740 



INDEX AND GLOSSARY 



dorsad: toward the back (not posterior end) 

 of an animal; thus, for a four- 

 footed animal, upward 

 douroucouli: Aotus, q.v. 

 Dove's experiment, 315* 

 DromcEus (bird: emu), pecten in, 649 

 dromedary (one-humped 'camel'), eye of, 



173 

 Dryophiops (close relative of Dryophis,q.v.) 



adaptations for binocular vision in, 299, 



fovea of, 186-187, 307 [307 



pupil of, 692 (entry for p. 221) 

 Dryophis (reptile: East Indian long-nosed 



accommodation in, 283, 299 [tree-snake) 



binocular vision in, 186, 293-294, 307 



cheek groove of, 185-186, 299 



dermal color change in, 542 



eye-movements in, 307 



fovea of, 185-188, 186, 307 



habits of, 178 



head of, 186 



independence of motion of prey, 344 



possible color vision of, 520 



probable color of lens in, 199 



pupil of, 185-186, 221, 293 



visual acuity of, 178, 637-638 



visual cells of, 178, 637-638 



visual fields of, 292-294 

 duck-bill: Ornithorhynchus, q.v. 

 ducks 



dabbling, ciliary muscles of, 441 



diving 



ciliary muscles of, 441 

 cornea of, 441 

 iris sphincter in, 440 

 nictitans-lens in, 440 



feeding habits of, 439 



torrent-, 439 



visual fields of, 295 

 Dufay, 503 

 Dugong (mammal: a sirenian) 



eye and habits of, 408-410, 409 



refraction of, 273 

 Dunlap, 692 (entry for p. 99) 

 Duplicity Theory, 64*, 65*-73, 657 



attacks upon, 215 



color-vision tenet of, 463-464 



photomechanical changes and, 149 



physiological evidence for, 70, 71-73, 149, 

 500 



visual-cell transmutation and, 163-168, 

 464-465, 497 

 dura mater (see meninges) 



eagle-rays: Myliobatidae, q.v. 

 eagles 



area and foveae of, 187, 307-308 



eye shape in, 642-643 

 feeding methods in, 439 

 oculorotatory muscles of, 642 

 pecten in, 643, 655-656 

 retina, area of, 656 

 scleral ossicles of, 270, 644 

 visual capacities of, 655, 662 

 earthworm, photoreceptors of, 3 

 echidnas (monotremes; see Tachyglossus, 

 behavior of, 185 [Zaglossus) 



circumlental space in, 284 

 eyes of, 664-671,667 

 lenses of, 284 

 lids of, 425, 427 

 visual cells of, 670-671, 688 

 ectoderm: outermost of the three germinal 

 cell-layers of an embryo (see endo- 

 derm, mesoderm) 

 ectopic: out of the usual place 

 edentates, 676* 

 Edridge-Green, 499 



eels (teleosts; see also Angullla, Gymnotidae, 

 Simenchelys) 

 campanula (lacking) in, 583 

 chorioid gland and pseudobranch (lack- 

 ing) in, 581 

 cornea and spectacle in, 450, 454 

 falciform process (lacking) in, 582 

 habits of, 372 

 life cycle of, 405-407 

 pupil in, 150, 220 



retinal vessels of, 51, 202, 204, 582-583 

 Egger's line, 10, 19* 

 Egyptians, reverence of cat by, 234 

 eikonogenesis, 3* 



Elapidse (reptiles: cobra-type snake family) 

 fossorial, spectacles of, 450 

 habits of, 201 

 pupil in, 221, 225 

 visual cells in, 201, 637-638 

 yellow lens in, 201 

 elasmobranchs: Elasmobranchii (lowest class 

 of true fishes, comprising sharks, 

 rays etc., and chimjeras); 563-569; 

 see also Batoidei, sharks, Holo- 

 cephali; 692 (entries for pp. 561, 

 568) 

 electric organ, evolved from eye muscles, 

 electric ray: Torpedo, q.v. [293 



eleCTroretinogram, 490* (see retina, photo- 

 electric phenomena of) 

 elephant-fishes: MormyridcE, q.v. 

 elephant-seal: Macrorhinus, q.v. 

 elephants 



cones of, 688 

 eye size in, 145 

 eye-movements in, 311 

 habits of, 145 



