456 



INDEX 



Nodes, 1 86 



Nuclei, 31, 33, 34, 40, 55, 62, 66 



Nutation, 187. 



Oak, swamp white, 192 



Oat, rusts, 69 ; smut, 386, 387 



Odors of flowers, 361 



Oils, essential, 324; fatty, 320-322; 



volatile, 324 

 Opuntia, 204 

 Orange, 285 

 Orchid family, 300 

 Orchids, epiphytic, 183 

 Ovary, 8, 9, 137, 144, 159, 160 

 Ovules, 8, 123, 124, 126, 128, 144, 



145, 160 



Palisade layer, 139 

 Palm family, 297 

 Pandanus, 175 

 Panicle, 266 

 Parasitic bacteria, 12 

 Parasitic fungi, 60, 80, 85 

 Parasitic seed plants, 179-181 

 Parsley family, 307 

 Pasteurization of milk, 20 

 Peach scab, 388 

 Pear blight, 374 

 Pear rust, 73 

 Peas, 27, 153 

 Peat mosses, 94 

 Pedicels, 141, 264 

 Peduncles, 141, 264 

 Pepper, 323 



Perennial plants, 177, 221, 331 

 Perfumes, 323 

 Petals, 8, 9, 142, 148, 260 

 Phaseolus acutifolius, 155 

 Phaseolus lunatus, 154, 155 

 Phaseolus multijlorus, 154, 155 

 Phaseolus radiatus, 155 

 Phaseolus vulgaris, 154, 155 

 Phycomyces, 59 

 Pigeon grass, 329 

 Pilobolus, 59 



Pine, blister rust, 72; comparison 

 with bean, 153; long-leaved yel- 

 low, 352; red (Norway), 352, 

 356; white, 348, 349, 352 



Pineapple, 284 



Pines, 113-136 



Pink family, 303 



Pinus Lambertiana, 133 



Pinus palustris, 352 



Pinus resinosa, 133 



Pinus strobus, 132 



Pistils, 8, 141, 144, 159, 160, 263; 

 rudimentary, 9, 160, 161 



Pitcher plants, 236, 237 



Pith, 115, 116, 138, 196, 211 



Plankton, 51 



Plant breeding, 358-372. 



Plant diseases, 373-389 



Plant products, 313-327 



Plum black knot, 383 



Pod of bean, 144, 151, 152 



Poison hemlock, 337 



Poison ivy, 340 



Poison oak, 340 



Poisonous plants, 80, 81, 337-341 



Pollen, 9, 268; as food for insects, 

 272; of bean, 143, 144, 148; of 

 cucumber, 9; of Indian corn, 161 ; 

 of lily, germination, 143 ; of pine, 

 122, 123; of pine, germination, 

 125; sacs, 122, 123, 161; tube, 

 9, 126, 129, 143, 147, 148, 149 



Pollination, 266-280; of bean, 146- 

 148; of Indian corn, 162 ; of pine, 

 125, 126, 129 



Polygonatum, 199 



Pond scums, 39 



Potato, 314, 358; early blight, 388, 

 389; late blight, 380; rot, 380; 

 scab, 387; tubers, 202 



Powdery mildews, 382 



Pressure, influence on growth, 185 



Prickles, 220 



Prickly lettuce, 240 



Primrose, flowers, 278, 279; leaf 

 mosaic, 239 



