782 



INDEX AND GLOSSARY 



Uta (reptile: an iguanid lizard), habits and 

 pale dermal phase of, 541 



uvea, uveal traa: chorioid + ciliary body + 

 iris, qq.v. 



vacuole: a small, fluid- (rarely, gas-) filled 

 cavity within a cell or (in loose 

 sense) in a tissue 

 Valentin, 183 

 Vanderplank, 502 

 Vanellus (bird: lapwing), embryonic head 



of, showing corneal sensills, 271 

 VaranidcB (reptiles: a lizard family whose 

 only living genus is Varanus, g.y.) 

 as ancestors of snakes, 632-634 

 Varanus (monitor lizards) 



area temporalis and fovea of, 187 

 chorioid of, 617 

 retina of, 625 

 size of, 293 



visual fields of, 293-294, 306 

 anterior blind cone of, 298 

 vascular, vascularized: supplied with blood 



vessels 

 ventrad: toward the ventral side (of an 

 Verrier, 215, 304, 586, 685 [animal) 



vertigo, disturbance of reflex eye-movements 



in, 301 

 Vipera (reptile: a viperid snake; common 

 conus papillaris of, 631 [adder) 



sexual difference in eye color of, 549 

 visual cells of, 640 

 visual fields of, 294 

 Viperidffi (reptiles: a snake family; Old- 

 World vipers) 

 habits in, 201 

 pupil in, 221, 225 

 visual cells in, 639-640 

 vipers: Viperidje, q.v. 



pit-: CrotalidcE, q.v. 

 Virchow, 657 



vision (see also binocular vision, color vision, 

 movement, sensitivity, space, visual 

 acuity, visual fields) 

 achromatic, 64-65* 



acute, diurnality and, 169-175, 464-465 

 after cataract extraction, 204 

 anomalous trichromatic (see color blind- 

 compensations for loss of, 388 [ness) 

 dependence on rhodopsin of, 75 

 latent period of, 350 

 multiplex, 198, 497, 502-503 

 photopic (see also Purkinje phenomenon), 

 64*, 81-103, 245 

 movement-perception in, 352-356 

 spectrum in, 87, 92-94, 101-102, 462- 

 refractory period of, 350-351 [464 



scotopic (see also Purkinje phenomenon), 



64*, 74-80, 245, 464 



in deep-sea environment, 395-403 



movement-perception in, 352-356 



spectrum in, 87, 91-92, 101-102 



suppression of, 348-349 



through 



air (see terrestrial artivity) 



air and water (see amphibious aaivity) 



fog etc., 197-198, 248 



water (see aquatic activity), 462 



tube, 214, 445 



with tapetum lucidum, 245-246 

 visual acuity, 53, 65* 



accommodation and, 283-284, 588 



in achromatic vision, 97 



in area and fovea, 181-190, 588 



binocular, 308, 331*-333 



in birds, 642, 661-662 



color vision and, 464-465, 493, 588 



color-filters and, 193-198, 204-205 



in deep-sea fishes, 398 



diurnality and, 169-175, 207, 209 



of human races, 190 



intensity and, 71-72, 80 



in man and animals, 207 (Table V), 246, 



in monochromatic light, 89 [662 



movement and, 174, 349-356, 365-367, 464 



nocturnality and, 206-207, 210-211 



optomotor reaction and, 302, 492-493 



retinal factors in, 65-68 



in sirenians, 409 



speed and, 174, 349-367 



stereoscopic, 3 3 1 * 



summation and, 67 



tapetum lucidum and, 245-246 



two-point limen of, 350 



voluntary eye-movements and, 303-312 

 visual axis, 7, 292* 



alterability of, 299-300, 405, 431, 624 

 (and see muscle, transversalis) 

 phylogenetic, 402-403 



of amphibious mammals, 443-444 



of whales, 413 

 visual cells (see also Plate I, p. 691) 



accommodation and, 30-31, 249, 253-254, 

 268, 281, 414-415 



ancestry and homologies of, 79, 163, 464- 

 465, 572-573 



in area and fovea, 181-184, 195, 692 

 (entry for p. 195) 



compared with half-tone, 332 



deficiency of, in achromasy, 97 



development of, 107-108 



in diurnal animals, 175-178, 177 



metabolic requirements of, 648-659, 672, 

 684 



migrations of, 146-148, 149-153, 160-163 



