INDEX 



459 



Water ascent, 144-146 



Water ascent, path of, 141* 



Water ascent, rate of, 145 



Water ducts, 93* 



Wheat, rust of, 274, 275* 



White oak, 383*~386 



White oak, inflorescence and flowers 



of, 385* 



White oak timber, 384* 

 White sweet clover, seasonal life of, 



130, 131* 

 Willow, 387, 388* 

 Willow, reproduction of, 388* 

 Wing petals, 168, 169* 

 Wood, destruction by fungi, 273* 

 Wood, diffuse-porous, 382* 

 Wood, ring-porous, 381* 

 Wood, sections of, 87*, 88*, 89* 

 Wood, spring and summer, 85*, 86 

 Wood of alder, 91*, 92*, 93* 

 Wood of lilac, 85* 

 Wood of maple, 88* 

 Wood of oak, 86*, 101* 

 Wood of red oak, 89* 

 Wood cylinder, 84 

 Wood fibers, 93*, 94 

 Wood parenchyma, 92*, 93*, 94 

 Wood rays, 87*, 94 



Xerophytes, 148* 



Xerophytes, leaf structures of, 149* 

 Xerophytic association, 435, 438* 

 Xylem, 92*, 93* 

 Xylem elements, 96*, 97, 98 



Yarrow, inflorescence and flowers of, 



411*, 412* 



Yeast, spore formation in, 247 

 Yeast cells, 245* 

 Yeasts, 234-250 

 Yeasts, budding of, 245*, 246* 

 Yeasts, top and bottom, 244* 

 Yeasts, wild and cultivated, 244* 

 Yeasts, wine and beer, 244* 



Zamia, 321-325 



Zamia, life history of, 324* 



Zamia, strobilus, sporangia, and game- 



tophytes, 323 



Zea mays, root system of, 112*, 193* 

 Zea mays, stem structure of, 109* 

 Zonation, 441*, 442*, 444 

 Zoosporangium of VaucJieria, 233* 

 Zoospore of CEdogonium, 235* 

 Zoospore of Vaucheria, 232, 233* 

 Zoospores of Chlamydomonas, 222 

 Zoospores of OEdogonium, 235 

 Zoospores of Vaucheria, 233 

 Zygote, 57, 159, 160* 

 Zymase, 246 



