384 



INDEX 



True ferns, 327 



molds, 290 



mosses, 320 

 Truffles, 294 

 Trunk, 88 

 Trypsin, 124 

 Tryptophane, 122 

 Tube-nucleus, 196, 347 

 Tuber, 93, 94, 184 

 Tuberales, 294 

 Tubiflorales, 364 

 Tubular algae, 272 

 Tulip-tree, twig of, 96, 97, 9 

 "Tumble weeds," 201 

 Turgidity, of plant cells, 55 



Ulothrix, 270, 271 

 Umbel, 193, 363 

 Umbellales, 363 

 Unisexual flower, 192 

 Unit characters, 212 

 Uredinales, 297 

 Uredospore, 297, 298 

 Ustilaginales, 297 



Vaccination, 288 

 Vaccinium, flower of, 190 

 Vacuole, of cell, 45, 141 

 Valves, of diatoms, 276 

 Variation, 208, 209 



in floral parts, 188 



produced by environment, 210 

 Vascular plants, 326 

 Vaucheria, 273 

 Vegetative reproduction, 182 



structures and functions, 182 

 Veins, of leaf, 63, 65, 66, 68 

 Venation of leaf, 63, 65 

 Venter of archegonium, 312 

 Ventral canal-cell, 312 

 Venus 's Fly Trap, 173 

 Vessel, 101, 356 



Vessel-cell, 100, 101 



Vestigial organs, 231 



Volva, 299 



Volvox, 269 



de Vries, theory of, 238 



W 



Water, absorption of, 53, 54 



capillary, 25 



rise of, in soil, 27, 28 



gravitational, 25 



hydrostatic, 25 



hygroscopic, 29 



importance of, 24, 74, 163 



in soil, 24 



movement of, in soil, 26 



percolating, 25 

 Water columns, cohesive power of, 



112 

 Water ferns, 333 

 Water films, 26 

 Water-holding capacity, 26 

 Water-lily, 166 

 Water-milfoil, 166 

 Water molds, 291 

 Water table, 25 



Water-requirement of plants, 76 

 Wave-lengths, of light, 71 



used in photosynthesis, 72 

 Wheat, rust of, 298 



starch grains of, 120 

 Whorl, 91 

 Wild carrot, 363 

 Willow, flowers of, 192 

 Wind-pollination, 193, 194 

 Wood, 100, 105-111 



differences in, 108 



oak, 110 



of root, 47 



of stem, 100 



pine, 108, 109 



three planes of section of, 106 

 Wood-fiber, 100, 101 

 Wood-parenchyma, 100, 101 

 Wood-ray, 100, 101, 107 



