470 



VEGETABLE PHYSIOLOGY 



84 ; exudation of, under pressure, 

 88; exudation affected by salts, 

 91 



Water-culture, 132, 177 



Water-glands, 344 



Wax in cell- walls, 55 



WIESNEB on composition of cell- 

 wall, 49 ; on heliotropism, 407 



WILSTATTER on chlorophyll, 149 



Withering, 96 



Wood, 26 



Xanthophyll, 149, 277 

 Xerophytes, 343 



Yeast, 2, 307, 421, 429 



Zein, 169 

 Zinc, 135, 181 

 Zirconium, 181 

 Zoocoenocyte, 430 

 Zoogonidia, 1, 428 

 Zoophilous flowers, 449 

 Zoospores, 1, 428 

 Zygnema, 150, 431 

 Zygospore, 431, 434 

 Zygote, 434 

 Zymase, 260, 307 

 Zymogen, 251 



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