756 



RADIATION BIOLOGY 



Ocelli, of pseudoscorpions, 645 



of pycnogonids, 645 



of Ranzania, 634 



of Sagitta, 632 



of Salpa, 662 



of Scolopendra, 634 



of scorpions, 645 



of Scutum, 634 



of solpugids, 645 



of spiders, 644 



of Spondylus, 639 



of Syllis, 634 



of trilobites, 644 



of turbellarians, 629 

 Ocellus, compound, definition, 625 



definition, 624 

 Octopus eye, in moving visual field, 668 



myopia, 641 



pigment change, 623 

 Oculomotor movements, in cephalopods, 

 641 



in Daphnia, 656 

 Ocypoda, binocular field, 652 

 Odd-atom systems, electronic structure 



and spectra, 73, 79, 80, 91 

 Odonates, distance estimation, 653 

 Oenothera, 529 



biennis, 522 

 Off-response, in amphineurans, 637 



in oligochaetes, 636 



in Pecten, 638 



in pelecypods, 638 

 Oligofhaeta, neuronal photoreceptors, 

 635 



photosensitivity, 635-637 

 Ommatidial divergence, 651 

 Ommatidium, definition, 624 



variation in structure, 647 

 Onchidium, accommodation, 641 



dermal photosensitivity, 641 

 (Jne-quantum process, 287 

 Oniscus, compound eyes, 655 

 Ophiocoma, photic responses, 660 

 Ophiuroidea, photosensitivity, 660 

 Optic nerve impulses (see Nerve 



impulses) 

 Optic tract, electrical responses, 606 

 Optical activity of protochlorophyll, 406 

 Optical density, 347, 363 

 Orbital energies, comparison with obser- 

 vation, 79 

 degenerate, 86, 99 

 effect on, of molecular size, 89, 90 



of twist, 86 

 noiibonding, 92 

 Orbitals (see Wave functions) 

 Orientation accuracy in starfish, 659-660 

 Oscillator strength, 76, 84 

 Oscillatoria sp., 365, 366 



Ostracods, compound eyes, 656 

 Oxaloacetic acid, 319, 320 

 Oxidation reduction, 539-540 

 Oxidation-reduction (redox) potential, 



299, 321, 324-328, 334, 341 

 Oxidation-reduction (redox) system, 316, 



322, 325 



Oxygen, 270, 285 



dissolved, 266 



concentration of, 285 

 influence of, on fluorescence, 312, 313 



on photoblastic reaction, 528, 537 

 by magnetic moment, 283 

 permeability of coats to, 541 

 polarographic determination, 267, 284 

 production in photosynthesis, 296, 297 



source, 297, 298, 341 

 (See also Hill reaction) 

 Oxygenic, 297, 322 



Panulirus, neuronal photoreceptors, 642 

 Papayotin, 528, 536 



Paramagnetic substances, effect on phos- 

 phorescence, 85 

 Paramecium, photosensitivity, 626 

 Parasorbic acid, 528 

 Partition function for collision complex, 



22 

 Patella, ocellus, 634, 640 

 Pecten ocellus, double retina, 638, 639 



pigment change, 623 

 Pectinatella larvae, photosensitivity, 637 

 Pectunculus, compound eyespots, 639 

 Pedipalpida, ocelli, 645 

 Pelargonium, 528 



zonale, 350 

 Pelecypods, photoreceptors, 638-640 

 Peranema, dark and light adaptation, 664 



photosensitivity, 628 

 Perichaeta, photosensitivity, 635 

 Periplaneta, flicker-fusion rate, 649 



role of ocelli, 646 

 Permeability of cells, 447, 541, 542 

 influence of visible light on, 557-574 

 connection with viscosity of proto- 

 plasm, 573 

 dependence of, on changes in light, 

 568 

 on pH, 563 



on solubility in lipoids, 565 

 on test object and permeating sub- 

 stance, 565 

 different kinds of light, 562, 567 

 different kinds of object, 567 

 direct influences, 558 

 energy relations, 563 

 indirect influences, 557 



