670 



INDEX 



Winter eggs, 491 

 Witch-hazel, 505 

 Wolf, 477 

 Wood, Dr., 611 

 Woodruff, 417 

 Worker bee 



lateral view, 202 



mouth parts, 205 

 Worms, 499, 531 



round, 219 



spiny-headed, 219 



tape, 219 

 Wrist, 544 



Xanthophyll, 258 

 X-chromosome, 468 

 Xerophytes, 6 

 Xiphidium, 467 

 Xylem, 243, 245, 2^8, 250 



Y-chromosome, 468, 469 

 Yeast, 71 

 Yellow fever, 619 

 Yellow spot, 360 

 Yerkes, R. M., 387, 538 

 Yolk sac, 423, 4^4, 488, 501 

 Yolk stalk, 426 



Zebra, 508 



Zonal distribution, 4^ 

 Zoochlorellae, 180 

 Zoology, systematic, 64 

 Zoospores, 47 



Ulothrix, 171 

 Zucker, 279 

 Zygnion, 563 



Zygospores, Spirogyra, 170 

 Zygotes, 417 



Closterium, 164-165 



Spirogyra, 171 



