7o8 



INDEX 



Vascular Cryptogams, 231 ~ 

 Vascular gaps, 465 

 Vascular plants, 122, 165, 222 

 Vaucheria, 562, 564 

 Veins, 



development, 333 



pseudo-, 381 



structure, 334 

 Velum, 537, 558, 604 

 Venation, 



cotyledon, 326 



Ferns, 580 



Pecopteris type, 580 



Sphenopteris type, 580 

 Ventral hairs, 



Metzgeria, 86 

 Ventral lamellae, 



Marchantiaceae, 43 



Ricciocarpus, 40 

 Viscum, 504 

 Vittaria, 233, 393, 394 



Walking fern, 310 (see also Camp- 



tosorus) 

 Water-absorption, 565, 566 

 Water-conducting cells, 222 

 Water-conduction, 565 

 Water-conservation, 



Marchantiaceae, 69 

 Water supply, 229, 568 

 Webera nutans, 160 

 Weisia, 218 

 Wiesnerella, 612, 614 

 Woodwardia radicans; Figs. 183', 

 184 



Xerophytes, 230 



Xerophytic Marchantiaceae, 67 



Yucca, 554, 590 



Zamia, 321 



Zoospores, 9, 86, 563, 593 



Zygote, 563, 566, 569 



Printed in the United States of America. 



