796 



INDEX 



Cypris (Cypria), 152, 208 



composite ocellus of, 152 

 Cystoflagellates, 180 



D 



Dacelo gigas, pecten, 413 

 Dafila acuta, visual acuity, 663 

 " Dancing " of bees, 70 

 Daphnia, 74, 208 



composite ocellus of, 152, 209 

 compound eye of, 163, 209 

 conditioning of, 578 



dermatoptic sensitivity in, 32, 114, 578 

 dorsal light reaction in, 74 

 Darwin, Charles, 2, 3 

 Dasychone, ocelli of, 192 

 Dasypeltis, 392 



visual cells, 392 

 Dasypodida?, 445 

 Dasypus. See Armadillo. 

 Dasyure, 437, 438 

 ciliary muscles, 439 

 pupils, 439, 612 

 tapetum fibrosum, 438, 609 

 visvial cells, 440 

 Dasyuridse, 437 



See also Dasyure, Tasmanian devil, etc. 

 Decapods, 206 

 eyes of, 206 



nervous system, 521, 524 

 Decussation. See Chiasmal decussation. 

 Deep-sea crustaceans, eyes of, degenerate, 

 207, 723 

 enlarged, 207 

 luminous organs in, 740, 742 

 fishes, eyes of, degenerate, 292, 723 



enlarged, 273, 281, 292, 323, 606, 



723 

 stalked, 327 

 tubular, 277, 322, 606 

 optics of, 642, 643 

 luminous organs in, 741, 746 

 pupils, 286 

 refraction of, 638 

 retina, pure-rod, 310, 610 

 tapetum, retinal, 608 

 threshold to light, 674 

 visual acviity of, 657 

 cells, 305, 643 

 field, vmiocular, 670 

 molluscs, eyes of, degenerate, 723 



Deep-sea molluscs, eyes of, stalked, 203 

 tubular, 203 

 luminous organs in, 740, 742 

 Deer, 446 

 cornea, 453 



eyelids, movements of, 491 

 Harder's gland absent, 494 

 nictitating membrane, 493 

 optic axis, 688 

 visual acuity of, 664 

 Degenerate eyes, 721 

 Deiters' nucleus, 534 

 Delphinus. See Dolphin. 

 Demodex folliculorum, 216 

 Dendroccelum, 188 



klinokinesis in, 36, 37 

 ocelli of, 136, 188 

 Dendrocopus major, 414 



pecten, 414 

 Dendrocygna, iris, 407, 408, PI. XI 

 Dentalium, 197 



eyes lacking in, 729 

 statocysts of, 197 

 Depressor corneae. See Crampton's 

 muscle, 

 palpebrse inferioris, in elephant, 492 

 Depth perception, 667 

 Dermaptera, 218, 220 



See also Forficula. 

 Dermatopsia, 114 

 Dermatoptic sensitivity, 32, 113 

 of echinoderms, 184 

 of rotifers, 194 

 Derniochelys coriacea, 369 

 scleral cartilage, 370 

 Dermoptera, 443 

 Descartes, Rene, 710, 712 

 Desman, 441, 443 

 Desmid, 35 



response to light, 35 

 Desmodus. See Vampire bat. 

 Deuterocerebrum, in arthropods, 521 

 Diadema antillarum, 185 



colour changes in, 89, 90 



rhythmic, 20 

 dermal sensitivity in, 114, 185 

 iridophores in, 184 

 phototropic movements in, 39 

 setosum, iridophores in, 185 

 Dia-heliotropism, 38 

 Dialommus fuscus, double cornea, 325 

 Diatom, 35 



colour changes in, 82, 89 



I 



I 



