470 VEGETABLE 
84; exudation of, under pressure, 
88; exudation affected by salts, 
Ol 
Water-culture, 132, 177 
Water-glands, 344 
Wax in cell-walls, 55 
WIisnzrR on composition of cell- 
wall, 49; on heliotropism, 407 
WustAtter on chlorophyll, 149 
Withering, 96 
Wood, 26 
Xanthophyll, 149, 277 
Xerophytes, 343 
PHYSIOLOGY 
Yeast, 2, 307, 421, 429 
Zein, 169 
Zine, 135, 181 
Zirconium, 181 
Zooceenocyte, 430 
Zoogonidia, 1, 428 
Zoophilous flowers, 449 
Zoospores, 1, 428 
Zygnema, 150, 431 
Zygospore, 431, 434 
Zy gote, 434 
Zymase, 260, 307 
Zymogen, 251 
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