968 



Plant-formations, ii. 896. 

 Plant growth and crystal growth, i. 568. 

 Plant-lice, parthenogenesis, ii. 464. 

 Plant-members, fundamental forms, ii. 591. 

 Plant-migrations, nature of, ii. 904, 908. 

 Plants, a\)Sorption of organic matter, 1. 99. 



— adaptation to climatic conditions, i. 284. 

 to illumination, i. 384. 



to life in rapidly-flowing water, ii. 502. 



to life in very dry climate, i. 317. 



— advantages of alpine habit, ii. 510. 



— Alpine, absorptive cells, i. 90. 

 dwarf habit, i. 523. 



flowering and flowerless shoots, i. 652. 



protection of stomata by hairs, i. 292. 



with rolled leaves, reason for being 



generally evergreen, i. 304. 



— amphibious, characteristics, ii. 501. 

 transitional nature of, i. 75. 



— anatomy of, Nehemiah Grew's, i. 22. 



— and animals as a symbiotic community, i. 



254. 



— and animals, difference between, i. 504. 

 no boundary-line, i. 54 ; ii. 620. 



— and humble-bees as marauders, ii. 239. 



— and injurious quantities of minerals, ii. 



498. 



— and selective food-absorption, ii. 497. 



— anemophilous, ii. 129. 



— annual, and lack of moisture, ii. 500. 

 no scale-leaves, i. 623. 



origin of flower-stalk, ii. 737. 



— aquatic, characteristic of tissues, i. 424. 

 devoid of cuticle, i. 309. 



nourishment of, i. 56. 



pollen and pollination, ii. 105. 



spiny leaves, i. 438. 



— Arctic, with evergreen rolled leaves, i. 



304. 



— as agents in accumulation of various 



mineral substances, i. 261. 



— both anemo- and entoniophilous, ii. 328. 



— bulbous, and cold, i. 551. 



arrangement of leaves for rain, i. 94. 



distribution and habitats, i. 654. 



time of appearance in dry regions, i. 



318. 



— burning, i. 553. 



— carnivorous in minor degree, i. 155. 



number and classification, i. 119. 



spinous structures in pitfalls, i. 124. 



with adhesive apparatus, i. 153. 



— classes, orders, and genera of, i. 6. 



— classification, Linnean system, ii. 86. 



— classified from habitat, i. 55. 



— climbing, relative distribution, i. 671. 



— composed of cell aggregates, division of 



labour in, i. 269. 



— considered from point of view of descrip- 



tion and classification, i. 3. 



— defenceless, protected by others, i. 451. 



— distribution and heat, i. 527. 



— division of labour, i. 567. 



— effect of covering with earth, ii. 507. 



— entomophilous, ii. 129. 



— evolution, and classification, ii. 607. 



— fossil, agents in preservation, ii. 612. 



— freezing of, i. 539. 



— glabrous in the North of Europe become 



hairy in the South, i. 318. 



— grouping according to substratum, ii. 496. 



— heterophyllous, i. (368. 



— heterostyled, ii. 302. 



— influence of habitat on protection of 



stomata, i. 293. 

 of mutilation, ii. 515. 



— laud, absorption of carbonic acid, i. 3G8. 



— lithophytic. See Lithophytes. 



— luminous, i. 502. 



— main divisions, ii. 617. 



— maintenance of free passage for water 



vapomr in, i. 290. 



— mechanical changes effected by, i. 265. 



— metamorphosis of, compared to that of 



insects, i. 12. 



— multicellular, transportation of materials, 



i. 466. 



Plants, myrmecophilous, ii. 233. 



— Natural History of, by Theophrastus, 300 



B.C., i. 3. 



— of Arctic regions, not hairy, explanation, 



i. 316. 



— of steppes and prairies, varnish-like 



covering, i. 313. 



— on bark, nutrition of, i. 106. 



— parasitic, no root-cap, i. 764. 

 seedlings of, i. 173. 



— perennial, functions of roots, i. 781. 



— phyllogeny, views concerning, ii. 607. 



— poisonous, and odour, i. 431. 



— preservation in snow and ice, i. 262. 



— protection against animals, i. 430. 

 from freezing, i. 546. 



— resistance to cold, ii. 489. 



— resting condition, i. 512. 



— selection of food-salts, i. 69. 



— silica-loving, i. 74. 



— sleep of, i. 534. 



— spinose, i. 435. 



— stinging, and grazing animals, i. 442. 



— submerged, i. 668. 



absence of hairs, ii. 502. 



— succession and crowding-out of generation 



after generation, i. 268. 



of forms in steppes, Mediterranean 



district, and at Cape, with regard to 

 hairiness, :. 318. 



— succulent, extrusion of water by leaves, 



i. 271. 



fewness of stomata, i. 280. 



heat resistance, i. 554. 



majority have thick cuticle, i. 309. 



not eaten by animals, i. 432. 



time of appearance in dry regions, i. 



318. 



— summer sleep, i. 356. 



— swimming, i. 669. 



— symbiosis with ants, ii. 233, 243. 



— synthetic activity, i. 378. 



— thawing of, i. 542. 



— tuberous, and cold, i. 551. 



distribution and habitats, i. 654. 



— two main subdivisions, i. 592. 



— umbeUiferous, water receptacles, i. 156. 



— unicellular, absorption of food, i. 269. 

 transportation of materials, i. 466. 



— utilitarianism, i. 421. S^ 



— utilitarian view of, i. 1. 



— "viviparous", ii. 445. 



— wax on upper leaf-surfaces, i. 292. 



— weapons of, i. 432. 



— weaving, armature, i. 676. 



— winter resting, i. 5(32. 



— with cladodes, i. 333, 335. 



— with evergreen rolled leaves, conditions of 



life, i. 305. 



— with explosive flowers, ii. 268. 



— with rolled leaves, at Cape, localization of, 



i. 306. 

 wide distribution of, i. 303. 



— with sticky foliage, ii. 236. 



— with two-coloured leaves, habitats of, i. 293. 



— woody, time of appearance in dry regions, 



i. 318. 

 Plant-species, isolated colonies, i. 527. 

 Plant succession and substratum, ii. 498. 



— world and its history, ii. 3. 

 Plasmodia, behaviour towards light, i. 32. 



— food-absorption, i. 113. 

 Plasmodiophora Brassicje, ii. 619. 



galls on Brassica oleracea, ii. 522. 



Plasmopora viticola. See Peronospora viti- 



cola. 

 Plasticmaterials, solid, conduction and trans- 

 formation, i. 481. 



storing of, i. 479. 



withdrawal from leaves in autumn, i. 



Platanus, age, i. 720. 



— pollen storing and dispersion, ii. 146. 



— pollination, ii. 133. 



— protection of pollen, ii. 117. 

 Platanus orientalis, dimensions, i. 722. 

 Plate, nuclear, i. 581. 



Platycerium alcicorne, ii. 475. 



epiphytic, ii. 705. 



sterile and fertile fronds, ii. 476. 



Plectocomia elongata, inflorescence, i. 745. 

 Pleodorina, structure, ii. 633. 

 Pleurocarpous Moss, ii. 702. 

 Pleurococcaceaj, description, ii. 636. 



— symbiosis with animal and vegetable or- 



ganisms, ii. 637. 

 Pleurococcus vulgaris, structure, &o., ii. 636. 

 Pliny, Historia uaturalis, ii. 1. 



— plant-forms known to, ii. 600. 

 Ploner See, biological station, ii. 622. 

 Plum. See Prunns communis. 

 Plumbaginacea;, ii. 770. 



Plumbago capensis, sticky fruit, ii. 870. 

 Plumbago europsea, flower, ii. 236. 

 Plusia chrysitis, victim of Araujia, ii. 260. 

 Plusia precationis, victim of Araujia, ii. 260. 

 Poa, bulbils, ii. 818. 



— pollination, ii. 142. 



Poa alpina, plant with bulbils, ii. 445. 

 Poa annua, anthocyanin in glumes, i. 522. 



habit and elevation, ii. 512. 



Poa laxa, vertical range, ii. 746. 

 Pocket-galls, structure, ii. 531. 

 Pocket-plums, cause of, ii. 524. 

 Pod, nature of, ii. 432. 

 Podophyllum, anthocyanin, i. 484. 

 Podophyllum peltatum, emergence of leaf 

 from soil, i. 639. 



protection of pollen, ii. 127. 



Podosphaera, development of embryo, ii. 60. 

 Podostemacea;, ii. 757. 



— adaptation to environment, i. 424. 



— in rushing water, i. 79. 

 Poison, of stinging hairs, i. 441. 

 Poisons, protective, i. 431. 



Polar expeditions, temperature observations, 



i. 547. 

 Polarization, and ceU-wall, i. 568. 

 Polar nuclei, and endosperm formation, it 



421. 

 PolemoniaocEe, ii. 771. 



— autogamy in, ii. 384. 



— dichogamy in, ii. 312. 

 Polemonium, nectary, ii. 175. 

 Pollarding, object of, ii. 37. 

 Pollen, abortive, ii. 403. 



— amount in anemophilous plants, ii. 151. 



— and guidance to honey, ii. 248. 



— behavioiu' in cleistogamous flowers, ii. 392. 



— collection by insects, ii. 133. 



— contrivances for removal from anther, ii. 



359. 



— deposition, ii. 277, 280. 



— dispersal, ii. 103. 



— explosive ejection, ii. 137. 



— expulsion in certain Papilionacese, ii. 260. 



— foreign, possible influence in variation, ii. 



593. 



— insect food, ii. 167. 



— mixing on stigmas, ii. 403. 



— morphological value, ii. 85. 



— poverty in honey-bearing flowers, ii. 169. 



— prepotency of, ii. 406. 



— protection from rain and dew. ii. 107. 



— protection from wet, ii. 109, 121. 



— retention after deposition, ii. 282. 



— storage of, ii. 94, 146, 147. 



— times of discharge, ii. 142. 



— transference in Asclepiadaceae, ii. 257. 

 to insects, ii. 243, 247. 



— transport, by egg-laying insects, ii. 167. 

 direction of, ii. 136. 



Pollen-cell, division of contents in Coniferae, 

 ii. 420. 



efl'ect of wetting, ii. 106. 



Pollen-cells, differences in heterostyled 



flowers, ii. 405. 

 Pollen-grain, functional adaptations, ii. 103. 



germination in Gymnosperms, ii. 420. 



germination on foreign pistil, ii. 414. 



=microspore, ii. 478. 



Pollen-grains, ii. 98, 99. 



dimensions, ii. 97. 



formation, ii. 96. 



