6 9 6 



INDEX. 



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 



