812 



INDEX 



Water-sprout, 250 



Water-vapor gradient, 228 



Wax, 169 



Weeds, 2, 41, 45, 46, 717 



Whales and plankton, 604, 605 



Wheat, 425; embryo, 295; flower, 357; 

 grass, 766; rust, 559, 560; seedlings, 

 190; smut, 558; spring, 435; winter, 

 435 



Willow, 102; family, 702 



Wilting, 231; percentage, 320 



Wilts, 574 



Winter, aspect, 34; conditioning, 35; 

 fat grass. 769; injury, 35; view in 

 forest, 34; wheat, 435 



Wolffia, 15, 85 



Wood, 262; block. 290; cylinder, 262; 

 diffuse-porous, 288; fibers. 284, 285; 

 grain, 264, 289; non-porous, 289; ring- 

 porous. 288; rots, 579, 580; sections, 

 285, 288, 289, 291; spring. 287; sum- 

 mer, 287 



Wound, 292; surfaces. 477; tissue, 292, 

 418 



Xanthophyceae, 608, 627 



Xanthophylls, 28, 608 



Xenia, 381, 470 



Xeniophyte, 379 



X-rays, 398, 485 



Xylem, 71, 72, 223, 262, 266, 284, 303; 



parenchyma, 284; primary, 304; ray, 



284; secondary, 304 



Yam, 714 



Yeasts, 155. 546, 547 



Yucca, 700 



Zein. 142 

 Zinc, 330 

 Zoology, 7 

 Zoospore. 617 



Zygote, 376, 545, 547, 548, 636; to 

 embrvo. 387 



