604 



INDEX 



Windburn, 48. 97, 259. 



Wing, 358 ; on fruits, 350, 351. 



Winter-killing, 259. 



Witches' brooms, 198, 199, 458, 469, 



543. 



Wolffia, 534. 

 Wood, 130 ; fibers, 265 ; grain, 124 ; 



parenchyma, 130. 

 Wooden Flower, 200. 



Xanthophyll, 89, 90, 91; composi- 

 tion, 108. 

 Xenia, 353. 

 Xerophyte, 190, 569. 

 Xylem, 122, 130, 222, 262. 



Yam, 537. 



Yeast, 169, 458, 459. 



Yellow fever, 407. 



Yew, 523. 



Yucca, 570 ; pollination, 293. 



Zamia, 519. 

 Zingiberacece, 538. 

 Zooglcea, 403, 404. 

 Zoospores, 301, 357, 397. 

 Zygnemacece, 425. 

 Zygomycetes, 437. 

 Zygophycece, 424. 

 Zygospores, 397. 

 Zygote, 397. 

 Zymase, 110. 



Printed in the United States of America. 



