696 



SUBJECT INDEX 



Xylem parenchyma, 222, 226-228, 



561 

 Xylem rays, 221, 222, 223, 225, 228 

 Xylose, 371-372 



Zeaxanthin, 315 



Zinc, role of, 425 



Zymase, 531-532, 536, 537, 541, 542 



Zymogens, 462-463, 627 



