898 



SUBJECT INDEX 



Photoperiodism (Continued) 



mechanism of, in reptiles, 674, 

 675 



metabolic aspects of, 289, 296 



relation to auxin, 468 



relation to chlorosis, 455 



relation to colored light supple- 

 ments, 352, 357 



relation to diurnal change of light 

 sensitivity, 538, 539 



relation to diurnal periodicity, 

 522,523,533 



relation to gibberellic acid, 351, 

 356,467 



relation to reproduction in in- 

 vertebrates, 625, 632, 634-637 



theoriesof, 315,317, 318 



threshold energy for, 457 



timing processes, 284, 522, 523, 

 532,533 

 Photophil, 525, 531, 534, 554 

 Photoreactivation, 541, 546, 548- 



550 

 Photoreceptors, 381, 562 



encephalic, 728-730 



hypothalamic, 728-730 



ocular, 728-730 

 Photoreversal, 448 



of biological clock by far-red, 444, 

 449, 450 



of chlorophyll formation, 467 



linear function of energy for, 463 



of photoperiodic induction by far- 

 red, 455 



of red effects by blue, 77, 78 

 Photosynthesis, 25, 26, 33, 35, 57, 

 65, 67, 290, 381 



action spectra of, 447-449 



effect on photoperiodism, 447 



effect of short days on, 292 



in flowering, 382 



in nutrition of dlnoflagellates, 567 

 Phototaxis 



action spectra of, 29-3 1 

 Photothermal control 

 of flowering, 357 

 of growth, 357 

 Phototropism 



action spectra of, 447, 449 

 Pigment 



content in relation to diurnal 

 periodicity, 538 

 Pigment 



photoperiodic, 246, 412 

 decay of, 251,252 

 Pigments 



absorption spectra of, 1 5 

 identification in ceUs, 15, 22 

 optical properties of, 15 

 particles of, 17 

 Pineal body, 673, 675 

 Pitcher-plant, see Metriocnemus 



Knabi 

 Pituitary 



in fish, 664, 665 

 Pituitary tropic hormones, 841 

 Poisons 



influence on diurnal periodicity, 

 519,520 

 Portal system 



hypothalamo-adenohypophysial, 

 729,730 

 Prorocentrum 



action spectrum for phototaxis, 

 31 

 Protochlorophyll, 26-29, 32-34 

 Psychic factors 



in sexual development in females, 

 736,737,739 

 Pteridine 



absorption spectrum, 324, 326 

 column chromatography, 322, 



326 

 fluorescence spectrum, 322, 324, 



326 

 paper chromatography, 322, 326 



