826 



INDEX. 



Pith, elongation of, 572, 573. 

 Pit-canals, 92. 

 Pitted- vessels, 136. 

 Pits, 92, 423. 



— bordered, 137, 160, 237, 

 424. 



Plagiotropic organs, 698, 

 703-705, 711. 



— organs, rolled up, 706, 

 707, 709. 



— and orthotropic organs 

 contrasted, 705. 



Plagiotropism, 489, 492, 494, 



709, 710, 712, 713, 714. 

 Planarise, 298. 

 Plant ago lanceolata, 129. 



— major, 220, 



— media, 792. 



— psyllium, 90, 

 Plant-life, external condi- 

 tions of, 189. 



Plants in the tropics, 197. 

 Plasmodia, 82, 429, 604, 

 615. 



— irritability to light, &c., 

 615. 



— movements of, 614. 

 Plasmolysis, 213, 567, 568, 



617, 653. 



Plastic substances, 326, 329, 

 413, 767. 



active and passive con- 

 ditions of, 341. 



translocation of, 329, 



353, 357, 361. 



Platanus, 166, 279. 



Platycerium IVilUngkii, 32. 



Plectranthus friiticosus, 121. 



Plerome, 143, 420. 



Plum, 90, 147. 



Plumule, 3, 41, 332, 344, 414, 

 492, 505, 680, 694, 702, 

 712, 717, 753, 764. 



Pogostemon patschouli, 185. 



Polarity, 481, 484, 485. 



Polemoniacea:, 780, 



Pollen, 761, 789. 



— nuclei of, 761, 771. 

 ■ — protection of, 797. 



— grain, 76, 92, 98, 99, 739, 

 751, 754, 756, 757, 758, 

 760-762, 769, 778. 



762. 



development of, i o i . 



mother-cells of, 433. 



sterile cells of, 756. 



sacs, 757, 760. 



— -tube, 751, 754, 755, 756, 

 758, 760, 762, 768, 771- 

 773,778. 



Pollination, 329, 535, 538, 

 754, 757, 760, 781, 790, 

 792. 



— oi Aristolochia, 792-794. 



Pollination of Orchids, 796, 

 797- 



— of Salvia, 794. 



— oiFiola tricolor, 794, 795. 

 Pollinia, 796. 

 Pollinodium, 726, 727. 

 Polygonacea:, 55, 186, 419, 



465, 470. 

 Polygonattim, 60. 



— miiltiflorum, 61. 

 Polygonum, 640. 



■ — dumetorum, 672. 



— fagopyrum, 283. 



— scandens, 668. 



— Sieboldi, 543, 685. 

 Poljpodium vulgare, 131. 

 Polyporus borealis, 388. 



■ — dryadeus, 388. 



— fulvtis, 388. 



— ignariuj, 388. 



— mollis, 389. 



— sulpbureus, 388. 



— vaporarius, 388. 

 Polysiphonia, 335. 



Poplar, 146, 186, 225, 229, 

 319, 578, 582, 584, 703. 



Populiis, iTj, 319. 



Porosity of wood, 238. 



Porous bodies, 243. 



Portulacca, 640. 



Position of reproductive 

 organs, 787. 



Positive geotropism, 679- 

 68r, 689-691, 703. 



— heliotropism, 693-695, 

 697, 703, 709, 712, 713, 

 714. 



— hydrotropism, 717. 

 Post-embryonic configura- 

 tion, 528. 



— growth, 503. 



influence of environ- 

 ment on, 516, 528, 536, 

 537. 



Potamogeton, 297, 701. 



■ — natans, 51. 



Potassium myronate, 342. 



— salts, 202, 226, 252, 260, 



262, 284, 287, 289, 290, 

 291, 320,383. 



— - — in sap, 274. 



— sulphate, 342. 

 Potato, 58, 330, 333, 337. 



— 59, 165, 169, 273, 274, 

 277, 278, 314, 316, 326, 

 333, 337, 339, 35o, 363, 

 369, 390, 504, 507, 535, 

 722, 798, 799. 



disease, 369, 381, 



Potent ill a, 780. 

 Precipitation membranes, 



214. 

 Pressureson sieve-tubes, &c., 



360. 



Pressures as a stimulus, 503, 

 515, 617. 



— and strains in cortex and 

 wood, 574-579- 



— in tissues, 362, 437, 581, 

 582. 



Prickles, 57, 125, 289. 

 Primary embryonic tissue, 

 417. 



— leaf, 747,764. 



— meristem, 419, 770. 



— root, 418, 689, 690, 703, 

 747, 752, 753, 764- 



— shoot axis, 747, 753. 

 Primordial leaf, 506. 

 Primrose, 186. 

 Primula auricula, 186. 



— elatior, 781. 

 — farinosa, 186. 



— marginata, 186. 



— officinalis, 781. 



— sinensis, 129, 184, 279, 

 790. 



184. 



Primulaceae, 780, 790. 

 Products of assimilation, 156, 



299, 314, 317, 357, 403, 



533, 763- 

 first visible, 306, 309, 



318. 



metamorphosesof,3 2 3. 



Products of degradation, 



328, 329. 



— of fermentation, 348. 



— of metabolism, 316, 323, 



330, 357. 

 Pro-embryo, 735, 764. 

 Progi-essive development, 



467, 468. 

 Propagation of stimuli, 596- 



598, 646, 649, 662, 



663. 



— vegetative, 477, 723, 798, 

 800. 



Properties of hybrids, 782- 

 784. 



— of parents transmitted to 

 off"spring, 779. 



— of wood, 234, 243. 

 Proportions of ash-constitu- 

 ents, 290. 



— of salts absorbed, 287. 

 Prosenchyma, 146. 

 Protandrous flowers, 792. 

 Proteaceae, 146. 

 Protection of growing-point, 



462. 



— of pollen, 797. 

 Proteid reserve-materials, 



332,345- 



substances in parasites, 



&c., 372. _ 



absorption of by insec- 

 tivorous plants, 374. 



