640 INDEX 
Woodwardia orientalis, 351, 352 Yeast what is, 98 
Yucca. 62 
X 
z 
X -chromosome, 359, 360 
Xeno-parasitism, 343 Zamia, 333, 393, 4-11, 610 
Xylem, 65 floridana, 404, 407 
y Zea Mays, 62, 8s, 123, 299, 562, 563 
Zygospores, 345 
Yeast, 95, 98, 306 Zygote, 180 
