822 



INDEX 



Parietal organ, accessory, 715 



function of, 719 

 Parrots, eyelids, 424 



eyes of, 399 



ocular movements of, 696 



reproductive cycle in, 17 



visual field, binocular, 684, 685 



See also Chrysotis. 

 Pars intercerebralis, in insects, 555 

 Parus, panoramic vision in, 683 



visual acuity, 663 

 Passer domesticus, 408 



ciliary venous sinus, 408 



colour vision of, 630, 632 



orbit and brain, 424 



reprodvictive cycle in, 17 



summation, retinal, 660 



visual acuity of, 662 

 cells, 419 

 Passeriformes, accommodation in, 651 



bifoveate retina, 418 



eyes, shape of, 402 



pecten, 412 



time-memory in, 22 



See also Corvidse, Hirundo, Passer, etc. 

 Passerita prasina, 674 

 iris, PI. IX 

 pupil, 388, PI. IX 

 visual field, binocular, 684 

 Patella, 197 



homing ability of, 575 



ocelli, 137, 197 

 Paurangiotic retina, 480 

 Pauropus, 211 



eyes lacking in, 729 

 Pearl-fish. See Encheliophis. 

 Pearly nautilus. See Nautilus. 

 Peccary (Dicotyles), 445, 458 



See also Suoidea. 

 Pecora. See Ruminants. 

 Pecten of birds, 410 



function of, 415 



histology of, 414 



pleated type, 411, 412 



vaned type, 411 

 Pecten (scallop), 200 



ocelli of, 148, 200 



sensory reactions of, 103 



vision of, 575 

 Pectinate ligament, characteristics in 

 chelonians, 372 

 crocodilians, 376 

 lacertilians, 359 



Pectinate ligament, characteristics in 

 marsupials, 439 

 placentals, 463, 464, 469 

 Pectunculus, ocelli of, 151, 201 

 Pediculus, 218 

 ocelli of, 139 

 scototaxis in, 60 

 Pedipalpi, 214 



See also Whip-scorpions. 

 Pedunculate body, in arthropods, 521, 524 

 Pelagia, my o -epithelial cells in, 513 



noctiluca, bioluminescence in, 739, 744, 

 745, 748 

 rhythmic, 22, 747 

 Pelecanus, 410 



conspic Hiatus, fundus, 410 

 Pelobates fuscus, pupils, 339 

 Pelomyxa, effect of light on, 7 



latent period in, 36 

 Penguin, 398 



rock-hopper. See Eudyptes. 

 See also Impennes. 

 Peragale. See Bandicoot, rabbit, 

 Perameles. See Bandicoot. 

 Perca, ocular movements of, 692 



fluviatilis, optomotor reaction of, 706 

 Perception of colour, 619 

 depth, 667 

 form, 637 

 light, 602 

 movement, 705 

 size, 667 

 space, 666 

 Perch. See Perca. 



climbing. See Anabas. 

 Percidse, retinal tapetum in, 305, 612 



See also Perca, Lucioperca. 

 Perichceta, phototaxis, in, 45 

 Periophthalmus, 326, 694 

 accommodation in, 655 

 annular ligament, 295, 296 

 eyes of, 326 



ocular movements of, 694 

 Peripatopsis alba, degenerate eyes of, 724 

 Peripatus, 139, 204 

 nervous system, 521 

 eyes of, 138, 205 

 Periplaneta, response to light of, 34, 114 

 Perissodactyla, 446 

 pupils, 472 



retinal vascularization, 480 

 See also Equidae, etc. 

 Periwinkle. See Littorina. 



