SUBJECT INDEX 



459 



Trichloroethylene: effects on dormant potato tu- 

 bers, 233-234 

 2,4,5-Trichlorophenoxyacetic acid, 209, 218 

 2,4,6-Trichlorophenoxyacetic acid, 218 

 a-(2,4,5-Trichloropiienoxy)-n-butyric acid, 209, 218 

 /3-(2,4,6-Trichlorophenoxy)-/3'-chlorodiethyl ether, 



218 

 a-(2,4,.5-Trichlorophenoxy)-propionic acid, 209, 218 

 Trifolium, 29, 30, 35, 36, 38 

 2,3,.5-Triiodobenzoic acid, 223 

 Trillium erectum: dormancy and germination of 



seeds, 120-121 

 Trillium grandiflorum: dormancy and germination 



of seeds, 119-121 

 2,4,5-Trimetli.\lpbenoxyacetic acid, 218 

 Tropisms: efTects of growth substances, 225-226 

 Tuber, mother-: chemical analyses of mother-tuber 



seed-pieces during development, 421-423 

 importance of mother-tuber in growth of potato 



plant, 420-423 

 method of removing mother-tuber from plant at 



any stage of development, 421 

 Tubers: dormancy in, 230-256 

 Twin-leaf method of studying changes in leaves, 



408-414 

 Typha, 91 



Ultraviolet: antirachitic action, 285 



induction of antirachitic effect in plants, 321 

 Ultraviolet effects: irradiated cinnamic acid pro- 

 duces epinasty in plants, 220 

 on ash of plants, 322 

 on mineral composition of plants, 322 

 on phenyl compounds, 323 

 on plants, 2So, 320-323 

 on tobacco mosaic virus, 323 

 on vitamin D, 321-322 

 red pigment production in apples, 320-321 

 (See also Quality of radiation effects) 

 Ultroil: effects on efficiency of insecticides, 357 

 Urea-Ammonia Liquor-37: comparison with other 

 insoluble nitrogen compounds as fertilizer, 

 42(1-427 

 Uromyces caryophyllinus : effects of pentathionic 

 acid, sulphuric acid and hydrogen sulphide 

 on germination of spores, 363, 366 



imUisne'iia spiralis: 15, 20, 22, 26 



sea-water tolerance, 20 

 Valonia: formation of the cellulose particles, 273- 



282 

 Valonia macrophysa, 273 

 Valonia ventricosa, 273 



Vegetables: carbon dioxide storage efTects, 399 

 Venturia inaequalis: effects of sulphuric acid and 



hydrogen sulphide on germination of spores, 



363-366 

 Verbascum, 35, 36, 37, 38, 40, 41, 42, 76 



Verbena, 35 



Verbena phlogiflnra: carbon dioxide effects on flower 



color, 403 

 Veronica, 42 

 Viburnum: 414, 419 



dormancy, germination. 113 



seedling production, 113, 117-118 

 Viburnum acerifolium, 113, 116, 117 

 Viburnum dentatum: 113 



chemical changes in leaves during period pre- 

 ceding frost, 412—414 

 Viburnum dil at at um, 113, 116, 117 

 Viburnum nudum, 118 

 Viburnum opulus, 113 

 Viburnum prunifolium, 113, 116, 117 

 Viburnum scabrellum, 118 

 Viburnum tomentosum, 245 

 Vicia, 40, 51, 73 



Virus diseases: statistical method for estimating 

 virus infectivity, 439 



(See also Aster yellows; Peach yellows) 

 Viruses: studies on yellows, 10-15 

 Viscum, 75, 78 

 Viscum album: dormancy and germination in seeds, 



123 

 Vitality of seeds: carbon dioxide effects, 33 



impermeable coat effects, 51 



Nelumbo nucifera, 50-51 



seed coat efTects, 52 



under controlled storage conditions, 52-60 



(See also Seeds: vitality) 

 Vitality tests: chemical methods, 131 



embryo methods, 129-131 

 Vitamin Bi: as growth substances, 419—420 

 Vitamin D: ultraviolet effects, 321-322 

 Vitis, 91 



Watsonia, 30 

 Wheat: yarovization, 334 

 Wild rice: (See Zizania arjjiaticn) 

 Willow: effects of illuminating gas on roots, 173 



Xanthium, 46, 82, 84, 85 



X-ray diffraction patterns of cellulose particles, 267, 

 271, 274, 275 



Xylene: effects on dormant potato tubers, 234 



Xylenoxy acids: growth substance activity as af- 

 fected by their structure, 222 



Yarovization: wheat, 334 



Yellows diseases: (See Aster yellows; Peach yellows ; 

 Viruses) 



JCea mays, 60, 75 



Zizania, 91 



Zizania aquatica: 101 



moisture effects on life span, 31 



