964 



Nigella, nectaries, ii. 179. 



Nigella arvensis, effect of mutilation, li. 



517. 

 Nigella Damascena, styles, i. 645. 

 Nigella elata, honey-leaf, ii. 180. 

 Nigella sativa, honey-leaf, ii. 180. 

 Night-flowers, ii. 213. 

 Nightshade, Alpine Enohantei-'s. See Circcea 



alpina. 



— sceut, ii. 202. 



Nigritella, position of labellum, ii. 224. 

 Nigritella nigra, scent, ii. 201. 

 Nigritella suaveolens, hybrid, ii. 563, 586. 



hybrid, colour of flowers, ii. 567. 



Nipple-wort. See liapsana. 

 Nissolia, phyllodes, i. 335. 

 Nitella, characteristic feature, ii. 661. 

 Nitella syncarpa, freezing, i. 540, 542. 

 Nitric acid, agent in weathering, i. 83. 



earliest source, i. 64. 



reduction, i. 458. 



sources of, i. 83. 



Nitrification of soil, by Bacteria, li. 624. 

 Nitrogen, i. 258. 



— fixation by Bacteria, ii. 624. 



— in albumen, i. 457. 



— non-accumulation from hydrophytes, i. 



261. 



— percentage in air, i. 64. 



— replacing hydrogen, i. 454. 



— sources of, i. 64, 457. 



Nitrogenous compounds, not respired di- 

 rectly, i. 495. 



probably obtained by water-absorbing 



aerial organs, i. 241. 

 Nitrogenous matter, effect on glands of 



Drosera. i. 144. 

 Nodding of flowers, and protection of 



pollen, ii. 119. 

 Nodes, of stem, i. 396, 658. 



— relation of hairs to, in Stellaria media, i. 



227. 

 Noea spinosissima, spinosity, 1. 444. 

 Nolanacese, ii. 771. 

 Nonnea, pollen-grains, ii. 99. 

 Non-saprophytes, on trees, i. 106. 

 Norway Maple. See Acer platanoides. 

 Nostoc and CoUema, ii. 694. 



— association with other plants, ii. 622. 

 Nostoc edule, ii. 621. 



Nostocacese, as Lichen-algse, ii. 692. 



— description, ii. 621. 



— filaments, i. 586. 



— habit, i. 589. 



Nostocineie, lime incrusted, i. 260. 



— loss of bulk through loss of water, i. 216. 

 Notochlsena Marantse, rolling up of frond, i. 



314. 

 Nottingham Catchfly. See Silene nutans. 

 Nucellus, of ovule, ii. 72, 81, 644. 

 Nucleus, of cell, and starch -formation in 

 Spirogyra, ii. 657. 



central organ, i. 53. 



composition, &c., i. 41. 



functions, ii. 493. 



importance of, i. 48. 



in streaming protoplasm, i. 34. 



structure, i. 569. 



structure and division, i. 580, 581. 



— of ovule, i. 644. 



— of starch grain, i. 460. 

 Nullipores, fossil Floridese, ii. 614. 

 Nuphar, ovary, ii. 75. 



— position of stomata on leaves, i. 280. 

 Nuphar intermedium, fertility, ii. 590. 



Nuphar luteum and N. pumilum, hybrid, 



ii. 558, 589. 

 Nutating tendrils, i. 696. 

 Nutation, of roots, i. 774. 



— of twining stems, i. 683. 

 Nut, embryo protection, ii. 450. 



— nature of, ii. 429. 



" Nut-cracker" and Walnut, &c., ii. 440. 

 Nutmeg. See Myristica mosc?iata. 

 Nutrition and gamete-formation, ii. 641. 



— and sexual organs of Vaucheria, ii. 644. 



Nutrition, mode of, best determined by 

 artificial cultures, i. 104. 



— of plants, mutation, translocation, &c., of 



substances concerned in, i. 258. 

 Nux-vomica, cells from seed, i. 45. 

 Nyctaginacese, calcium oxalate crystals, i. 570. 



— perianth, ii. 749. 



— pollen-grains, ii. 97, 102. 

 Nyctaginese, ii. 196. 



Nyctandra, dehiscence of pollen-sacs, ii. 93. 



— stamen, ii. 91. 



Nymphaea, floating fruits, ii. 848. 



— leaf and transpiration, i. 288. 



— position of stomata on leaves, i. 280. 



— protection of pollen, ii. 113. 

 Nymphsea alba, ash of, i. 69. 



contrivance for getting rid of rain- 

 water, i. 288. 



habit and habitat, ii. 511. 



latitude and closing, ii. 218. 



pollen-grains, ii. 99, 100. 



Nymphsea cosrulea, scent, ii. 201. 

 Nymphsea Devoniensis, size of flowers, ii. 



185. 

 Nymphsea gigantea, size of flowers, ii. 185. 

 Nymphaea guianensis, epiphyllous buds, ii. 



43. 

 Nymphffia Lotus and N. dentata, hybrid and 



sepals, ii. 576. 



anthooyanin, i. 521. 



Nymphsea thermalis, anthocyanin, L 521. 

 Nymphseacese, anther, ii. 90. 



o. 



Oak. See Quercus. 

 Oak-apples, nature of, ii. 528. 

 Oak-galls, various, ii. 541. 

 Oak-leaves, galls on, ii. 552. 

 Oat. Se& Avena sativa. 

 Oats, pollination, ii. 142. 



— starch, i. 459. 



Obione haUmifolia, "deaf" fruits, ii. 468. 



Ochna, flower and fruit, ii. 778. 



Ochrus, phyllodes, i. 335. 



Ocyraum and cold, i. 545. 



Ooymum Basilicum, pericarp mucilage, i. 



615. 

 Odontidium hiemale, in spring above Arzler 



Alp, i. 71. 

 Odontites, parasitic, i. 176. 

 Odontites lutea, culture experiment, i. 180. 

 Odontoglossum, edible fleshy growths, i. 170. 

 Odontoglossum Eossii, duration of flowering, 



ii. 214. 

 Odour, and poisonous properties, i. 431. 

 Odours, variety in a genus, &c., ii. 487. 

 Qidogoniacese, ii. 650. 

 ffidogonium and Chytridium Olla, ii. 669. 



— chlorophyll body, i. 373. 



— life-history, ii. 650. 

 OEnanthic acid, ii. 202. 

 ffinothera, and insect visits, ii. 223. 



— downward pull of roots, i. 767. 



— moths and pollen, ii. 247. 



— opening of flower, ii. 212. 



— stigma, ii. 283. 



Oenothera biennis, autogamy, ii. 253. 



flower, ii. 247. 



inflorescence, ii. 282. 



pollen-grains with viscin threads, ii. 101. 



Oenothera grandiflora, opening of flower, ii. 



212. 

 Oenothera muricata, autogamy, ii. 253. 

 Offshoots, ciUated, ii. 802. 



— dispersal by water, ii. 805. 



— fonnation and climatic conditions, ii. 453. 



— on runners, ii. 801. 



— propagation by, ii. 790. 

 Oil, of bitter almonds, i. 462. 



— of cloves, ii. 200. 



— of Neroli, source, ii. 203. 



— of turpentine, lavender, &c., i. 461. 

 Oken, nature-philosophy (1810), i. 13. 

 Olaoacese, ii. 754. 



Old Man's Beard Lichen. See Usnea barbata. 



Old World, hairiness of plants on steppes and 



deserts, i. 317. 

 OleacesB, ii. 771. 



Oleander. See Nerium Oleander. 

 Olfactory organs, in man and animals, ii. 204. 

 Olive grove on the shores of Lake Garda, i. 



275. 



— oil, decomposition, i. 462. 

 Olive-tree, stomata, i. 280. 

 Ombrophytum, appearance and dimensions, 



i. 196. 



— Peruvian name, i. 19G. 



Omphalia, in salt-mine at Hallstatt, i. 101. 

 Omphalodes verna, flower colour and sur- 

 roundings, ii. 194. 

 Onagraceie, ii. 781. 



— pollen-grains, ii. 99, 102. 

 Oncidiura, aerial roots, i. 222, 753. 



— edible fleshy growths, ii. 170. 

 Oncidium Papilio, ii. 224. 



animal mimicry, ii. 229. 



Onion. See Allium. 



Onobrychis, insects and keel movements, ii. 



252. 

 Onobrychis sequidentata,hooked fruit, ii. 873. 

 Onobrychis cornuta, spinosity, i. 444. 

 Ononis, pollen expulsion, ii. 260. 

 Onopordon, method of water-conduction, i.96. 



— movements of stamens, ii. 252. 



— protection of jiollen, ii. 126. 



— spiny leaves, i. 438. 

 Onosma, bristles, i. 441. 

 Ontogeny and phyllogeny, ii. 608. 

 Oogonia, of Achlya lignicola, ii. 671. 

 Oogonium, definition, ii. 47. 



— of Fucus vesiculosus, ii. 663. 

 Oomycetes, characteristics, ii. 668. 

 Oophyte, of Pteridophyta, characteristics, ii. 



704. 

 Ooplasm, protection in Phanerogams, ii. 72. 

 Ooplast, of Phanerogams, ii. 81. 

 Oospheres, of Chlorophycese, ii. 628. 

 Oospore, of Chlorophycefe, ii. 628. 

 Opegrapha lithyrga, habitat, i. 117. 

 Opera Girl. See Mantisia. 

 Operculum, of Moss capsule, ii. 702. 

 Ophelia, nectaries, ii. 178. 

 Ophioglossaceie, characteristics, ii. 709. 



— two kinds of fronds, ii. 12. 

 Ophioglossum vulgatura, radical buds, ii. 28. 

 Ophrys cornuta, flower, ii. 226. 



insect platform, ii. 227. 



Opium, latex of Papaver somniferum, i. 470. 

 Opium Poppy. See Papaver somnifenim. 

 Opoponax Cretica, seed-dispersal, ii. 853. 

 Opuntia, insect platform, ii. 229. 



— irritable staminal filaments, ii. 264. 



— opening of flower, ii. 212. 



— protection of pollen, ii. 113. 



— spines, i. 446. 



— stem structure, i. 327. 



Opuntia nana, recurrent opening, ii. 213. 



stigma, ii. 279. 



Opuntia Rafinesquii, barbed bristles, i. 439. 

 Orache. See Atriplex. 

 Oraches, and animals, i. 432. 



— trimethylamine, i. 462. 

 Orange-flower scent, ii. 203. 



Orange Lily. See Lilium croceum and L. 



bulbi/irum. 

 Orange-tree, odours, i. 461. 

 Orchid inflorescence, position of flowers to 



axis, ii. 256. 

 Orchidacese, characteristic of flower, ii. 736. 



— cleistogamy in, ii. 393. 



— epiphyllous buds, ii. 43. 



— hybrids among, ii. 583. 



— ovary, ii. 77. 



— pollination, details, i: 



— subdivisions, ii. 736. 

 Orchids, anther, ii. 93. 



— aqueous tissue, i. 328 



— chlorophyll in roots, : 



— chlorophyll in seeds, &c., i. 376. 



— conducting tissue for pollen-tubes, ii. 41ft 



— cross-fertilization, ii. 302. 



— cylindrical leaves in, i. 327. 



253. 



.766. 



