232 



INDEX 



XANTHIUM echinatum, Figs. 134, 



135, pp. 212, 213 

 Xanthoxylum americanum, Fig. 



102, p. 167 



YAMS, wild, Fig. 98, p. 163 

 Yarrow, Fig. 107, p. 174 

 Yeast, 41, 52 

 Fig. 13, p. 42 

 habitat, 41 

 histology, 41 

 physiology, 43 

 reproduction, 44 

 Yellow lily, wild, 109 



development of female game- 

 tophyte from macrospore, 

 114 



Yellow lily, wild, development of 

 male gametophyte, 116 



fertilization, 117 



Figs. 64-69,99, 132, pp. 110- 

 115, 164, 205 



habitat, 109 



morphology, 109 



pollination, 116 



structure of flower, 109 

 of pistil, 111 

 of pollen grains, 116 

 of stamen, 116 



Z 



ZEA mays, Fig. 122, p. 193 

 Zingiber zingiber, Fig. 75, p. 134 

 Zygospore, 30, 49 

 Zygote, 30 



