SUBJECT INDEX 



523 



Vitality, under Seeds, and Pollen 

 Vivipary, 431, 460 



Water, absorption of, by epiphytes, 

 71 ; by hairs, 74, 76 ; by 

 roots, 47 ; forces concerned 

 in, 49 sqq. ; excretion of, 201 

 sqq., 230 

 content of leaves, 161 ; move- 

 ment in soil, 61 ; storage in 

 leaves, 161 ; storage in stems, 

 161 ; storage by trees, 163 ; 

 storage tissues, 161 ; supply 

 of, to parasites, 220, 221, 

 225, 236 ; supply of, by soil, 

 54 ; supply of, and myco- 

 rhiza, 246, 249 ; supply of, 

 and soil constitution, 56 

 necessity of, for plant, i 

 available, 54 ; balance, 160, 

 173 ; free, i4> 62 ; growth, 

 54 ; physiological, 54 ; un- 

 free, 14, 62 

 Water vapour, diffusion of, through 

 stomata, 99 



Weeds, 448 

 Wilting, 160 



of succulents, 197 

 determination of, 54 

 permanent, 54 ; incipient, 174 

 and assimilation, 141 ; and leaf 

 water-content, 160 ; and sto- 

 ma tal closure, 107 ; and 

 stomatal opening, 173 

 Winter green flora, 449 

 Wood , and water conduction ,188,190 

 Woody tissues, 285 



asymmetrical development of, 

 291 



Xenogamy, 35s 

 Xerophyte, 190, 199 



adult forms of, 446 ; hairiness 

 of, 184 



moorland, 190 

 Xerophytism, factors causing, 200 ; 



significance of, 299 



Youth and adult leaves, 154, 184 

 445 SQQ- 



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