INDEX. 



1595 



Visual sensations, discrete, conditions 



of, 1217 



,, in relation to visual percep- 

 tions, 1261-1271 

 ,, simultaneous, 1261 

 ,, substances,hypothetical, 1256, 1257 

 ,, units, retinal, 1219 

 Vitelliu, a constituent of yolk, 1491 

 Vitreous humour, the, 1167, 1308 

 Vocal cords, structure, 1451 



,, ,, voice produced by vibration 



of the, 1444, 1453 

 ,, ,, tightening and slackening of 



the, 1460 



Voice, the, 1444-1470 

 ,, how produced, 1444 

 ,, fundamental features of the, 1454 

 different qualities of, 1464 

 ,, chest and head voices, 1467 

 ,, registers of the, 1469 

 ,, breaking of the, 1470 

 Volkmanu, his haemadromometer, 220 

 Voluntary movements, their tetanic cha- 

 racter, 140 

 ,, ,, nervous mechanisms for, 



914, 1034, 1056, 1066 

 Vomiting, mechanism of, 460 

 Vowel chamber, 1471 

 Vowels, how formed, 1472 



Walking, how effected, 1481 



Walls, vascular, their influence on tran- 



sudation, 504, 506 



Warmth, its effect on skin action, 675 

 Waste matters, their discharge from the 

 living body, 2 



,, ,, given out by amoebae, 4 



,, ,, not necessarily useless, 43 



,, ,, elimination of, 632 



,, nitrogenous, 102 



,, ,, not increased by muscle 



contraction, 103, 106, 

 805 

 Water, secretion of, by the glands, 416 



,, varying amount of, in living tissue, 

 507 



,, its absorption into the portal sys- 

 tem, 513 



,, intestinal secretion of, 522 



,, its discharge by the kidney, 674 



by the skin, 699 

 Waves of contraction, muscular, 86 



,, pulse, dicrotic, their nature, 266 



,, ,, predicrotic, 270 



,, ,, anacrotic, 271 



of sound, 1318, 1362 



of light, 1222 



Waves of nervous and muscle impulse, 125 



Wax of the ear, secretion of, 693 



Web of frog, arterial changes visible in, 



306 



Weber's law, 1211, 1364, 1413 

 Weight, human, curve of, 1542 

 Wharton's jelly, 1515 

 Whispering, how effected, 1474, 1479 

 White, sensation of, produced from mix- 

 ing of colour sensations, 1228 

 Willis, circle of, 1131, 1134 

 Winking, how effected, 1310 

 chief use of, 1313 



Wolffian bodies, the origin of the con- 

 ducting part of the testis, 1502 

 "Word-deafness," 1089 

 Work, mechanical, in living body, 2 



,, done by a muscle-nerve prepara- 

 tion, 136 et supra 



,, amount done by heart, 253 



,, daily, estimate of, 803 



,, mechanical, source of energy of, 

 805 



,, production of heat increased by, 

 813 



Xanthin, a constituent of urine, 650, 758 

 ,, present in the thyroid, 762 

 )i ,, ,, thymus, 768 



Xanthoproteic test for protein, 17, 18 



Yawning, 630 

 Yellow elastic fibres, 190 

 ,, spot, structure, 1204 

 ,, ,, colour sensations as affected 



by, 1244 



Yolk, chemical composition of, 1494 

 Young-Helmholtz, theory of primary 



colour sensa- 

 tions, 1229 



,, ,, ,, as applied to 



colour blind- 

 ness, 1239, 

 1243 



,, ,, ,, of simultane- 



ous and suc- 

 cessive con- 

 trasts, 1267 



Zinn, zonnle of, 1168 



,, ,, passage of fluid by the, 1309 

 Zona pellucida or radiata, 1493 



,, spongiosa of cord, 865 

 Zone, ciliary, 1164 



,, peripheral of capillaries, 335 



,, Lissauer's, 875 

 Zymogens, 415, 419 



F. 



102 



