None
Pfliiger ; Archiv fur die gesammte Physiologic, xxxn, 1883, p. 65. Pringsheim; Neue Beobachtungen lib. d. Befruchtungsact von Achlya und Saprolegnia, Sitzber. d. Berl. Akad. 1882 : also, Pringsheim's Jahrbiicher f. wiss. Bot, xiv. de Bary ; Beitrage zur Morphologic und Physiologic d. Pilze, IV, 1 88 1 ; also Vergleichende Morphologic und Biologic der Pilze, Leipzig, 1884. Balfour ; Comparative Embryology, Vol. I, p. 78. Zacharias ; Berichte d. deutsch. bot. Gesellschaft, III, 1885. Minot ; Proc. Boston Soc. nat. hist., Vol. XIX, 1877. van Beneden ; Recherches sur la maturation de 1'oeuf, etc., Bull, de 1'Acad. roy. de Belgique, seV. 2, t. XL, 1875, t. XLI, 1876. Brooks ; loc. tit. p. 102. Darwin ; Origin of Species, 6th ed., 1872, p. 106. Darwin ; Variation, Vol. II, p. 242. Kolreuter ; Vorlaufige Nachricht von einigen das Geschlecht be- treffenden Versuchen und Beobachtungen, Dritte Fortsetzung, Leipzig, 1766. Gartner ; Bastarderzeugung, p. 249. Gartner; Bastarderzeugung, pp. 445, 513. Wichura; Die Bastardbefruchtung im Pflanzenreich, Breslau, 1865. Darwin ; Origin of Species, p. 107. Darwin ; Variation, Vol. II, p. 265. INDEX. Abies pectinata, heliotropism of leaves of, 444 Absorption of; ammonia, by leaves, 86 ; carbon dioxide in light (Figs. 17, 18), 8r, 142 ; gases by leaves, 72 ; influence of pressure on, 73; nitrogen, 85; oxygen, 77; salts, 55; substances in- soluble in water, 54; water by leaves, 65 ; water and substances in solution by roots (Figs. 10, n), 46; influence of metabolism on, 53; influence of temperature on, 52 ; relation of tran- spiration to, no, 115 Absorption, Law of, 57 Acacia Farnesiana, nyctitropic move- ment of, 540 Acer, calcium oxalate in, 22 Acetabularia, life-history of, 632 ; re- production of, 607 Achlya, reproduction of, 620 Achromatin, 27 Acidity of roots, 55 Acids in plants, metabolism, 225 ; rela- tion to turgidity, 41, 391, 580 Acrylcolloid, 31 Adaptation, 677 Adhesive discs of tendrils, 411 Adoxa moschatellina, Diageotropism of rhizomes of, 501 Aecidia, 624 Aecidiospores, 624 Aethalium, proteids in, 25 ; reaction to stimuli, 527; killed by high tempera- ture, 279 Aerobia, 211 Aesculus Hippocastanum, geotropic cur- vatures in, 465 ; sensitiveness of root- tips, 493 Agapanthus timbellatus, diageotropism of pedicel of, 463 Agaricus melleiis^ luminosity of, 316; olearius, luminosity of, 316 Aggregation» 564 Air-roots, 50; of Orchid (Fig. 12), Air, composition of, 74; solubility of component gases in water, 74 Alcannin, 239 Alcoholic fermentation, 208 Aldehydes, 236 Aldrovanda, conduction of stimulus in leaf, 587; movements of leaf, 545 Aleurone grains, 25, 170; composition of, 184; structure of (Fig. 28), 183 Algse, life-history of, 631 ; sexual repro- duction in, 605 (Figs. 65, 66, 67, 69) Alizarin, 238 Alkaloids, origin of, 22,3, 268 Allantoin, 221 Allassotonic movements, 533 A Ilium sativum, heliotropism of, 428 A Ilium ursimim, fixed light-position of leaf of, 445 Aloin, 243 Alternation of Generations, 628 Amici, on relation of stomata to light, 107 Amides, 150, 221 Ammonia, absorption of, by leaves, 86 ; by roots, 127; formation in plants, 150, 223 Amoeboid movements, relation of, to oxygen, 297; to temperature, 298; mechanism of, 558 Amphicarp&a monoica, paraheliotropism of leaf of, 552 Amyloplasts (Fig. 26), 26, 180 Analysis of plants, 121 Anaerobia, 211 Anaesthetics, action of, on mature motile organs, 550 Ancylistese, reproduction of, 618 Ancistrocladus, hooks of, 412 Angiosperms, reproduction of (Figs. 70, 75). 6l5 Angle of deviation, 421, 503 Anisotropic organs, 424 Annual rings, 351 Annuals, 597 Anonaceae, 412 684 INDEX. Antheridium, 609 Antherozoids, 609; attraction of, by malic acid and cane sugar, etc., 529 Anthocyanin, 242 Antholeucin, 242 Anthoxanthin, 242 Antidromous torsion, 514 Aphanomycesscaber, parthenogenesis in, 620 Apheliotropism, 428 Apogamy, parthenogenetic, 605, 636; vegetative, 602, 636 Apogeotropism, 458 Apospory, 601, 636 Apostrophe, 299, 527, 592 (Fig. 36) Apothecium, 622, 625 Apposition, 16; theory of growth, 337 Aqueous vapour, condensation of, by soil, 48 ; by velamen of Orchids, 50 Archegonium, 610; of Moss (Fig. 68), 611 Archicarp, 621 Arendt, analysis of oat plants, 63, 1 29 Aromatic acids, 235 ; substances, 232 Artabotrys, hooks of, 412 Artificial cells (Traube), 42 Arum, evolution of heat by spadix of, 304 Ascobolus, sexual organs (Fig. 74), 623 Ascogenous hyphse, 622 Ascogonium, 622 (Fig. 73) Ascomycetes, reproduction, 620 Ascospores, 621 Ascus, 621 Ash of plants ; analysis of, in Brassica okracea (Pierre), 62; in species of, Fucus (Gb'dechens), 61 ; in oat plants (Arendt), 63, 129; in varieties of potato (Herapath), 62; after addition of salts to soil (Wolff), 64; com- parison of, 64; in clover (Hellriegel), 131 ; silica in, 60 Askenasy — on colours of flowers of etiolated plants, 267 on simultaneous growth of inter- nodes, 339 on absorption of heat by leaves, 314 Asparagin, 150, 174, 221 Aspidiumfalcatum, and Aspidium Filix mas, apogamy of, 60 1 Asplenium, see Athyrium Athyrium Filix fcemina, apospory, 601; adventitious buds on leaves of, 599 Atkinson, on diastatic ferment, 193 Atriplex latifolia, heliotropism of, 441 ; geotropism of, 469 Aulacomnion androgynum, gemmae of, 599 Automatism, 7, 373 Auxanometer (Fig. 44), 399 Auxotonic movements, 533, 573 Avena sativa, localisation of heliotropic irritability in, 438 Averrhoa bilimbi, tracing of nyctitropic movements of (Fig. 58), 540 Azygospores, 618 Bacillus, formation of spores in, 602 Bacteria, as tests for oxygen (Engel- mann), 256 Bacterium photometricum, influence of light on movements of, 298, 523, 574 Baeyer, on decomposition of carbon di- oxide, 144 Bailey, on crystalloids in potato, 171 Balfour, on extrusion of polar body, 669 Balsams, 236 Bangiacese, reproduction of, 613 Banks, on transpiration in its relation to the stomata, 107 Baranetzky — on transpiration, 1 1 3 on climbing stems, 510 on diastatic ferment (Fig. 28), 183, 189 on growth in length (Fig. 685 Batalin— on growth of leaves in darkness, 38i on movements of growing leaves, 405 on movements of leaf of Oxalis, 538 Batrachospermum, 613 Becquerel, on temperature of trunks of trees, 315 Begonias, propagation of, 598 Belajeff, on development of anthero- zoids, 639 Bellamy, on alcoholic fermentation, 209 Beneden, E. van, on extrusion of polar body, 672 Berberis, irritable stamens of, 533, 545, 548» 559 Berard, on alcoholic fermentation in fruits, 209 ; on Carnauba wax, 244 Bergrnann, on presence of formic and acetic acids in plant -cells, 225 Bert— on effect of variations in the atmo- spheric pressure, 74 on evolution of heat accompanying movements of Mimosa, 312 on motile organs, 312 on condition of movements of Mi- mosa, 537, 539, 541, 544, 549, 572 Berthelot, on the formation of com- bined nitrogen, 128 Berthold, on reproduction of Ectocar- pus, 608 (Fig. of water by leaves, 66 on assimilation of carbon by plants, 146 on analysis of maize seeds, 1 76 on chemical action of roots on so- lutions, 56 on effect of excess of carbon dioxide on absorption by leaves, 73 on evolution of hydrogen by plants, 209 on evolution of oxygen, 142 on excretion by roots, 222 on exhalation of carbon dioxide by leaves, 198 on formation of non-nitrogenous organic substances in plants, 147 686 INDEX. Boussingault— on germination at low temperature, 271 on loss of weight by plant in respiration, 195 on radiation, 313 on relation of phosphates to assi- milation of nitrogen, 132 on weight of plant in light, 253 Bower, on apospory, 60 1 Braconnot, on excretion by roots, 222 Brassica oleracea, analysis of ash of (Pierre), 62 ; galvanotropism of, 474 Braun — on the oogonium of the Characese, 642 on torsion, 354 Brefeld— on alcoholic fermentation, 208, 213 on Basidiomycetes, 625 on destructive metabolism, 292 on etiolation of Fungi, 393 on luminosity, 318 Brewster, on luminous Algae, 317 Briosi— on oil-drops in Musacese, 146 on starch-grains in sieve-tubes, 166 Brongniart, on transpiration, 103 Brooks— on function of male and female cells, 656, 673 on parthenogenesis, 674 on theory of Pangenesis, 655 on transmission of variability by male cell, 656, 676 Broughton — on evolution of carbon dioxide from seedlings, 200 on relation of alkaloids to nitro- genous food, 224 Brown, on action of diastatic ferment, 191 Briicke, on movement of Mimosa, 560 Brunchorst, on localisation of geotropic irritability, 468 Buff, on electrical condition of plants, 3i9' 3^2 Bunsen — on formation of compounds of nitrogen, 128 on photochemical induction, 263 Burnett and Mayo, on Mimosa, 560 Butlerow, on formation of methylenitan, 144 Burgersteln — on the Darwinian curvature, 495 on transpiration, 109, 1 10 Bryophyllum, vegetative budding in, 599 Bryopsis, 9 Bryum annotinum, bulbils of, 599 Buds, 599 Bulb, 599 Bulbils, 599 Cahours, on exhalation of carbon di- oxide increased by light, 260 Calamus rotang, silica in, 21 Calcium, as a constituent of the food, 134; carbonate deposited in cells, 22, 249; excretion of, 246; oxalate, 22, 231, 249; in cell-wall, 22 Callus, formation of, on wounds, 333 ; in sieve-tubes, 166 Calyptra, 626 Calystegia, twining of, 491, 511, 517 Cambium layer, 347 Cameron, on absorption of urea by roots, 124 Campanula persicifolia^ heliotropism of leaves of, 444 de Candolle — on conductivity of woods, 316 on excretion by roots, 222 on germination in low temperature, 269, 272 on heliotropism, 439 on plants as affected by high tem- perature, 279 on spontaneous movements of varia- tion, 537 Caoutchouc, 237 Carbohydrate; formation of, 140; de- composition of, 228; as reserve mate- rial, 170 Carbon, as a constituent of the food, 124 Carbon compounds absorbed by plants, 125 Carpels, 604 Carpogenous cells, 614 Carpogonium, 614 Carpospores, 614 Cassytha, haustoria of, 411 Caulerpa, 9; geotropism of, 458 Cavendish, on sources of combined nitrogen, 128 Cell ; circulation in, 13,296, 521 ; growth of, 1 6, 334; multinucleated, 27; os- motic properties of, 39; plasmolytic state of (Fig. 3), 13 Cell -fusions, 23 Cell-sap, 13, 28; acidity of, 55 ; colour- ing matters of, 29; composition of, 28 Cellulose, 14, 17; as reserve-material, 170 Cell-wall (Figs. 7, 8), 12, 14; calcium in, 22 ; cuticularisation of, 18 ; growth INDEX. 687 of, 334; formation of, 15, 177; ligni- fication of, 18; mucilaginous degene- ration of, 17 ; in polarised light (Figs. 4, 5), 14, 15; silica in, 21; stratifica- tion of (Fig. 7), 16; striation of (Fig. 8), 16. Theories of growth of; by apposition (Strasburger and Dippel), 16, 336; by intussusception (Naegli), i5> 33°" Centrifugal force; influence of, on direc- tion of growth (Fig. 51), 456; on rate of growth, 410, 413, 461 Ceropegia Gardnerii, circumnutation of, 363. 5'4 Chagtomium, reproduction of, 624 Chaetophora, pulsating vacuole in, 522 Chara, 428 ; rotation of protoplasm in, 521 Characese, 1 1 ; vegetative reproduction of, 599 ; life-history of, 633 Chatin, on aerial roots, 50 Chemical stimuli, action of ; on anthero- zoids, 529; on tentacles of Drosera, 547 ; on zoospores, 529 Chlamydomonas, pulsating vacuole in, 522 Chlorine, as a constituent of the food, 136 Chlorotic plants, 136, 240 Chlorophyll ; absorption-spectrum of, 155; chemical composition of, 154; decomposition of, 266; fluorescence of, 155 ; formation of, 239, 241 ; func- tion of, 151, 156; Lommel's theory, 254; Pringsheim's theory, 157, 261; in Floridese, 152; influence of light on, 262; relation of iron to, 239; spectrum of (Plate i), 155 Chlorophyll-band, movement of, of Me- socarpus, 525 Chlorophyll-bodies, 152 Chlorophyll-corpuscles, 8, 13, 141, 152; movements of, in light (Fig. 36), 299, 526; structure of (Fig. 22), 153 Chlorophyllan, 154 Choanephora, effect of starvation on (Fig. 30), 219 Cholesterin, 243 Chromatin, 27 Chytridiaceae, 605; conjugation of, 618 Chytridium vorax, directive action of light on zoospores of, 524 Cichoritim Intybus, laticiferous vessel of (Fig. 24^), 167 CiesielsM, on geotropism, 464, 467 Cilia, i, 519 Ciliary movement, 519 Circulation of protoplasm, 296, 521, 558 Circumnutation, 362 ; diagram of (Fig. 41), 364; relation to twining, 508 Cistinese, movements of stamens of, 545 Citrus, adventitious budding in, 599 Claviceps, asexuality of, 624; life his- tory of, 634 Cleistogamous flowers, 647 Clinostat (Fig. 48), 417 Cloez, on evolution of oxygen at low temperature, 271 Clostcrium moniliforme, locomotion of, 520; phototaxis of, 525 Cobcea scandens, tendrils of, 486 Ccelebogyne ilicifolia, adventitious bud- ding in, 599 Cohn — on aggregation, 565 on Bacteria exposed to low tempe- rature, 272 on Bacteria exposed to high tempe- rature, 279, 283 on contractile vacuoles, 522, 558 on leaf of Aldrovanda, 587 on effect of exposure to light on leaf of Oxalis, 538 on rotation of protoplasm, 297 on stamens of Cynarese, 568 Cold, effect of, on germination of seeds, 271, 281; on Bacteria, 272 ; relation of, to life of plants, 275 Coleochoete, fruit of, 625; life-history of, 632 Colin, on effects of high temperature on seeds, 280 Collema microphyllum, reproduction of (Fig- 73)> 622 Colophony, 236 Colouring matters, 238; of flowers, 241 Compass-plants, 446, 506 Condensation of aqueous vapour by soil, 48 ; by velamen of Orchids, 50 Confervaceae, 9 Confervoideae, reproduction of, 606 Conidiophore, 602 Coniferin, 234 Conifers, calcium oxalate in, 22 Conjugation, 607 (Figs. 65, 66, 69) Continuity of protoplasm, 23, 374 (Fig. 64), 585 Continuity of reproductive substance, 660 Contractile vacuoles, 522, 558 Contraction, 6, 557 Contractility, 6, 557, 568 Convolvulus, twining of (Fig. 54), 516 Coprinus, etiolation of, 393; heliotrop- ism of, 428 ; hydrotropism of, 478 Corallineae, reproduction of, 615 Cordiceps, asexuality of, 624 Cordyline rubra, geotropism of, 458 688 INDEX. Corenwinder — on absorption of carbon dioxide by growing plants, 82 on absorption of nitrates by roots, 127 Cork, 19 Cornu, on Monoblepharis, 620 Corpusculum, 615 (Fig. 71) Corvisart, on conversion of starch into sugar, 268 Coumarin, 236 Cramer — on starch-grains in chlorophyll- corpuscles, 141 ; on crystalloids in Floridese, 171 Crocus, opening and closing of flowers of, 404; under influence of heat, 378 Cross, on aromatic substances, 233 Cross-fertilisation, 646 Crystalloid, 170, 184 Cunningham, on effect of starvation on Fungi, 218 (Fig. 30) Cupressineae, calcium oxalate in cell- walls of, 22; reproduction of, 616 (Fig. 71) Curcumin, 239 Curve, of daily period of growth (Fig. 45), 401 ; of heliotropic effect of rays of different refrangibility (Fig. 50), 434; of nyctitropic movement of Averrhoa (Fig. 58), 540; of retarding effect of light on growth (Fig. 43), 395 Curvature of organs, mechanism of, in multicellular organs, 579; in uni- cellular organs, 581 Cuscuta, formation of haustoria of, 411 ; positive heliotropism of stem of, 517; sensitiveness of climbing stem of, 491* 5" Cuticle, 17, 1 8 Cuticular transpiration, 107 Cutin, 19 Cutleria, reproduction of, 609 Cuttings, reproduction by, 598, 662 Cyanophycere, reproduction of, 604 Cynareoe, irritable stamens of, 545, 559, 568 Cystocarp, 614 Cystolith, 22; (Fig. 6), 15; (Fig. 34), 249 Cytinu Adami (graft hybrid), 651 Cytoplasm, 658 Cystoseira barbata, extrusion of polar body in, 641 Daily periodic movements of leaves, 539 Daily periodicity, of growth (Fig. 45), 356; 401, 408; of root-pressure, 95, 407; of tension of tissues, 405, 543 Daily variation in bulk, 408 Darkness, effect of, on growth of leaves, 380; of stems, 380, 385 (Fig. 42) Darlingtonia, pitcher of, 247 Darwin, C. — on absorption of carbon com- pounds by leaves, 124 on advantages of cross-fertilisation, 649 on aggregation, 564 on circumnutation, 363 on crosses, 650 on development of adhesive discs of tendrils, 411 on diageotropisin, 463 on diaheliotropism, 449 on graft-hybrids, 651 on heterostyled plants, 648 on insectivorous plants, 547 on localisation of geotropic irrita- bility, 467 on localisation of heliotropic irrita- bility, 438 on localisation of hydrotropic irrita- bility, 479 on nyctitropic movements (Figs. 58, 60), 539 on pangenesis, 653 on paraheliotropism, 551 on sensitiveness of roots to contact, 492 on significance of nyctitropic move- ments, 593 on twining of climbing stems, 508 on twining of tendrils, 484 on transmission of varietal charac- ters, 652 on variation, 675 Darwin, F. — on aggregation, 564 on diaheliotropism of leaves, 448 on geotropism of decapitated roots, 468 on growth in darkness of negatively heliotropic organs, 440 Darwinian curvature, 492 Dasycladus, reproduction of, 608 Davy, on use of silicon in plants, 137 Death, cause of, from high temperatures, 283 Detrain- on absorption of oxygen by roots, 78 on absorption of oxygen by plants, 197 on decomposition of carbon dioxide in artificial light, 258 on evolution of carbon dioxide by plants, 199, 207, 276 on gaseous interchange during ger- mination, 206 Derivative hybrids, 651 INDEX. 689 Desmicls, locomotion of, 520; reproduc- tion of, 6 12 Dcsmodium (Hedysarum) gyrans, leaf of; sleep movements of (Fig. 60), 542, 544; spontaneous movement of, 533. 537 Dessaigne, on luminosity, 319 Destructive metabolism, 188 Detlefsen — on excentric thickening of stems, 353 on localisation of geotropic and hydrotropic irritability, 468, 480 Detmer — on absorption of water by leaves, 66 on destructive metabolism, 292 on evolution of ammonia by germi- nating seeds, 210 exhalation of carbon dioxide by plants in light, 260 on germination at low temperature, 272 on photoepinasty, 383, 444 on root-pressure, 95 Denlzia scabra, cliageotropism of, 472 Development of reproductive cells, 638 Diageotropism, 463, 470, 473, 501, 552 Diaheliotropism, 449, 55 1> 592 Diastase, 189; action of, on starch, 191; analysis of, 189 Diatoms, locomotion of, 520; reproduc- tion of, 613 Dichogamy, 647 Didymium, heliotropism of, 527; in- fluence of temperature on movement of, 298 Differentiation of tissues, 10 Diffusion currents ; effect of, on electrical potential, 322 Dicecism, 646 Dioncea; action of anaesthetics on leaf of, 572; conduction of stimuli in leaf of, 587; distribution of electrical potential on leaf of (Fig. 39), 320; movements of leaf of (Figs. 62, 63), 547 ; plastoid or rhabdoid in cells of leaf of, 565 Dioscorea Batatas, twining of, 517 Dippel— on growth of cell- wall, 16 on movements of Diatoms, 520 on stratification, 17 Dipsacus, absence of heliotropic irrita- bility in, 431 Discs, adhesive of tendrils, 411 Diurnal sleep of leaves, 551 Dodart, on geotropism, 456 Dodel-Port— on extrusion of polar body, 641 on reproduction of Ulothrix, 606 V. Dorsiventrality, induction of, 425 Dorsiventral organisation, 366; organs, 423; directive action of gravity on, 470; directive action of light on, 441 Draper — on chlorophyll-spectrum, 156 on etiolin, 152 on rays of spectrum which decom- pose carbon dioxide, 254 Drechsel, on proteid crystals, 172 Drosera, aggregation in cell of, 564; glands of (Fig. 33), 247 ; localisa- tion of irritability in the gland, 548; movements of tentacles of (Fig. 61), 547; tentacles, 247, 533; transmission if of, Drude — of stimulus in the leaf of, 587 on absorption of oxygen by Neottia, exhalation of carbon dioxide by plants in light, 260 on growth of leaves, 359 Drummond, on luminosity of plants, 317 Dubrunfaut, on inverted cane-sugar, 192 Duchartre — on absorption of water by leaves, 66 on hydrotropism, 477 on positive heliotropism of Clavi- ceps, 428 on root-pressure, 92 on twining in darkness, 517 Ducluzeau, on luminous Algae, 317 Dudresnaya, reproduction of, 615 Duhamel — on absence of geotropic irritability in Mistletoe, 458 on geotropism, 456 Dutrochet — effect of temperature on circulation in Chara, 297 on evolution of heat by plants, 308, 310 on heliotropism, 433 on irritability of stem of Cuscuta, 49 i on loss of heat by plants, 314, 315 on Mimosa not motile in vacuo, 296, 548 motile organs, 296 on movement of leaf of Mimosa, 56o on negative heliotropism of Mistle- toe, 429 on relation between branches and axes, 421 on root-pressure, 90 on rotation of protoplasm, 297 on somatotropism of Mistletoe, 475 44 690 INDEX. Dutrochet — on temperature of plants, 314 on temperature of spadix, 308, 310 on transmission of stimulus in Mimosa, 583, 586 on transpiration-current, 97 on twining of climbing stems, 509, 515 Dworzak, on chlorine in food, 136 Echinocystis lobata, tendrils of, 486, 490 Ectocarpus, conjugation of (Fig. 66), 608 Ectoplasm, 13, 23 Eder, on absorption of water by leaves, 66 Edwards, on effect of high temperature on seeds, 280 Egg-apparatus (Fig. 70), 615 Ehrenberg, on luminous Algae, 317 Electricity in plants, 319; effect on growth, 410 Elfving— on action of gravity at different angles, 460 on formation of etiolin, 264 on galvanotropism, 474 on influence of gravity on rate of growth, 409, 466 on plagiotropism of rhizomes, 501 on transpiration-current, 98 Embryo-sac, germination of, 641 Emmerling — on amides in leaves, 150 on formation of nitrogenous organic substances in plants, 149 Emulsin, analysis of, 189 Enchylema, 25 Endophyllum, life-history of, 634 Endoplasm, 13, 23 Endosmotic current, 40 Endosperm, 170 Endospore, 600 Energy in plants; accumulation of, 289; dependence of, on destructive meta- bolism, 290; dissipation of, 290; evo- lution of, as electricity, 324 ; as growth, 291 ; as heat, 302 ; as movement, 296; expenditure of, 288; supply of in plants with, and without chloro- phyll, 251, 252 Engelmann — on Bacteria as a test for oxygen (Fig. 35). 256 on Bacterium photometricum, 298, 5*3 on contractile vacuoles, 522 on colouring matters of Algae, 256 on decomposition of carbon dioxide by light, 258 Engelmann — on etiolin, 152 on exhalation of oxygen by chloro- phyll-corpuscles, 153 on movements of Diatoms, 520 on movements of Schizomycetes in free oxygen, 255 on theory of chlorophyll-function, 156 Enteromorpha mescntenca, spiral growth of, 512 Entomophthoreos, conjugation of, 617 Epicotyl, curvatures of, 367 Epinasty, 366 Epiphytes, 459 Epiplasm, 638 Erdmann — on glycolignose, 2 1 on lignose, 234 Eremascus albus, reproduction of, 620 Eriksson- evolution of heat by yeast, 306, 307 on temperature of flower seeds, 305 Erlenmeyer — on decomposition of carbon dioxide, 144 on formation of acids, 227 Errera, on glycogen in Fungi, 171 Erythrophyll, 241, 266 Ethereal oils, 236 Ethers, 237 Etiolated leaves, structure of, 384 Etiolated shoots, structure of, 386 Etiolation, 152, 240 Etiolin, 152; formation of, 240, 264 Eugster, on xanthin, 221 Euphorbia splendens, laticiferous cell (Fig. 691 Famintzin — on etiolation, 391 on movements of chlorophyll-cor- puscles, 299 on movements of Oscillatoria, 523 Farlow, on vegetative apogamy in ferns, 60 1 Farsky, on use of chlorine, 137 Fat, formation of, -218 Fatal temperature : for plants, 278; for leaves, 279; for Bacteria. 279 Fatigue, 302, 572 Fatty acids, 225 Female reproductive cell, 608 Ferment-action, 191, 212 ; effect of light on, 268 ; effect of temperature on, 192 Fermentation, 193, 207; acetous, 208; alcoholic, 208; butyric, 209; lactic, 209 Ferments, 188; analysis of, 189; classi- fication of, 189; preparation of, 193 Ferns : apogamy in, 602 ; apospory in, 601 ; life-history of, 629; vegetative reproduction in, 599 Fertilisation, 609; in Phanerogams (Figs. 71, 75, 76), 616 Fibro-vascular tissue, passage of water through, 100 Fiedler, on the effect of high tempera- ture on moist seeds, 281, 282 Filtration under pressure, in Grass- haulms, 10 1 ; in nectaries, 100; in roots, 45, 94 Fisch, on conjugation in Ustilagineas, 618 Fixed light positions, 430, 446, 590 Flaccidity of leaves on shaking, 112 Flemming — on chromatin, 27 on granules in nuclei, 27 Fleury, on absorption of oxygen by seeds, 76 Floridese, n ; reproduction of, 531, 613 Flower, 604 Flower-heads, pendent position of, 342, 455 Flowers, evolution by, of heat, 309; of light, 317 Food of plants, 121 Formic acid, 225, 227 Fragaria, diageotropism of shoots of, 470, 503 ; diaheliotropism of, 44 r Franchimont, on resin, 236 Frank- on calcium oxalate in plants, 231 on diageotropism, 470 on diaheliotropism, 441, 449 on geotropism, 454 on heliotropism, 427 on induction of dorsiventrality, 427 on movements of plants, 299 Frank- on mucilage, 17 Fremy — on chemical composition of chloro- phyll, 154 on cutin, 19 Fries, on luminosity, 317 Fritillaria imperialis, heliotropism of leaf of, 444 Frommann — on continuity of protoplasm, 23 on structure of protoplasm, 24 Frost, effect on leaves, 274; on plants, 273; on seeds, 272 Fucacese, reproduction of, 609 Fucus, analysis of (Godechens), 61 Fiinfstiick, on pendent position of buds, 455 Fungi, life-history of, 633 ; reproduc- tion of, 617 Funkia, adventitious budding in, 599 Gad, on movement of gynostemium of Stylidium adnatum, 536 Galanthus nivalis, pendent position of buds, 455 Gallic acid, 235 Galls, 333 Galvanotropism, 474 Gametangium, 607 Gametes, 607 Gardiner— on aggregation, 565 on continuity of protoplasm (Fig. 64), 585, 23 on water-glands (Fig. 19), 91 Gardner — on formation of chlorophyll, 263 on heliotropism, 433 on luminosity of plants, 318 Garreau — on absorption of oxygen by leaves, 79, 80 on evolution of heat, 305 on loss of weight during germina- tion, 204 on respiration of growing plants, 196 on transpiration, 103, 105, 106 Gartner — on hereditary variability, 676 on hybridisation, 651 on variability of cultured plants, 679 Gases, in plant-tissues, 119 Gaudichaud, on luminosity, 317 Gautier, on chemical composition of chlorophyll, 154, 155 Geddes, on formation of non-nitro- genous organic substance by animals, 159 44—2 692 INDEX. Gemma of Marchantia (Fig. 49), 426 Gemmce of Fern-prothallia ; of Liver- worts; of Mosses; of Sphacelarise, 599 Generative nucleus, 615 Gentiana, absence of heliotropic irrita- bility in, 43 1 Geotropic curvatures, due to heteraux- esis, 465, 467 ; mechanism of, 464, 580 Geotropic irritability, 461 ; localisation of, 467 ; phenomena of, in dorsiven- tral, 469, 552 ; in isobilateral, 469; in radial organs, 455; orthotropic, 455; plagiotropic, 462 Geotropism, 454 (Fig. 51), 593; after- effect, 464; latent period, 435, 464; negative, 458; positive, 458; trans- verse, 463 ; reversal of, 459 Gerland, on oxidation of chlorophyll in light, 266 Germination, 172, 626; changes in re- serve-materials on, 173; evolution of heat in (Fig. 37), 303 ; minimum tem- perature of, 269; optimum tempera- ture of, 277 ; effect of want of oxygen on, 209 Gilbert, on absorption of nitrogen, 85, 126 Glands, 244 (Fig. 32); of carnivorous plants (Fig. 33), 247 Globoid, 170, 184 Glucosides, 234 Glutamin, 221 Glycerin, 229 Glycogen, 171 Glycolignose, 21 Godechens, on ash of Fucus, 61 Godlewski— on absorption of carbon dioxide, 73 on absorption of oxygen during germination, 205 on etiolated seedlings, 390, 392 on evolution of carbon dioxide by plants, 201 on evolution of oxygen, 143 on formation of oil drops in Mu- saceae, 146 on growth of leaves in darkness, 381 on starch-distribution, 163 on starch -grains in chlorophyll-cor- puscles, 142 Goebel, on adventitious budding in Isoetes, 635 Goldfussia anisophylla, movements of style of, 545 Gonium, pulsating vacuole of, 522 Gonoplasm, 619 Goppert— on evolution of heat in germina- tion, 303 Goppert— on germination at low temperature, 272 von Gorup-Besanez — on ash of Trapa, 59 on asparagin in vetch-seeds, 1 74 on diastatic ferments, 189, 193 on peptic ferments, 173 Graham, on osmosis, 40 Grand period, of evolution of heat in spathes, 308; of growth, 354 Granulose, 183 Gratiolet, on evolution of oxygen at low temperature, 271 Gravity; influence of, on direction of growth (Fig. 693 Gutta percha, 237 Gymnosperms ; calcium oxalate in, 22; reproduction of, 615 (Fig. 71), (Fig. 76) Gymnosporangium, 635 Haberlandt, G.— on decomposition of chlorophyll by intense light, 265 on erythrophyll, 267 on minimum temperature of ger- mination, 284 Haberlandt, F. — on effect of high temperature on seeds, 280, 281 on maximum temperature of ger- mination, 277 on minimum temperature of ger- mination, 270, 271, 272 Hcematococcus (Fig. i), i, n; repro- duction of, 605 ; sensitiveness of zoo- spores of, to light, 524 Hales— on absorption of water by leaves, 66 on force of absorption in im- bibition, 37 on loss by transpiration, 104 on physiological significance of transpiration, 115 on root-pressure, 90, 94, 95 on transpiration, 96, 104, 117 Hansgirg, on movements of Diatoms, 520 Hanstein — on distribution of organic sub- stance in plants, 169 on enchylema, 25 on metaplasm, 23 Hartig-— on resin, 232 on tannic acid, 237 on transpiration, 98 Haulms of grasses, geotropic curvatures of, 466 Haustoria, 411 Heat, 268 ; cause of death from, 283 ; conduction of, by wood, 315, 316; evolution of, in fermentation, 307 ; in germination, 303; in opening of flowers (Garreau, Fig. 38), 308; (Kraus), 308; (Dutrochet), 309 fatal temperature for Bacteria, 279; plants, 278; yeast, 279 influence of, on formation of chloro- phyll, 270; on germination, 269; on growth, 402, 577 loss of, by conduction, 313; radi- ation, 313; transpiration, 313 Heckel, on effect of anaesthetics on motile stamens, 549, 551 Hedysarum (Destnodium) gyrans, 533; leaf of (Fig. 57), 535; sleep move- ments of (Fig. 60), 542 Heiden, on absorption of water by leaves, 66 Heidenhain, on distribution of elec- tricity in plants, 320, 322 Heinricli, on evolution of oxygen at low temperature, 271, 276, 277 Heliotropic curvatures, cause of, 439; distribution of, 437 ; latent period of, 435; mechanism of, 440, 579 effect on, of direction of incident rays, 432 ; of intensity of light, 432 ; of rays of different wave length, (Fig. Hofmeister— on reversal of heliotropic properties, 429 on root-pressure, 90, 94, 95 von Kennel- on cutin, 19 on filtration, 99 on effect of high temperature on seeds, 280 on negative pressure in vessels, H5. "7 on transpiration, 100, 107 Holle— on constructive metabolism of Mu- sacese, 146 on evolution of oxygen, 143 Holzner, on decomposition of absorbed sulphates, 149 Homodromous torsion, 514 Homosporous plants, 603 Hook -climbers (Fig. 47), 412 Hop, twining of (Fig. 54), 516 Hoppe, on daily period of heat-evo- lution in Colocasia, 312 Hoppe-Seyler — on alcoholic fermentation, 208 on aromatic substances, 232 on cholesterin, 220 on composition of chlorophyll, 154 on conversion of carbohydrates into fat, 218 on etiolin, 241 on the formation of acids in plants, 227 on globulin, 25 on lecithin, 131 Horizontal position of dorsiventral organs, 470, 503 Hosseus — on ammonia salts in plants, 150 on evolution of ammonia by ger- minating seeds, 210 Hubert, on temperature of spadix of Colocasia, 304 Humidity of air, relation of, to tran- spiration, 1 08 Humus, 48 Hybrids, 648 ; hybridisation, reciprocal, 648 Hydrodictyon utriculatum, reproduction of, 627 Hydrogen, in food of plants, 125; evo- lution of by plants, 209 Hydrotropism, of growing organs, 478, 593; of plasmodia, 528 Hygroplasma, 656 Hygroscopic water, 48 Hypochlorin, 147 Hypocotyl, curvatures of, 367 Hyponasty, 366 Idioplasm, 657 Imbibition, 15, 37 ; heat evolved in, 37 ; influence of acids or alkalies on, 38; of alcohol and salts on, 38; of temperature on, 38 Indican, 239 Indifferent line in cells of Characece, 521 Indigo, 239 Ingenhousz — on absorption of nitrogen by plants, 84 on absorption of oxygen by leaves, 79 on dephlogistication of air, 140 on relation of plants to atmosphere, Intercalary growth in cell-wall of CEdo- gonium, 337 Intercalary zones of growth, 338 Intramolecular oxygen, 203 Intussusception, 16, 336 Invertin, 190 Ipomcea, twining of, 517 Iron, in food of plants, 135 ; in chloro- phyll-molecule, 154; influence of, on formation of chlorophyll, 239 Irritability, 37 1 ; action of anaesthetics on, 549; of fatigue on, 302, 550; of light on, 549 ; of temperature on, 55 1 ; of supply of water on, 554 Irritability ; conditions of, 548 ; localisa- tion of, in root-tip, 468, 474, 479 ; of growing organs, 416 ; of matureorgans, 519; of tendrils, 485; of twining stems, 511; relation between geo- tropic and heliotropic irritabilities, 499 Irritability, specific, 374 Irritable hairs of Dionoea, 548 (Fig. 63) Isobilateral organs, 423 Isoetes, adventitious budding in, 635 ; development of antherozoids of, 639 Isosporous plants, 603, 629 Ivy, dorsiventrality of shoots of, 425 JanczewsM, on callus in sieve-tubes, 166 Jodin, on oxidation of ethereal oil, 267 Johnson — on analysis of plants, 122 on geotropism, 454 on hydrotropism, 477 Juniperus virginiana, fertilisation in (Fig. 695 Just — on maximum temperature for germi- nation, 277 on effect of high temperature on seeds, 280 Kabsch— on effect of anaesthetics on motile leaves, 551 on influence of gases on movement of stamens of Berberis and Helian- themum, 548 on influence of temperature on movement of Desmodium, 537 on motile organs, 296, 298 on movement of gynostemium of Stylidium adnatiim, 536 Karsten, on composition of etiolated seedlings, 390 Kellner— on amides in leaves, 150 on effects of nitrates on exhalation of carbon dioxide by seeds, 202 Kern, on peptone in shoots, 164 Kerner, on irritability of peduncles, 491 Ketones, 236 Kihlmann, on reproduction of Pyronema (Peziza), 621 Kinetic energy, 288 Kirchner — on mucilage, 18 on the effect of decapitation on roots, 468 Kjellmann, on movements of zoospores at low temperatures, 298 Klein, on crystalloids in Mucorini, 171 Knight- on diffusion of organic substances in plants, 169 on effect of movement on growth in thickness, 352 on geotropism (Fig. 51), 456 on hydrotropism, 478 on negative heliotropism of tendrils, 429 on root-pressure, 91 on transpiration-current, 97 Knoblauch, on conductivity of wood, 316 Knop — on absorption of asparagin, etc., by roots, 124 on chlorine, 136 on excretion by roots, 222 Koch, on etiolated shoots, 386 (Fig. 42) Kohl, on mechanism of auxotonic curva- tures, 582 ; on twining stems, 491, 511 Kolbe, on formation of compounds of nitrogen, 128 Kolreuter, on hereditary variability, 676 Konrad, on chemical composition of chlorophyll, 154 Koppen, on relation between temperature and growth, 293, 294, 377 Kossel, on xanthin, 221 Kossmann, on diastatic ferment, 164, 189, 190 Krabbe, on effect of decapitation of roots, 468 Krauch — on peptic ferment in seeds, 173, 190 on diastatic ferment, 189 C. Kraus — on formation of acids in plants, 228 on growth of leaves in darkness, 382, 392 G. Lassar, on luminosity, 315 Latent period, 374, 523; in geotropism, 464; in heliotropism, 435 Lateral roots, 462 ; action of centrifugal force on, 462; action of gravity on, 462 ; proper angle of, 502 Latex, 167; composition of, 168 Lathy rus odoratus, twining of tendrils of, 490 Laticiferous cells and vessels (Fig. 24), 167 Lawes, on absorption of nitrogen by plants, 126 "Laying" of wheat, 137, 386 (Fig. 42) Leaf; absorption by, of gases, 69; of water, 65 fixed light-position of, 445 heliotropism of, 444 structure of (Fig. 13), 69, 384; etiolated, 384 ; peculiarities in, due to fixed light-positions, 591 Lechartier, on alcoholic fermentation in fruits, 209 Lecithin, 131, 225, 243 Lehmann, on relative value of ammonia- salts and nitrates, 127 Lemna trisulca, chlorophyll-corpuscles (Fig. 36), 300 Lenticels (Fig. 14), 71 Leon, on torsion of twining internodes, 515 Leptogium, reproduction of, 623 Leucin, 150, 221 Leucophyll, 262 Leydhecker, on chlorine in food, 136 Lichens, sexual reproduction of (Fig. 73), 623; sorediaof, 599 Liebig— on absorption of carbon dioxide by root, 82 on formation of acids in plants, 227 on potassium in plants, 134 Life, 1 60 Life-history of; Algae, 631 ; Fungi, 633 ; Mosses, 628; Phanerogams, 629; Vascular Cryptogams, isosporous, 629; heterosporous, 629 Light; apostrophe, 299, 527 (Fig. 36) directive influence of, on growth of bilateral organs, dorsi ventral, 441 ; isobilateral, 441 ; leaves, 445; radial organs, 428 epistrophe, 299, 527 (Fig. 36) evolution of, by plants, 316 induction of, fixed position of or- gans, 430; dorsiventrality by, 427 influence of, on absorption of mine- ral food, 258; of oxygen, 260; of carbon dioxide, 82 Light, continued : on action of unorganised ferments, 268; on Bacteria (Engelmann), 255; on constructive metabolism, 151,254; on decomposition of chlorophyll, 263 ; on destructive metabolism, 260 on formation of alkaloids, 268; of chlorophyll, 262 ; of colouringmatters, 262, 267; of etiolin, 264; of non- nitrogenous organic material, 147 influence of, on growth (Fig. 43), 379; stimulating, 299, 400; tonic, 379; phototonus,38o, 573; paratonus, nature of, 573 on locomotion, 523; on movements, 522, 538; on movements of chloro- phyll-corpuscles, 525; on position of zoospores (phototaxis), 525; on respiration, 260; on streaming move- ment of protoplasm, 524; on transpi- ration, 109 Light, inhibitory action of, 398; inhibi- tion of spontaneous movements by, 544; optimum intensity, for growth, 258; for heliotropism, 432; persistent influence of, 396 Light-positions of organs, 430, 446, 590 Light- rays which cause opening of motile leaves, 539; which decom- pose carbon dioxide, 254; which produce heliotropic curvature, 433 ; which retard growth, 397 relation between intensity and de- composition of carbon dioxide, 257; between intensity and heliotropic effect, 432 Lignin, 232; in cell- walls, 18 Lilium bulbiferuni) vegetative reproduc- tion of, 599 Lin aria cymbalaria, heliotropism of, 429 Lindsay, on Mimosa, 560 Litmus, 242 Loasa aurantiaca, reversal of direction of twining in, 517 Localisation of irritability; in growing organs, galvanotropic, 474; geo- tropic, 467; heliotropic, 438; hydro- tropic, 480; in motile organs, 548; in tendrils, 486 Locomotion, 519 Loew — on analysis of ferments, 189 on fat in Fungi, 219 on formation of nitrogenous or- ganic substance in plants, 149 on lecithin, 131 on structure of protoplasmic mole- cule, 1 60 INDEX. 697 Lommel— on physical theory of chlorophyll, 15<5 on rays of spectrum which decom- pose carbon dioxide, 254 Lonicera, twining of, 514, 517 Lophospernmm scandens, irritability of, 49 i Lory, on absorption of oxygen by Oro- banche, 77 Lufobock, on dichogamous flowers, 647 de Luca — on alcoholic fermentation, 209 on evolution of carbon dioxide by plants, 213 on evolution of hydrogen by plants, 209 on mannite in olives, 171 Ludwig, on luminosity, 317 Luminosity of plants, 318 Lunularia, gemmag of, 599 Lynch, on movements of Averrhoa bi- limbi, 536 (Fig. 58) Lysimachia Nummularia, direction of growth of, 441, 442, 450, 469, 503 Ly thrum, heterostylism in, 647 Macrosporangia, 603 Macrospore, 603 Magnesium in food of plants, 135 Mahonia, structure of motile stamens of> 533 Male parthenogenesis, 674 Malic acid, 29; attraction of, on an- therozoids, 529 Malpighi, on germination in absence of oxygen, 292 Maly, on resin, 236 Mandevillea suaveolens, does not twine in darkness, 517 Mannite, 171, 210 Maquenne — on absorption of heat by leaves, 3H on decomposition of carbon dioxide in artificial light, 258 Marcet— on absorption of oxygen by Boletus versicolor, 76 on exhalation of carbon dioxide by Fungi, 197 Marchantia, dorsiventrality of, 425 ; gemmre (Fig. Meyen — on transpiration-current, 117 on luminosity, 317 Meyer— on formation of starch-grains, 181 on relation of iron to formation of chlorophyll-corpuscles, 240 Micella, 32 Micellar theory of Naegeli, 32, 336 Microsomata, 23, 26 Microsporangia, 603 Microspores, 603 Middle Lamella, 19, 20 Miescher, on nuclein, 27 Mikosch— on etiolin, 240 on photochemical induction, 263 Millardet— on movements of Mimosa, 541, 543> 544 on tissue-tensions in Mimosa, 406 Mimosa albida, paraheliotropism of, 552 Mimosa pudica, 23, 302, 312, 324, 533, 538; action of anaesthetics on, 549, 572; conditions of irritability of, 549, 572 ; conduction of stimuli in, 548, 583; daily periodic movements of, 543; fatigue in, 550; mechanism of move- ments, 568; nyctitropic movements, (Figs. 55, 56), 54 1, 57°; ravs favour- able to irritability of, 549; relation between tissue tensions, and nyctitro- pic movements, 543 ; sensitiveness to gravity, 552; to light, 538; to me- chanical stimuli, 544, 561 ; spon- taneous movements of, 537; structure of pulvinus of (Figs. 55, 56), 533 Mimulus, irritability of stigma of, 545 Minimum temperature of growth, 293 Minot, on extrusion of polar body, 672 Mistletoe, 429, 458, 474; absence of geotropic irritability in, 458 ; negative heliotropism of hypocotyl, 429; para- sitism of, 124; somatotropism of, 474 von Mohl — on erythrophyll, 266 on negative refraction of cell-wall, 15 on optical properties of starch- grains, 183 on interference colours in starch- grains, 36 on the relation between geotropic and heliotropic irritability, 498 on resumption of the formation of chlorophyll in spring, 266 on starch-grains in chlorophyll cor- puscles, 141 von Mohl — on transpiration as affected by sto- mata, 107, 108 on twining stems, 491, 508 on twining of tendrils, 490 Moissan — on evolution of carbon dioxide from leaves, 199, 276 on gaseous interchange during ger- mination, 206 Moisture, directive influence on growth, 478 Moldenhawer, on transpiration as af- fected by stomata, 107 Molisch, on hydrotropism, 477 Moil- on absorption of carbon dioxide by leaves, 83 (Figs. 17, 18) on root-pressure, 92 Monoblepharis, reproduction of, 620 Monotropa Hypopitys, ovule of (Fig. 699 529; of electrical stimuli, 524; of external conditions, 522 ; of free oxygen, 296, 522; light, intensity of, 298, 522, 525, 527, 574; direction of, (phototaxis), 524; of temperature, 297, 522, 528; of water of imbibition, 5H Movement; mechanism of, 557; nycti- tropic (Fig. 58), 539, 400; relation of to turgidity, 559; spontaneous, 533; ofplasmodia, 527; of pulsating vacuoles, 522 Movements, streaming, of protoplasm, 296, 521, 558 Mucilage in seeds, 1 7 Mucor, heliotropism of, 428 Mucor mucedo, life history of, 634 Mucor stolonifer, hydrotropism of, 478 Mucorini; conjugation of, 617; life history of, 634 Mulder— on formation of compounds of nitrogen, 129 on geotropism, 454 Mutter- on oxidation of chlorophyll, 266 on resin, 233 on theory of chlorophyll-function, 156 Miiller-Hettlingen, on Galvanotropism, 474 Muller-Thurgau — on growth in darkness of nega- tively heliotropic organs, 440 on heliotropism, 432, 437 on heliotropic curvature, 438 on plants, as affected by low tem- perature, 274 on relation between geotropic and heliotropic irritability, 498 Munk, on electricity, 320, 324 Milntz— on evolution of hydrogen by plants, 209 on ferments, 190 on mannite in Agarics, 1 7 1 on nitrification, 129 Muscinese, 610, 629 Naegeli— on absorption of acids by Fungi, 125, 231, 237 on amount of absorption by cell- walls, 38 on calcium in food of Moulds, 135 on evolution, 657, 680 on fat in Fungi, 219 on formation of starch-grains, 181, 183 on growth of cell- wall, 15 Naegeli— on growth by intussusception, 336 on heat evolved in imbibition, 37 on imbibition, 32 on lecithin, 131 on micellar theory, 33 on movements of Diatoms, 520 on nitrogenous food of Fungi, 128 on organic substances as food of Fungi, 125 on plasmolysis, 44 on potassium in food of Fungi, 134 on relation of growth to destructive metabolism in yeast, 292 on starch-grains in chlorophyll-cor- puscles, 141 on strontium in food of Fungi, '35 on stratification, 17 on reproduction, 656 Narcissus pseudo-narcissus, diageotro- pism of flower heads of, 463 Nectar, 246 Nectary, 101, 246 Negative pressure, of gases in vessels, 118 Nepenthes, glands of, 247 Nephrodium, bulbils of, 599 Nephrolepis, adventitious budding of, 599 Nervimotility (Dutrochet), 475 Nicotiana tabacum, geotropic curvatures of, 466 Niepce de St Victor, on conversion of starch into sugar, 268 Nitella, heliotropism of, 428 Nitrates, 127, 150 Nitrification, 129 Nitrogen, absorption of, 85, 126 (Fig. 20), combined; sources of, 128; com- pounds absorbed by plants, 127; losses of, 129 Nitrogenous metabolism in plants ; con- structive, 150; destructive, 220 Nitrogenous organic substance, distri- bution of, 165; formation of, 148 Nobbe— on chloride of potassium, 132; chlorine, 136 on distribution of roots in soil, 52 on roots in salt-solutions, 51 on water-culture, 134 Non-nitrogenous organic substance, for- mation of, 140; conditions favour- able to, 147; distribution of, 164; plastic, 216; waste, 255 Nostoc, formation of spores in, 602 Nothoscordum fragrans, adventitious budding in, 599 7<DO INDEX. Nuclear fusion, in sexual process, 643 ; between somatic cells, 672 Nuclei'n, 27 Nucleo-idioplasm, 658 Nucleolus, 13, 26 Nucleus, 13, 26; composition of, 27; reticulate structure of, 27 ; vegetative, and generative, 615, 640 Nutation, 360 ; mechanism of, 582 ; re- volving, 361 (Fig. 41); simple, 361; undulating, 368 Nutrition, 289 Nyctitropic movements (Figs. 58, 59, 6o)> 405. 539 Oat-plants, analysis of (Arendt), 63, 129; (Herapath), 63 Oedogonium, growth of cell- wall of, n ; reproduction of (Fig. 67), 610 Oogonium, 609 Oomycetes, reproduction of, 618 Oophore, 628 Oosphere, 609 Oospore, 609 Opening of flowers, 378, 400, 403 Optical properties of organised bodies, 33; of cell-walls, 14 (Figs. 4, 5); of chlorophyll (Plate i), 155; of cuticu- larised cell- walls, 36; of cystoliths, 15 ; of starch-grains, 35, 182 (Fig. 27) Optimum light-intensity; for growth, 258 ; for heliotropic curvature, 499 Optimum temperatures, for alcoholic fermentation, 277 ; ferment- action, 277; germination, 277; growth, 293 Opuntia, metabolism of, 197, 207, 231 Orchids, air roots of (Fig. 12), 51 Organic acids in plants, classification of, 225; formation of, 227; relation of, to turgidity, 41, 232, 391, 563, 580 ; significance of, 230 Organic substance, distribution of, 162; formation of, 140, 158 Organized bodies, imbibition of, 31; molecular structure of, 31 ; optical properties of, 33 Organs, definition of, 9 Organs, anisotropic, 424; bilateral, 422; dorsiventral, 423 ; isobilateral, 423 ; orthotropic, 424; plagiotropic, 424; radial, 422 Organs, growing; structure and pro- perties of, 338; irritability of, 375; tensions in, 342 Organs, motile, 372 ; irritability of, 519; structure of (pulvinus), 533, (Figs- 55> 56) Organs, specific irritability of, 374, 497, 500 Origin of species, 680 Orthotropic organs, 424 Oscillatoria, locomotion of, 520 Osmometer, 40 Osmosis (Fig. 9), 40, 89 Osmotic properties of cell, 39 Osmotically active substances, 41 Oudemans, on absorption of oxygen by seeds, 76, 77; on evolution of am- monia by germinating seeds, 210 Ovule (Fig. 70), 603 Oxalic acid, 124, 227 Oxalis acetosella, pulvinus, 533; in- fluence of light on leaves of, 538; effect of variation of temperature on, 544 ; spontaneous movement, 537 Oxalis, heterostylism of, 647 Oxalis sensitiva, irritability of, 545 Oxygen, in food, 126 absorption of, by plants (Figs. 