INDEX 



783 



Arachnids, luminous organs in, 740 

 neuro -endocrine system, 552 

 vision of, 579 

 visual centres, 524 

 Araneida, 213 

 eyes of, 213 

 nervous system, 521 

 vision of, 579, 591 

 Araneus diadematus, 214 



eyes of, 213 

 Area, eyes of, 151, 201 



light -shadow reflex in, 574 

 Archiannelids, 190, 193 



ocelli of, 193 

 Archicortex, 543 

 Archistoma, eyes of, 221 

 Arctocebiis. See Agwantibo. 

 Ardea, 404 



goliath, binocular vision, 675 

 Area centralis, characteristics in 

 anurans, 342 

 birds, 417 

 chelonians, 374 

 crocodilians, 377 

 lacertilians, 365 

 placentals, 485 

 selachians, 288, 289 

 teleosts, 309 

 function of, 657 

 occurrence of, 657 

 Arenicola marina, 190 

 diffuse sensitivity of, 191 

 eyes lacking in, 729 

 larva, tropotaxis in, 52 

 visvial pigment in, 120 

 Argentea, characteristics in 

 chondrosteans, 317 

 holosteans, 321 

 lamprey, 267 

 Latimeria, 315 

 selachians, 285 

 teleosts, 296 

 function of, 296 

 Argyropelecus, 322 



eyes of, tubular, 323. 324 

 luminous organs, 741 

 rods, lengthening of, 611 

 Arhythmic animals, 603 



eye, characteristics of, 612 

 Ariolimax, optic ganglia, activity of, 



524 

 Aristelliger, triple cones in, 308, 364 

 Aristeomorpha, photopigments in, 121 



A rniad ill id i urn , 4 5 



tropotaxis in, 54 



alteration of resjionse, 45 

 Armadillo, 442, 445 



cornea, keratinized, 456 



pineal body absent ,711 



retina, jjure-rod, 610 



visual cells, 482 

 Arrow-worms, 194 



See also Sagitta, Spadella. 

 Artemia, 207 



dorsal light reaction in, 75 

 Arteria anastomotica in placentals, 498, 



499, 500 

 Artery, central retinal, 477 

 Arthrojiods, 204 



blind, 729 



cerebral ganglion, 521 

 activity of, 524 

 function of, 524 



eyes of, 204j^. 



degenerate, 724, 729 



luminous organs in, 740, 746 



nervous system, 521 



neuro -endocrine system, 550, 552 



vision of, 577 



^ee cdso Insects, Crustaceans, etc. 

 Artiodactyla, 445 



area centralis, 485 



orbit, 497 



I^upil, 472 



See also Pig, Deer, etc. 

 Ascaris, 187, 190 

 Ascidia, 228 



larva, 228 

 Ascidians. 228 



bioluminescence in, 740 



eyes of, 228 



larvse, eyes of, 228 



nervous system, 519, 530 

 vertebrate eye developed from, 245 



nervous system, 519, 530 



neuro-endocrine systeni, 552 

 Asellus, 207 



conditioning of, 579 



eyes lacking in, 207, 722 

 Asio, infra-red rays and, 630 

 Asplanchna, dermatoptic sensitivity in, 32 

 Ass {Eqnus asinus), 446 



corneal epithelium, 452 



corpora nigra, 469 



extra-ocular muscles, 495 



nictitating membrane, 493 



