INDEX AND GLOSSARY 



Hippopotamus 

 adnexa of, 443 

 compared with sirenians, 408 

 elevation of eyes in, 443 

 eyelashes of, 426, 443 

 habits of, 443 

 lid-movements of, 425 

 pupil of, 221, 443 

 taxonomic position of, 139, 676 

 vision of, 311, 408 

 Hogben, 535, 538 



Holocephali (elasmobranchs: chimeeras) 

 habitat of, 392, 563 

 ocular shape in, 565 

 oculorotatory muscles in, 564 

 pupils of, 220, 222 

 retina in, 399-400 



summation of, 568 

 sclera in, 416 

 tapetum (lacking) in, 240 

 taxonomic position of, 135-136 

 visual cells of, 568 

 Holostei (holostean fishes — Amia + Lepis- 



osieus, qq.v.), 573-576 

 HomalopsincE (reptiles: a colubrid sub- 

 family — river snakes) 

 binocular field of, 293 

 elevation of eyes in, 438 

 spectacles of, 450 

 value of vision to, 293-294 

 homologous — homoiologous : homology con- 

 notes evolutionary derivation from 

 a common-ancestral strurture — 

 homoiology, evolutionary derivation 

 from non-contemporaneous portions 

 of a struaural substrate; thus: if 

 structures A and B (whether alike 

 in form and/or function or not) 

 were derived ancestrally from struc- 

 ture C, then A and B are homol- 

 ogous (with each other and with 

 C); but if A and B were derived 

 respeaively from strurture C and 

 from strurture D (D being an un- 

 modified descendant of C), then 

 A and B are homoiologous. 

 honey-birds, preference for red flowers by, 

 Honigmann, 498 [503 



Hopkins, 510-511 

 Horio, 489-490 



hornbill, ocular mobility of, 307 

 horned 'toad' : Phrynosoma, q.v. 

 horopter, 317* 

 horse 



accommodation (lacking) in, 255, 285 

 color vision in, 505 

 eye of 



ramp retina in, 255 



size of, 171, 173, 211 

 fixation by, 3 1 1 

 gait of, 352 



interpupillary distance of, 327 

 movement-perception by, 354 . ^ 



nirtitating membrane of, 427 

 optic axes of, 297 

 optic chiasma of, 319 

 pertinate ligament of, 680 

 pupil and iris of, 2 1 8, 227, 679 

 refrartion of, 287 

 retinal vessels of, 684 

 retrartor bulbi of, 420 

 taxonomic position of, 676 

 vision of, 246, 505 

 visual fields of, 289, 297-299, 354 

 Hosch, 589 



Hottentots, visual acuity of, 190 

 Howell, 442-443 



Hubbs, 202, 392, 402, 460, 548 

 hue: color in the strirtest sense — i.e., without 

 regard to variations in brightness 

 and saturation; thus: red and pink 

 are different colors, but the hue 

 of both is red 

 human eye (and vision; see also vision), 7-8, 

 10, 14-15, 27, 31, 35, 37, 39, 43- 

 44,47,54-55,82,87,91,94, 101- 

 102, 105, no-Ill, 173, 182, 194, 

 252,316, 321, 332, 335, 359,683 

 accommodation and refrartion of, 30-36, 

 31, 35, 272-273, 440, 285-287, 

 682-683, 689 

 refrartive errors, 26, 27-28, 194 

 adnexa of, 36-41, 37, 39 

 anomalous eyeshine of, 241 

 cornea of 



biomicroscopy of, 452-453 

 relative area of, 289 

 dioptrics of, 29-30 

 fibrous tunic of, 672 

 fovea of, 7, 181-182, 190, 661, 689 

 interpupillary distance of, 327 

 lens, color of, 191, 199, 202, 204-205 

 movements of, 300-303 

 optic chiasma of, 47, 52 

 resolving power of, 207, 662 

 retina of, 43, 684 

 area of, 289 

 area of image on, 2 1 1 

 blind zone of, 289 

 summation of, 661 

 vessels of, 684 

 shape of, 672, 677 



structure of, 6-22, 285, 674, 678-683, 689 

 visual angle of, 289, 297 

 visual cells of, 43, 54-55, 685-686, 688- 

 visual process in, 74-99 [689 



