SUBJECT INDEX 



897 



Paramecium, 542 

 conjugation in, 541 

 matins reaction in, 541 

 sexual reactivity in, 541 

 Parietal eye, 673, 675 

 Periodicity, natural 



of Gonyaiilax rhythms, 573-577 

 Periodogram, 803, 805-811, 816, 



818,832,835 

 Perturbation 



bylight, 578, 579 

 Phase 



of rhythms in Gonyaulax, 573 

 Phase shift 



Gonyaulax rhythm, 577-581 

 induced by ultraviolet, 541, 548, 



549 

 induced by visible light, 546, 548- 

 550 

 Phospholipid, 826-828, 845, 847 

 Photochromoperiodism, 357 

 Photomorphogenesis, 103-108,453 

 action spectra of, 447, 449, 455, 



458, 466 

 induction of, 450 

 log-energy response, 460 

 photoreaction of, 423-428, 431, 

 432 

 reactants in, 43 1 

 pigment, 425, 427-430, 433-437 

 absorption coefficients of, 430 

 pigment conversion in, 428-430 



quantum efficiency for, 430 

 reversibility of reactions, 423 

 spectral dependence of, 101, 102 

 temperature coefficient of reac- 

 tions, 426 

 threshold energy for, 457 

 time-energy relation for, 457 

 Photoperiod; see also Day length; 

 Photoperiodism 

 critical 



oi Acronycta, 618 

 of Bomhyx, 618 

 of Diataraxia, 6 1 8 

 of Graplwlitha, 61S 

 of Macrosiphum, 618 

 Photoperiodic induction 



influence of auxin and gibberellin, 

 329-350 

 Photoperiodicity 

 fowl 



artificial photoperiods, 768- 



775 

 continuous lighting, 774, 775 

 diurnal periodicity, 780 

 effect on breeding season, 



768 

 effect on egg production, 767- 



772 

 effect of intermittent lighting, 



770,771,775 

 effect on lay behavior, 767-776 

 effect of radiant energy, 771, 



772 

 effect on time of lay, 773-776 

 exceptional photoperiods, 773- 



775 

 natural photoperiods, 768, 773 

 oviposition, 777, 778 

 ovulation, 776-782 

 photoperiod and activity, 772, 



775 

 role in timing ovulation, 776 

 Photoperiodism; see also Flowering 

 action spectra for, 449, 458, 467 

 in birds, gallinaceous, 751-757 

 effect of interruption of photo- 

 period cycle, 469 

 effect on rooting, 229-231 

 in insects and mites, 585-598 

 intensity-time relationship, 457 

 interrelationship with gibberellic 

 acid, 231 



