SUBJECT INDEX 



757 



Permeability of cells, influence of visible 

 light on, and intake, of organic 

 compounds, 561, 565 

 of salts, 557-559, 563, 564 

 of water, 558-559 

 methods of determination, absorp- 

 tion of dyes, 566 

 absorption of poisonous sub- 

 stances, 567 

 chemical analysis, 562 

 electrical resistance, 567 

 plasmolj^tic, 559 

 turgor, 561 

 nature of effect, 570-573 

 physiological consequences, 573 

 Peroxydase, 536 



Perturbations, by aza nitrogen, 92 

 by solvents, 85, 91, 115 

 by substituents, 88, 89, 102 ff. 

 Phacelia tanacetifolia, 519, 522, 525, 528, 



529, 533, 534 

 Phaeomonas, 302, 373, 515 

 Phalangida, ocelli, 645 

 Phaseoleus sp., 350 

 Phenothiazine keratitis, 705, 709 

 Phenyl butadiene, 95 

 Phenyl polyenes, 72, 79, 81, 87, 93-95 

 Pheophytins, absorption spectra, 354, 355 



structural formula, 400 

 Pheretima, photosensitivity, 635 

 <J>, 262 



Philanthus, conditioned responses, 670 

 Phleum pratense, 523, 529, 531, 532 

 Pholas, latency of photic response, 664 



photosensitivity, 638 

 Phormidium sp., 357, 358 

 Phosphate metabolism and photosyn- 

 thesis, 295, 299, 328-330, 334, 341 

 Phosphoglyceric acid, 317, 319, 320, 328 

 Phosphopyruvic acid, 317, 319 

 Phosphorescence, 11, 83, 84, 114 

 in gelatin suspensions of dyes, 57 

 lifetimes, 84 

 quenching, external, 85 

 Phosphorus (P^^)^ 329 

 Photoblastism, definition, 520 

 influenced by chemicals, 527-529 

 negative and positive, 521 

 Photocell (see Detectors of radiant 



energy) 

 Photochemical reaction, 129 



in photosynthesis, 299, 310-315, 321, 

 322, 334 

 Photochemistry, of porphyrins, theo- 

 retical, 117, 118 

 principles of, 260-263 

 Photoconduction, 57 

 "Photodinesis," 575 



Photodormancy, definition, 520 



induction, 529-530 



{See also Dormancy) 

 Photodynamic action, activation of 

 oxygen, 698 



active sensitizer compounds, 699 



augmentation by cyanides, 701, 712 



dark action, 700 



definition, 694 



effect of concentration of reactants, 698 



effects on skin, 704 



energy requirements, 696, 699 



fluorescence, 698, 701 



in human ailments, 715 



influence of temperature, 697 



inhibiting factors, 701 



mechanism, 694-701, 718 



peroxides in, 699, 718 



substrate in, 703 



sunburn and, 704 

 Photoinactivation, 468, 469 



of enzymes, 542 

 Photoisomerism, 13, 86, 94 

 cis-trans Photoisomerism, 87 

 Photolysis, 457 



of ethane, 34 



factor influencing product yield, 34 



of iodine, 34 

 Photometric units, 136-137 

 Photometry, 127 

 Photomultiplier, 234-236 

 Photon, 131 

 Photon energy, 261 

 Photonastic, 463 

 Photooxidation, 328 

 Photoperiodic response, 543 

 Photoperiodism, 479-517 



action spectra, 486-490 

 typical curves, 487 



aftereffects, 499-502 



animal response, 481-483 

 diapause, 482 

 migration, 480, 508 

 pelage change, 482 

 plumage change, 482 

 reproduction, 482 



animal types, 481 



auxin effects, 502-504 



discovery, 480-481 



environmental influences, 506-509 



inheritance, 504-506 



organs involved, 483-484 



period involved, 484-485 

 darkness interruption, 485 



photoreaction, 492-493 



plant types, 480, 489 



reciprocity, 493-495 



thermal reaction, 491 



time measurement, 491-492 



