764 



RADIATION BIOLOGY 



Summation-of-stimulus law (Talbot's 



law), 524 

 Sun, 152-157 



air mass, 153 



intensity, 155 



solar constant, 152 



spectrum, 154 



time of rise and set, 156-157 

 Superposition type of compound eye, 648 

 Swiss chard, 360 

 Syllis, ocellus, 634 



Symbionts and photosensitivity, 628 

 Synapiula, mutilated, photic responses, 

 662 



Tachycines, flicker-fusion rate, 649 



Talbot's law, 524 



Talbot-Plateau law for flickered light, 



668». 

 Tapetum, in arthropod ommatidia, 648- 

 649 

 in insect ocelli, 645 

 in secondary ocelli of spiders, 644 

 Temperature, color, 151 



effect of, on fluorescence, 311 

 on photoblastism, 521-523, 537 

 on photosensitivity, 523-524 

 on photosynthesis, 297 

 on product law, 524 

 pretreatment with, 530-531 

 radiation, 151 

 Tetrahydroporphin, 95 

 Tetraphenylporphins and chlorins, 111 

 Theridion, visual identification, 669 

 Thermocouple, 225 

 Thermodormancy, 522-523 

 Thermopile, 221,' 225 

 Thermosensibilization, 521 

 Thermosensitivity change, 542 

 Thiohacillus, 322, 329 

 Thiochloraceae (green sulfur bacteria), 



298, 302, 306, 341, 371, 372 

 Thiorhodaceae (see Purple sulfur bac- 

 teria) 

 Thiophene chains, 95 

 Thiosulfate, 298, 312 

 Thiourea, 527, 537 

 Thyone, orientation to light, 662 

 Tiger beetles, distance estimation, 653 

 Time constants for light absorption and 



emission, 83, 84 

 Time lag, 283-285 

 Titration for oxygen, 280 

 Tomo-ptcris, photoreceptors, 635 

 Tonus, 465 



Toxopneustes, photic responses, 661 

 TPN, 459, 460 



TPNH, 459, 460 



Trachelomonas, photosensitivity, 626 



Trajectories, collision, 21 



for intramolecular energy migration, 30 

 for vibrational excitation, 25 

 Transition matrix element or moneiit, 76, 



102, 107, 108 

 Transition probability coefficients, 4 

 Transitions, optical, 11 

 probability of, 12 

 radiationless, 11 

 Transmission, 464 



(See also Absorption) 

 Transmission coefficient, 22, 52 

 for electronic processes, 40 

 in intramolecular processes, 32, 33 

 Transmittance, conversion to absorb- 



ance, 254 

 Transmittancy, 146 

 Transpiration, 445 

 Transport, lateral, 466, 472-474 

 Trefoil dermatitis, 709, 715 

 Tribonema, 306 

 Tridacna, false eyes, 639 

 Trifolium repens, 353 

 Trilobites, blind, 658 



compound eyes, 646, 656 

 growth indications, 656 

 regeneration of, 654 

 ocelli, 644 



probable inverted swimming, 644 

 Triops, compound eyes, 656 

 Triphosphopyridine nucleotide, 322, 450 

 Triplet states, 81, 86, 87 

 of chlorophylls, 114 

 photochemical reactions, 117, 118 

 Triplicity theory of arthropod compound 



eye, 652 

 Trypsin, 528, 536 

 Turban-style compound eyes, 652 

 Turgor movements, 463 



U 



Uca eye, vitamin Ai, 624 

 Ulbricht sphere, 265 

 Ultraviolet light, 294, 333 



sensitivity to, in Anthrenus larvae, 666 



in Apis, 667 



in crustaceans, 665-666 



in Danaus caterpillar, 666 



in insects, 665 



in nematodes, 631 



in protozoans, 625 



in turbellarians, 629-630 

 Ulva, 310 



taeniata, 360, 361, 363, 364 

 Unimolecular reactions, 29 

 theory, 32-34 



