512 INDEX. 



Vocal sac, 9, 51 ; ligament, 21 

 Vorticella, 359, 368 



WOOD, 446, 454, 463. 47 2 

 Wood-cells, 473 



X. 



XlPHISTERNUM, 69 

 Xylem, Bean, 463, 464, 

 Fern, 446, 448, 449, 454 

 Xylem-parenchyma, 455 



473 



Y. 



YEAST, 377388 



Yellow-brown tissue, 242, 243, 267 



ZONITES, 241, 248 



Zoogloea, 409, 412 

 Zoospores, 391, 393 

 Zygapophyses, 56 

 Zygospore, Mucor, 423 ; Spiro- 

 gyra, 4 or, 407 



CAMBRIDGE: PRINTED BY c. j. CLAY, M.A. AND SONS, AT THE UNIVERSITY PRESS. 



