5 8o 



BOTANY OF THE LIVING PLANT 



Woodwardia, sporophytic budding in, 



336 (Fig. 277). 

 Wrought-iron, qualities of, 146. 



Xanthoria, 438 (Fig. 372). 

 Xerophytes, plants adapted for life 



under conditions of drought, 96, 



175 ; thorny character of, 176 ; 



succulence of, 176 (Fig. 132) ; 



glandular hairs of, 177 ; sunken- 



stomata of, 177 (Fig. 133). 

 Xylem, the woody region of the 



vascular strand, 37 (Fig. 23), 39 



(Fig. 24). 



Yellow-flag (Iris), 496 (Fig. 400). 

 Yellow-rattle (Rhinanthus), green 



root-parasite, 189, 193. 

 Yew (Taxus), 302. 



Zea (Maize), vascular bundles of, 44 

 (Figs. ,30, 31) ; analysis of grain, 

 547 ; origin of, 548. 



Zizyphus, straggling by stipules, 181 



(Fig. 134, ii.). 

 Zoogloea, of Bacillus subtilis, 458 



(Fig. 39i). 

 Zoosporangium, of Pythium, 415 



(Fig. 35i). 

 Zoospore, a spore motile in water : 



of Ulothrix, 392 ; of Oedogonium 



(Fig. 331) ; of Bulbochaete (Fig. 



332) ; of Vaucheria (Fig. 334) ; 



of Pythium, 415 (Fig. 351) ; of 



Potato-Fungus, 418 (Fig. 355) ; 



infection of Potato by, 419 (Fig. 



356). 



Zygnemaceae, 398. 

 Zygomorphic, lop-sided symmetry 



within the flower, 240 (Figs. 183, 



189). 



Zygomycetes, 410, 412, 423. 

 Zygosporeae, 454. 

 Zygospores, 410 (Fig. 345) ; of Mucor, 



426. 

 Zygote, the product of fusion of two 



gametes (syngamy) : of seed-plants, 



271 (Fig. 215), 274 ; of Ferns, 345 ; 



of Oedogonium, ^594. 



GLASGOW: PRINTED AT THE UNIVERSITY PRESS BY ROBERT MACLEHOSE AND co. LTD. 



