INDEX 
Wood-rays, 170 
Wood-wedge, 170 
Wormwood, 615 
Xanthophyll, 99, 100 
Xanthorhiza, 519 
Xanthoxyli Fructus, 546 
Xanthoxylum, 546 
Xerophytes, 164, 617, 619 
Xylem, 140 
defined, 142 
primary, 143 
ray, 139 
secondary, 143 
stages in development of elements 
of, 138 
Yam Family, 491 
Yarrow, 615 
Yaupon, 25 
Yeast, Brewer’s, 382 
Compressed, 386 
vitamins in, 105, 106, 386 
Wine, 386 
Yeasts, bottom, 383, 386 
classification of, 382 
defined, 381 
top, 384, 386 
Yellow Jasmine, 583 
Yellow Parilla, 521 
Yerba Santa, 592 
Yew, 467 
Fig. of tracheid of, 23 
Yew Family, 465, 466 
Yohimbe, 605 
Yucca, 220, 259 
793 
Kamia, 455 
life history of, 456 
outline of life cycle, 462 
Kamia floridana, Fig. of, 459 
Kanthorhiza apiifolia, 519 
Kanthoxylea, 545 
Kanthoxylum, 545 
Americanum, 546 
XKanthoxylum Clava Herculis, 546 
Zea N. F., 485 
Kea Mays, 485 
' Fig. of, 483 
starch of, 79, 80 
structure of stem of, 215, 216 
Zedoaria, 492 
Zingiber, 492 
Aingiber officinale, 492 
Fig. of, 493 
Aingiberacea, 492 
Zizyphus, 556 
Aizpphus sativa, 556 
Zéogloea, 178 
Zoology, defined, 1 
Zoéspore, 45, 342, 345, 353 
Figen. Of, 305 
Zoéspore formation, 45 
Xostera, 291 
Zygnema, 343 
Fig. of, 338 
Kygnemacea, 343 
Zygomycetales, 376, 377 
Zygophycez, 333 
Zygophyllacez, 544 
Zygospore, 46, 342, 345, 353 ,379 
Zygote, 16, 46, 345, 348, 380, 461 
Zymase, 102, 103 
Zymogens, 364 
