INDEX, 



983 



Wedge-roots, of Loranthus EuropBBiia, mode 



of growth, &o., i. 211. 

 Wedge-ahaped apical-cell, i. 578. 

 Weeping, of plants, explanation, 1. 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. SeeAnonamuricata. 

 Wettstein, and anatomical characteristics of 



hybrids, ii. 565. 

 Wheat, seeds and heat, 1, 555. 



— starch, i. 459. 



White, Tisibility to insects, ii. 197. 

 White Hellebore. See Veratrum. 

 White Mustard. See Sinapis all^a. 

 White-thorn. See Cratmgus Oxyacantha. 

 Whitlow-gi-ass. See Draba. 

 Whorl, of perianth-leaves, i. 641. 

 Whorls, sorts of, i. 397. 

 Whortleberry, Common. See Vaccinium 



Myrtillus, 

 Wichura, hybridization of Willows, ii, 560. 

 Wigandia urens, stinging hairs, i. 441. 

 Wightia, dinging roots, i. 702, 754. 

 Wild Cress. See JSthionema. 

 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-graas. See Apera spicaventi. 



Wind-fertilized plants, characteristics, ii. 133. 



Wind-pollination,adaptationofBtigma,ii.l51. 



Wind-witches, ii. 850. 



Wine-cask Fungus, i. 508. 



Wine-flower scent, ii. 202. 



Wings of Papilionaceous flower, ii, 228. 



Winter-buds, of Aldrovaodia, i. 152. 



Winter Cherry. See PJi/ysalis 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. 



— "luminous", i. 502. 



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

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



gonaceous and Cruciferous plants, i. 74. 



Woodbine, Alpine. See Lonicera Alpigma. 



Wooden Pear. See Xylomelvm pyri/orme. 



Wood-parenchyma, i. 469- 



Woodruff. See Asperula odorata. 



Wood-sorrel. See Oxalis. 



Wood-vessels and cell, views regarding func- 

 tion, i. 376. 



Woody fibres, nature of, i. 726. 



Woody stem, characteristics, 1. 715. 



Woolly hairs, nature of, i. 320. 



Wormwood, Common. See Artemisia Ah- 



aynthium. 

 Wormwoods, hairy covering in summer, i. 319. 

 Woundwort. See Stachya. 

 Wracks. See Fucacece. 

 Wraugelia, luminosity, i. 388. 



X. 



Xanthidium aculeatum, ii. 492, 655. 

 Xanthidium octocorne, ii. 492. 

 Xanthium, protogynous, ii. 313. 

 Xanthium spinosum, and cattle, i. 451. 



fruits and dissemination, i. 615. 



hooked capitulum, ii. 873. 



Xanthophyll, from chlorophyll, i. 372. 

 Xanthorrhea, caudex, i. 714. 



— mode of growth, i. 659. 

 Xanthorrhea hastilis,iheight, PI. XVI. , ii, 731. 

 Xenogamy, in hybrids, ii. 583. 



— nature of, ii, 317. 



Xeranthemum, hairy covering in summer, i. 



319. 

 Xerantheipum annuum, coloured bracts, iL 



183. 

 Xylaria Hypoxylon, ii. 679. 



-^^ stroma, ii. 681. 



Xylaria polymorpha, stroma, ii. 681. 

 Xylocopa violacea and Spartium scoparium, 



ii. 267. 

 Xylomelumpyriforme, fruit, ii. 430, 431, 751. 

 protecting pericarp, ii. 449, 



Y. 



Yakutsk, winter cold, i, 544. 



Yeast fermentation, nature of, ii. 519. 



— ferment of, i. 465. 



Yeasts. See also SacoJiaromyces. 



— fermentative, i. 505. 



Yellow granules of autumn leaves, i. 485. 

 Yellow-rattle. See Rhinanthiis Crista^alli. 

 Yellow Vetchling. See Lathyrus Aphaca. 

 Yew. See Toxwa baccata. 

 Ylang perfume of Zalxizianskia, 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. 



— polliuation by Pronuba yuccasella, ii. 157, 



245. 



Yucca aloefolia, fertilization, ii. 158, 159. 



fertilization, geographical distribution, 



ii. 159. 



Yucca angustifoUa, pollen-grains, ii. 97. 



Yucca gloriosa, i. 659 ; ii. 732- 



Yucca Treculeana, fertilization and geo- 

 graphical distribution, ii. 159. 



Yucca Whipplei, non-fruiting, ii. 158. 



z. 



Zaluzianskia lychnidea, pollination and 



scent, ii. 202, 241. 

 Zamia, cotyledon in germination, i. 606. 



— spiny leaves, i. 438. 

 Zannichellia, monoecious, ii. 297. 



— pollen and pollination, ii. 105. 



— root origin, i. 766. 

 Zanthoxylon, reserve-buds, ii. 32. 



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



moQcecious, ii. 297. 



protogynous, ii, 313. 



stilt-roots, mechanical tissue, i. 762. 



vitality of spermatoplasm, ii. 96. 



Slc, reared in artificial culture solu- 

 tion, i. 100. 

 Zero of growth, i. 561. 

 Zigzag stem, i. 658. 

 Zingiber, venation, i. 634. 

 Zingiberaeese, stamens, ii. 736. 

 Zinnia hybrida, 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 Chlorophycese, ii. 628. 

 Zostera, i. 77. 



— habit, &c., i. 666. 



— pollen and poUination, ii. 104, 105^ 

 Zostera marina, ii. 738, 



Zygaena, and honey scent, ii. 207. 

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



— characteristics, ii. 658. 



— chlorophyll bodies, cf. PI. I., i. 373. 



— coniugation, ii. 658. 

 Zygnema pectinatum, PI. I. 

 Zygnemacese, ii. 658, 



— chroraatophores, ii. 654. 



— conjugation, ii. 55. 

 Zygnemeae, filaments, i. 586. 

 Zygnemoidese, characteristics, ii. 654. 

 Zygogonium, nature of, ii. 54. 

 Zygomorphic symmetry, ii. 229. 

 Zygomycetes, characteristics, ii. 673. 

 Zygospore investment, in Mortierellese, 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 Chlorophycese, 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 Ulothrix zonata, ii. 648. 

 Zygozoospore, formation, ii. 632. 

 Zygozoospores, of Chlorochytrium, ii. 637. 



— of PhyUobium, ii. 638. 



— of Stephanosphjera, &c., ii. 632. 



