842 



INDEX 



Visual cells, development of, 243 

 lengthening of, 643 

 migration of, 614, 615 



rhythmic, 19 

 multiple, 253 

 origin of, 252 

 centres, evolution of, 543 



in mid-brain, 534 

 fields, binocular, 672 

 of amphibians, 682 

 birds, 682, 684 

 cyclostomes, 678 

 fishes, 678, 679 

 mamiTials, 687, 689 

 reptiles, 682 

 uniocular, 669, 670 

 illusions, 703 

 judgments, 700 

 orientations, 669 



pathways, cortical projection, 544 

 evolution of, 543 

 in amphibians, 537 



arthropods, 524, 525, 526 

 birds, 539 



cephalopods, 528, 529 

 cyclostomes, 535 

 fishes, 536 

 mammals, 540 

 reptiles, 538 

 pigments, 118 

 purple, 122 

 trident, 684 

 violet, 122 

 Vital spirits, 28 



Vitamin A pigment system, 120 

 in arthropods, 121 

 molluscs, 120 

 vertebrates, 121 

 Vitrellai, in compound eyes, 167 

 Vitreous, characteristics in 

 placentals, 476 

 selachians, 287 

 teleosteans, 304 

 Viverridse, 445 



pupils, 470, 471, 472 

 retinal vascularization, 479 

 Vizcacha, 442, 445 



pupils, 472 

 Vole, field-, 445 

 eye of, 450 

 red-backed, colour vision in, 633 

 Volvox, 179, 180 

 globator, klinotaxis in, 49 



Vorticella, 179, 180 



Vulpes. See Fox. 



Vulture, African, visual acuity of, 662 



W 



Walckenae7-a acuminata, eyes of, 214 

 Wallaby, 437, 440 



ciliary region, 439 



eye of, 438 

 Walls, Gordon, 352, 353 

 Walrus, 445 



ocular adnexa, 501 



pupils, 470 



See also Pinnipedes. 

 " Warning colours ", 631 

 Wasps, 219, 220 



digger-. See Philanthus. 



eyes of, 160 



mnemotaxis in, 79 



time-memory in, 22 



See also Vespa. 

 Water-beetle. See Dytiscus. 

 Water-fleas. See Cladocera. 

 Weasel, 445, 472 



pupils, 472 

 Whale, beaked, ciliary receptor organs, 467 



blue, 444, 446 

 eyes of, 449 



hump-back, 444, 446 



ciliary receptor organs, 467 

 sclera, 451 



killer, 446 



right-, 446 



sperm-, 444, 446 



See also Cetaceans. 

 Whelk. See Buccinum. 

 Whip-tailed scorpion, 214 

 activity of, 34 

 eyes of, 149, 150, 214 

 Whirligig beetle, 74 



accommodation, static, 591 

 orientation of, 74 

 See also Dineutus. 

 Winteria, tubvilar eyes in, 324 

 Wolf {Canis lupus), 445 



accommodation in, 653 



eye of, 447 



nictitating membrane, 493 



optic disc, 486 

 Wolverine, pupils, 472 

 Wombat, 437, 441 

 Wood, Casey Albert, 396, 397 



