 252, ,308, 309, 333, 338, 343, 



3S4, 431 et seq. 

 pineapple, 333 

 pinnate leaves, 206 

 pioneer plants, 394, 404 

 pistil, 60, 272, 290 

 pistillate cones, 432, 434 

 pistillate flowers, 264, 281 

 pitcher plant, 253 

 pith, 77, 81, 82, 145, 146. 166, 419 

 pith-rays, 167, 168 

 pitted vessels, 174 

 placenta, 291 

 plantain, 212, 299 



plant breeding, 15, i5, 220, 446 el seq. 

 planting of trees, 196 

 Pleurococcus, 363 

 plowing, 104, 226 

 plumule, 342, 353 

 pod, 330, 331 

 poison ivy, 128, 152 

 pollen, 60, 27s, 308, 433, 437 

 pollination, 261 et seq., 301 el seq. 



of pine, 432 

 pollen basket, 311 

 pollen sacs, 272, 432, 433 

 pollen tube, 268, 269, 275, 435, 436 

 Poly gala polygama, 321 

 polygamous flowers, 284 

 polypetalous, 286 

 Polylrichum, 406 

 pome, 331, 332 

 poplar, 49, 53, 284 

 poppy, 331 



Populus tremuloides, 285 

 porcupine grass, 334, 335 

 potassium, 103, 349, 362 

 potato, 48, 158, 159, 346 

 primary growth, 129 

 primary roots, 123 

 primrose, 319, 320 

 proboscis, 311 

 Pronuba, 315, 316 

 prop roots, 48 

 prostrate stems, 149 et seq. 

 protection, 45 

 protection of leaves, 241 

 protection of seeds, 338 

 proteins, 229, 341, 344, 346 

 prothallium, 419, 420, 421 



protonema, 406, 407 



protoplasm, 72 e< seq., 110 et seq., 118 



protoplast, 73 



Prunus arbutifolia, 262 



pteridophytes, 361, 398, 414 et seq., 440 



pubescent, 213 



Puccima, 387 et seq. 



puiiballs, 383, 384 



pulvinus, 208, 247 



quack grass, 157 



quartz, 100 



queen's lace, 29s, 300 



R 



raceme, 298, 299 



radial arrangement, 139 



radial symmetry, 286 



radicle, 341, 342 



radish, 125 



Ranunculacea, 290 



raspberry, 126, 332 



rate of growth, 86, 166, 348 



receptacle, 276 



red algiE, 372, 373 



region of elongation, 130 



regular corolla, 286 



reforestation, 196 



reproduction, 28, 40, 363, 397, 405, 417, 



423 

 reserve cellulose, 347 

 respiration, 225 et seq. 

 response, 45, 133, 157 

 retention of megaspore, 431, 435 

 rhizoids, 405, 407, 421 

 rhizome, 155 et seq., 415, 418 

 Rhodophycea, 372 

 rhubarb, 137 

 Riccia, 396 

 rice, 341, 345 

 Rivularia, 364 

 rock phosphate, 103 

 rockweed, 372 

 root branches, 1 28 

 root-cap, 130, 134 

 root contraction, 140 

 root excretions, 79, in, 137 

 root-hair, 46, 47, 78, 135 et seq., 218 

 roots, 4S et seq., 123 ct seq. 



