INDEX 
tive, 127, 127*, 128*; reproduc- 
tive, 133; secretory, 133, 133*; 
storage, 132; strengthening, 129, 
129*, 130*. 
Toadstools, 382; described, 384; de- 
structive, 388. 
Tobacco, flower, 13, 12*; leaf arrange- 
ment, 239* 
Tomato, described, 491; ovary, 36, 
34*, 36*; pistil natural size, 37, 
37*. 
Torus, 12. 
Toxins, 1238. 
Tracheae, 131. 
Tracheids, 130, 131*. 
Trailing Arbutus, 490. 
Transpiration, 241; advantages, 263; 
amount, 262; conditions affect- 
ing, 263; dangers, 265; described, 
260-269; protection against, 266. 
Traumatropsim, 152. 
Tree Ferns, 427, 428*. 
Trichogyne, 327. 
True Ferns, 426. 
Truffles, 366. 
Tryptophane, 281. 
Tube nucleus, 42, 42*. 
Tuber, 179, 179*; described, 181. 
Tuberales, 366. 
Tubular Algae, 316-318. 
Tubular flowers, 25, 24*. 
Turgor pressure, 119. 
Twiners, 176. 
Typhaceae, 495. 
Tyrosin, 281. 
Ulothrix, 311, 311*. 
Umbelliferae, 488. 
Umbel, 30, 30*, 32*. 
Uredinales, 396. 
Uredospore, 399. 
Urticaceae, 478. 
Vacuoles, 114, 114*, 115*, 156*. 
Variation, 517, 518*, 519*. 
585 
Variation, causes, 531; continuous, 
525, 526*; discontinuous, 527. 
Vascular bundles, 130, 130*. 
Vascular cylinder, 145, 146, 146*. 
Vaucheria, 317, 316*. 
Vegetative reproduction, 409, 422. 
Vein, 244, 244*, 
Veinlets, 245, 244* 
Velamen, 163. 
Venation, 245; netted, 245, 244*; 
parallel, 245, 244* 
Venter, 409, 410*. 
Venus Flytrap, 273, 273* 
Vernal habit, 170. 
Volva, 386, 384*. 
Volvocales, 307. 
Volvox, 305, 306*. 
Walnut family, 474. 
Warmth, as an ecological factor, 501. 
Water, as an ecological factor, 50). 
Water Ferns, 426. 
Water Mold, 353. 
White Heart Rot, 389. 
White Rust, 359. 
Willow family, 473. 
Wilt Disease, 378. 
Wind, as an ecological factor, 502. 
Wing, of corolla, 24, 23* 
Witches’ Brooms, 377, 
Wood fiber, 129, 130, 130*. 
Xanthophyll, 284. 
Xenia, 51, 51*. 
Xerophytic societies, 509; kinds, 510. 
Xylem, 130, 130*; of roots, 146, 149, 
146*, 149*; of stems, 188, 190* 
Yeasts, 377. 
Zoéglea stage of Bacteria, 342, 343*. 
Zoéspores, 302. 
Zygospore, 302. 
Zygote, 302. 
Zymase, 94, 285. 
