INDEX. 



983 



Wedge-roota, of Loranthua EuropBeuB, mode 



of growth, &c., i. 211. 

 Wedge-shaped apical-cell, i. 578. 

 Weeping, of plants, explanation, i. 271. 



— in Aroid roots, i. 366. 



— of Vines, when most vigorous, i. 270. 

 Wellingtonia. See Sequoia gigantea. 

 Welwitschia mirabilis, in habitat, ii. 727. 



geographical distribution, ii. 726. 



West-Indian Sour-sop. See Anona muricata. 

 Wettstein, and anatomical characteristics of 



hybrids, ii. 565. 

 Wheat, seeds and heat, i. 555. 



— starch, i. 459. 



White, visibility to insects, ii. 197. 

 White Hellebore. See Verati-um. 

 White Mustard. See Sinapis alba. 

 White-thorn. See Crutcegus Oxyacantka. 

 Wliitlow-grass. See Drdba. 

 Whorl, of perianth-leaves, i. 641. 

 Whorls, sorts of, i. 397. 

 Whortleberry, Common. See Vacdnium 



Myrtilliis. 

 Wichiu^, hybridization of Willows, ii. 560. 

 Wigandia urens, stinging hairs, i. 441. 

 Wightia, clinging roots, i. 702, 754. 

 Wild Cress. See jStkionema. 

 Wild Pear, spines, i. 433. 

 Will-o' -the- Wisp, and luminous mycelium, I. 



503. 

 Willow. See Salix. 

 Willow, Gray. See Salix incana. 

 Willow-herb. See Epilobium. 

 Willows, Alpine, Tyrol, i. 524. 

 Wind, agent in spore-dispersal, ii. 812. 



— and fruit boring, i. 618. 



— and position of leaves, i. 427. 



— and seed dispersal, ii. 447. 



— and stunted growth, i. 524. 



Wind Bent-grass. See Apera spicaventi. 

 Wind-fertilized plants, characteristics, ii. 133. 

 Wind-pollination,adaptat;on of stigma, ii. 151. 

 Wind-witches, ii. 850. 

 Wine-cask Fungus, i. 508. 

 Wine-flower scent, ii. 202. 

 Wings of Papilionaceous flower, ii. 228. 

 Winter-buds, of Aldrovandia, i. 152. 

 Winter Cherry. See Physalis Alkekengi. 

 Winter-green. See Pyrola. 

 Winter resting of plants, i. 562. 

 Witches' Brooms and Exoascus, ii. 676. 



caused by gall-mites, ii. 548. 



cause of, ii. 518. 



on Abies pectinata, ii. 526. 



on various trees, ii. 527. 



Wolffia, rootless, ii. 745. 



Wood, ascent of sap through, i. 274, 



— changes due to attack of hyphae, i. 167. 



— longitudinal splitting in twiners and 



climbers, i. 733. 



— "luminoxis", i. 502. 



— of host, effect of Langsdorffia on, i. 187. 

 Wood-ash, effect on Mosses, Grasses, Poly- 



gonaceous and Cruciferous plants, i. 74. 



Woodbine, Alpine. See LoniceTa Alpigena. 



Wooden Pear. See Xylomelum pyriforrm. 



Wood-parenchyma, i. 469. 



Woodruff. See Asperula odorata. 



Wood-sorrel. See Oxalis. 



Wood-vessels and cell, views regarding func- 

 tion, i. 276. 



Woody fibres, nature of, i. 726. 



Woody stem, characteristics, i. 715. 



Woolly hairs, nature' of, i. 320. 



Wormwood, Common. See Artemiaia Ab- 



synthium. 

 Wormwoods, hairy covering in summer, i. 319. 

 Woundwort. See Stachys. 

 Wracks. See FucaceiB. 

 Wraugelin, luminosity, i. 388. 



X. 



Xanthidium aculeatum, ii. 492, 655. 

 Xanthidium octocorne, ii. 492. 

 Xanthium, protogynous, ii. 313. 

 Xantbium spinosum, and cattle, i. 451. 



fruita and dissemination, i. 615. 



hooked capitulum, ii. 873. 



Xanthophyll, from chlorophyll, i. 372. 

 Xanthorrbea, caudex, i. 714. 



— mode of growth, i. 659. 

 Xanthorrhea hastilis, height, ii. 731. 

 Xenogamy, in hybrids, ii. 583. 



— nature of, ii. 317. 



Xeranthemum, hairy covering in summer, i, 



319. 

 Xeranthemum annuum, coloured bracts, ii. 



183. 

 Xylaria Hyposylon, ii. 679. 



stroma, ii. 681. 



Xylaria polymorpha, stroma, ii. 681. 

 Xylocopa violacea and Spartium scoparium, 



ii. 267. 

 Xylomelum pyrif orme, fruit, ii. 430, 431, 751. 

 protecting pericarp, ii. 449. 



Yakutsk, winter cold, i. 544. 



Yeast fermentation, nature of, iL 519. 



— ferment of, i. 465. 



Yeasts. See also Saccharomyces. 



— fermentative, i. 505. 



Yellow granules of autumn leaves, i. 485. 

 YeUow-rattle. See Rhinanthus Crista^alli. 

 Yellow Vetchling. See Lathyrus Aphaca. 

 Yew. See Taxus baccata. 

 Ylang perfume of Zaluzianskia, ii. 242. 

 "York and Lancaster" Rose, ii. 568, 

 Yucca, acicular leaves, i. 434. 



— and insect visits, ii. 222. 



— and night visitors, ii. 196. 



— caudex, i. 714. 



— cotyledon in germination, i. 606. 



— fertilization by Moths and advantage to 



the insects, i. 255. 



— infertility in Europe, ii. 403. 



— mode of growth, i. 660. 



— phyllotaxis, i. 402. 



- pollination by Pronuba yuccasella, ii. 157, 

 245. 



Yucca aloefolia, fertilization, ii. 158, 159. 



fertilization, geographical distribution, 



ii. 159. 



Yucca angustifolia, pollen-grains, ii. 97. 



Yucca gloriosa, i. 659 ; ii. 732. 



Yucca Treculeana, fertilization and geo- 

 graphical distribution, ii. 159. 



Yucca Whipplei, non-fruitiug, ii. 158. 



Zaluzianskia lychnidea, pollination and 



scent, ii. 202, 241. 

 Zamia, cotyledon in germination, i. 606. 



— spioy leaves, i. 438. 

 Zannichellia, monoecious, ii. 297. 



— pollen and pollination, ii. 105. 



— root origin, i. 766. 

 Zanthoxylon, reserve-buds, ii, 32. 



Zea Mays, and TJstUago Maydis, ii. 524, 675. 



monoecious, ii. 297. 



protogynous, ii. 313. 



stilt-roots, mechanical tissue, i. 762. 



vitality of spermatoplasm, ii. 96. 



&c,, reared in artificial culture solu- 

 tion, i. 100. 

 Zero of growth, i. 561. 

 Zigzag stem, i, 658. 

 Zingiber, venation, i. 634. 

 Zingiberacese, stamens, ii. 736. 

 Zinnia by brida, colour-contrast in capitulum, 



ii. 191. 

 Zonotrichia, in waterfalls, i. 79. 



— movement of, i. 39. 



Zoogloea, bacterial condition, ii. 622. 



— of Micrococcus prodigiosus, ii. 624. 

 Zoophytes, appropriateness of name, ii. 469. 

 Zoospore, eye-spot, ii. 629. 



— of Botrydium, ii. 642. 



— of Vaucheria, ii. 644. 



Zoospore formation, in Hydrodictyon, ii. 641. 

 Zoosporese, ii. 606, 

 Zoospores, ii. 17. 



— behaviour towards light, i. 382. 



— of Cblorophycese, ii. 628. 

 Zostera, i. 77. 



— habit, &c., i. 666, 



— pollen and pollination, ii. 104, 105. 

 Zostera marina, ii, 738, 



ZygEena, and honey scent, ii. 207, 

 Zygnema, cell-division, i. 577, 581. 



— characteristics, ii. 658. 



— chlorophyll bodies, cf. i. 139, 373. 



— conjugation, ii. 658. 

 Zygnema pectinatum, i. 139. 

 Zygnemaceae, ii. 658. 



— cbromatophores, ii. 654. 



— conjugation, ii. 55. 

 Zygnemeae, filaments, i. 586. 

 ZygnemoideEB, characteristics, ii. 654. 

 Zygogonium, nature of, ii. 54. 

 Zygomorphic symmetry, ii. 229. 

 Zygomycetes, characteristics, ii. 673. 

 Zygospore investment, in Mortierelleie, ii, 674, 



— of Mucor, ii. 673. 



— of Mucorini, ii. 481. 484, 

 Zygote, nature of, ii. 54, 



— of Botrydium, ii, 642, 



— of Chlorochytrium, ii. 637. 



— of Cblorophyceae, ii. 628. 



— of Conjugatse, ii. 654. 



— of Desmids, ii. 654. 



— of Hydrodictyon, ii. 641. 



— of Pediastrum, ii. 639. 



— of Phyllobium, i. 638. 



— of Spirogyra, ii, 658. 



— of Volvox globator, ii. 635, 

 Zygotes of TTlothrix zonata, ii. 648. 

 Zygozoospore, formation, ii. 632. 

 Zygozoospores, of Chlorochytrium, ii. 637. 



— of Phyllobium, ii. 638. 



I — of Stephanosphaera, &c., ii. 632. 



