826 



INDEX 



Polypterini, 235, 278, 315 



eyes of, 320 

 Polypterus, 278, 320 



eyes of, 320 



median eye of, 713 

 Polyzoa, 194 



larva, ocelli of, 195 

 Pomolobus, eyelids in, 311 

 Pongo. See Orang-utan. 

 Pontellopsis regalis, eyes of, 159, 209 

 Popillia, response to light, 34 

 Porcupine, 442, 445 



colour blindness of, 633 



eye of, 447 



optic axis, 688 



retinal vascularization, 480 

 Porichthys, luminous organs of, 746 

 Porifera. See Sponges. 

 Porphyropsin, 122 

 Porpoise, 446 



cornea, 453 



See also Cetaceans. 

 Porthesia caterpillar, phototaxis in, 46 

 Portunus, colour changes in, 92 

 Postural reflexes, 690, 691 

 Potamilla, ocelli of, 192 

 Potamogale. See Shrew, otter-. 

 Potto, 443, 607 



See also Lemuroids. 

 Pouchetia, eye -spot of, 126 

 Prairie-dog, 445 



pupils, 472 



visual cells, 482 

 Prawns, 166 



eyes of, 163, 206 



luminous organs of, 742 



See also Hippolyte, Palmynon. 

 Praying maiitis. See Mantis religiosa. 

 " Preference " technique, 568 



colour vision and, 623 

 Primates, 443 



accommodation in, 654 



angle gamma of, 677 



area centralis, 485 



canal of Schlemm, 473 



cerebral cortex, 543 

 removal of, 545 



chiasmal decussation, 487, 698 



ciliary cleft, 463 

 muscle, 462 

 processes, 467 

 region, 460, 463 



colour vision of, 635 



Primates, diurnal, 604 



extra.-ocular mvxscles, 495 



eyes of, 450 



fovea, 486, 659 



harderian gland, 494 



iris vascularization, 468 



lateral geniculate body, 489, 490, 541 



lens, 474 

 capsule, 653 

 svitures of, 474, 475 



Moll's glands, 492 



neviro-endocrine system, 557 



nictitating membrane, 493 



nocturnal, 604 



occipital cortex, removal of, 546 



ocular movements of, 696 



orbit, 498 



pectinate ligament, 464 



pineal organ, 715 



pulvinar, 542 



pupils, 471 



reactions of, consensual, 700 



refraction of, 639 



retina, 483, 616 



vascularization of, 477, 479 



retractor bulbi, 495, 496 



spatial judgments of, 704 



summation, geniculate, 611 



vision of, 601 



visual acuity of, 663, 664 

 cells, 482,' 483 

 field, binocular, 689 

 uniocular, 670 



zonular fibres, 475, 476 

 Pristis, 279 

 Proboscidea, 446 



See also Elephants. 

 Procellaria pelagica, 420 



green oil-droplets, 420 

 Proctacanthns, circus movements in, 54 



telotaxis in, 59 

 Procyon. See Raccoon. 

 Procyonidse, 445 



pupils, 471, 472 

 Pronghorn, lacrimal gland absent in, 493 



See also Ruminants. 

 Propithecus, diurnality of, 604 

 Prosencephalon. See Fore-brain. 

 Prosimians, 443 



area centralis, 485 



diurnal, 604 



eyes, shape of, 448 



iris pigmentation, 469 



