784 



INDEX 



Ass, Somali wild, 686 



See also Equidae 

 Astacus, 164 



eyes of, 164 



nervous system, 521 

 Astaxanthin, 120 



absorption spectrum of, 120 



in Euglena, 48 

 Asterias, 185 



phototactic reaction of, 571 



visual organs of, 185 

 Asteroidea, 184 



See also Starfishes. 

 Astroscopus, 751 



electric organ of, 751, 752 



sclera, 292 



visual field, binocular, 680 

 Astur palumbarius, 403 

 ciliary region, 406 

 scleral ossicles, 403 

 Ateles. See Monkey, spider. 

 Atherina, 617 



colour preference in, 625 



threshold to light, difference, 617 

 Auditory centre, in vertebrates, 534 



sense, of bats, 601 

 dog, 601 

 fishes, 598 



cave-, 726 

 insects, 581 

 spatial judgments and, 667 

 Auks, accommodation in, 643 



nictitating membrane in, 424 

 Aurelia, 183 



phototactic reactions of, 571 



aurita, sen.se organs, 183 

 Austrolethops, degenerate eyes in, 726 

 Autochthonous layer of cornea, 295 

 Auxins, 39, 510 



isolation of, 41 

 Averna sativa (oat), phototropism in, 40, 



119 

 Avicula, 200 



light-shadow reflex in, 574 



sense organs, 200 

 Axolotl, 346 



perception of movement in, 705 



visual cells, 348 



B 



j8-carotene, 119 

 Baboon, 443 



Baboon, colour vision in, 635 



refraction of, 639 

 Bacteria, luminous, 737, 743 

 Bacterium photometricum, activity of, 34 

 Badger (Meles), 444, 445 

 Balcena. See Whale, right-. 

 Balcenoptera. See Whale, blue. 

 Balanoglossus, 227 



nerve-net, 515, 530 



nervous system, 517, 530 



sense organs, 227 

 Balanus, 209 



adult, degenerate eyes in, 722 



larva, eyes of, 209 



shadow-reflex in, 45 

 Balistes, fovea of, 310 

 Bandicoot, 441 



nictitating membrane, 441 



pupillary flocculi, 439 

 Barathronus, degenerate eyes, 724 

 Barbatula, colour preference in, 624 

 Bathothaunut , 203 



stalked eyes of, 203 

 Bathygohius, interocular transfer in, 698 

 Bathylagus benedicti, 310, 323 



fovea, 310, 611 



visual cells, 305, 611 

 Bathypterois, " feelers " in, 724 

 Bathyteuthis, eyes of, 146 

 Bathytroctes, fovea, 310 



visual cells, 305 

 Batoidei, 279 



eyes of, 282 



See also Selachians, Raja, Torpedo, etc. 

 Bats, 443 



eyelids, 491 



eyes of, 449 



hearing in, 601 



lens, 606 



nictitating membrane, 493 



ocular movements of, 696 



optic axis, 688 



refraction of, 639 



retina, pure-rod, 610 



retinal vascularization, 480 



vision of, 601 



visual cells, 482 

 Bdellostoma, eyes of, 263, 734 

 Bears, 445 



nictitating membrane, 492, 493 



optic axis, 688 



polar, pupils, 471 



pupils, 471 



