INDEX, 



983 



Wedge-roots, of Loranthus Europsens, mode 



of growth, &c., i. 211. 

 Wedge-shaped apical-cell, i. 578. 

 Weepnig, 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, il. 726. 



West-Indian Sour-sop. See ^ nana muricata. 

 Wettstein, and anatomical characteristics of 



hybrids, ii. 565. 

 Wheat, seeds and heat, i. 555. 



— starch, i. 459. 



AVhite, visibility to insects, ii. 197. 



White Hellebore. See Veratrum. 



Wliite Mustard. See Sinapis alba. 



White-thorn. See Cratcsgus Oxyacantha. 



Whitlow-grass. See Draba. 



Whorl, of perianth-leaves, i. 641. 



Whorls, sorts of, i. 397. 



Whortleberry, Common. See Vaccinmm 



Myrtillus. 

 Wichura, hybridization of Willows, ii. 560. 

 Wigandia urens, stinging hairs, i. 441. 

 Wightia, clinging roots, i. 702, 754. 

 Wild Cress. See ^thionema. 

 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. 

 AVind, 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.l33. 

 Wind-polliuatio a, adaptation 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 Phii-'ialis Alkekenrji. 

 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 peotinata, ii. 526. 



on various trees, ii. 527. 



Wolffia, rootless, ii. 745. 



Wood, ascent of sap through, i. 274. 



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



— longitudinal splitting in twiners and 



climbers, i. 733. 



— "luminous", i. 502. 



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

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



gonaceous and Cruciferous plants, i. 74. 



Woodbine, Alpine. See Lonicera Alpigena. 



Wooden Pear. See Xylomelum pyriforme. 



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 Artemisia Ab- 



synthium. 

 Wormwoods, hairy covering in summer, i. 319. 

 Woundwort. See Stachys. 

 Wracks. See Fucacece. 

 Wrangelia, luminosity, i. 388, 



X. 



Xanthidium aculeatum, ii. 492, 655. 

 Xanthidium octocorne, ii. 492. 

 Xanthium, protogynous, ii. 313. 

 Xanthium spinosura, 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,'height, PI. XVI., ii. 731. 

 Xenogamy, in hybrids, ii. 583. 



— nature of, ii. 317. 



Xeranthemum, liairy covering in summer, i. 



319. 

 Xeranthemum annuum, coloured bracts, ii. 



183. 

 Xylaria Hypoxylon, ii. 679. 



stroma, ii. 681. 



Xylaria polymorijha, stroma, ii. 681. 

 Xylocopa violacea and Spartium scoparium, 



ii. 267. 

 Xylomelum pyriforme, fruit, ii. 430, 431, 751. 

 protecting pericarp, ii. 449. 



Yakutsk, winter cold, i. 544. 



Yeast fermentation, nature of, ii. 519. 



— ferment of, i. 465. 



Yeasts. See also Saccharomyees. 



— fermentative, i. 505. 



Yellow granules of autumn leaves, 1. 485. 

 Yellow-rattle. See Rhinaiithus Crista-galli. 

 Yellow Vetchliug. 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. 



— phyUotaxis, 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-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 Ustilago Maydis, ii. 524, 675. 



moncecious, 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. 

 Zingiberaceje, 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 Chlorophyce», ii. 628. 

 Zostera, i. 77. 



— habit, &c., i. 666. 



— pollen and pollination, ii. 104, 105. 

 Zostera marina, ii. 738. 



Zygsena, and honey scent, ii. 207. 

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



— characteristics, ii. 658. 



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



— conjugation, ii. 658. 

 Zygnema pectinatum, PI. I. 

 Zygnemacese, ii. 658. 



— chromatophores, ii. 654. 



— conjugation, ii. 55. 

 Zygnemese, filaments, i. 586. 

 Zygnemoideae, characteristics, ii. 654. 

 Zygogonium, nature of, ii. 54. 

 Zygomorphio symmetry, ii. 229. 

 Zygomycetes, characteristics, ii. 673. 

 Zygospore investment, in MortiereUese, 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 ChlorophyccLB, ii. 628. 



— of Conjugata;, 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 Phyllobium, ii. 638. 



— of Stephanospha;ra, &c., ii. 632. 



