SUBJECT INDEX 



903 



Tissue cultures, 843 



diurnal periodicity in, 521 

 Tomato 



gibberellic acid, effect on growth, 

 171, 172 



light, effect on growth, 171 

 Transformation, 418, 420 



induction of flowering, 419 



as model of induction, 41 1 

 Transients, 481, 483, 485, 487, 488, 



490-493, 495 

 Turgor pressure 



diurnal periodicity of, 507 

 Twilight 



light intensity at, 617 



Ultraviolet 



action of, 43-45 

 Ulva 



derivative spectrum of, 33 

 Urethane 



influence on diurnal periodicity, 

 519, 520 



Vegetative apex 



change to flowering apex, 262- 

 272 

 discussion of, 269-271 

 histological changes, 268-270 

 pattern of zonation, 257 

 Vegetative growth 



interaction of blue radiant energy 



andFMN, 214 

 photoreaction, red, far-red, 129- 

 134,207-214 

 bean hook assay for, 207, 213 

 beans, 133, 134 

 effect on histology of bean 

 hook, 207 



interaction with cobalt, 211, 



214 

 interaction with FMN, 211- 



214 

 interaction with gibberellin, 



208, 210 

 interaction with lAA, 211-214 

 interaction with kinetin, 210, 



211,213 

 millet, 131, 132 

 pine, 129, 130 

 soybean, 130 

 tomato, 130 

 Vernalization, 420 

 Virus 



as model of induction, 417 

 Vision 



limits of, 452, 453 

 cone, 452, 453 

 rod, 452, 453 

 Visual purple, 4 

 Vohinism, 588 



Wavelength; see also Spectra; Spec- 

 trum 

 morphogenetic effects in lettuce, 

 119-125 



Weber-Fechner law, 461, 462 



Woody plants 



dormancy in, 225-247 

 effect of gibberellic acid, 231, 232 

 effect of leaves on, 226-229 

 photoperiodic effects, 225-247 

 rooting of cuttings of, 229-234 



Xanthinin, 308 

 Xanthium 



flowering under long days, 311 



