456 



INDEX. 



Vaso-motor centre, relations of to other 



centres, 327 

 ,, fibres, constrictor, 310, 312 



course of, 317, 322, 



330 

 ,, ,, ,, loss of medulla in, 



317 

 ,, ,, ,, tonic action of,319 



323 



,, ,, ,, chief parts of body 



supplied by, 322 

 ,, dilator, 312 



,, course of, 318 



,, ,, ,, usually employed as 



part of reflex ac- 

 tion, 321 

 ,, ,, ,, retention of medulla 



in, 331 

 ,, functions of the central nervous 



system, 321 



,, nerves of veins, 333 

 Vegetable cell, storage of metabolic pro- 

 ducts in, 828 

 ,, diet, results of, 839 

 ,, ,, large amount required, 841 



Veins, structure of, 196 

 ,, minute, 197 

 ,, valves of, 197, 219 

 ,, their capacity as compared with 



arteries, 200 



blood-pressure in, 203, 207 

 ,, vaso-motor nerves of, 333 

 Velocity of nervous impulse, 75 

 ,, of muscular contraction, 87 

 ,, equal, of muscular current of action 



and nervous impulse, 124 

 ,, comparative, of arterial, venous and 



capillary circulation, 209220 

 ,, of blood-current, 263 

 ,, of pulse wave, 264 

 Venae stellatse of kidney, 645 

 Venous circulation, aids to, 219 

 pulse, 271, 613 

 ,, sinuses of brain, 1133 

 Ventilation, positive and negative of 



lung, 594 



Ventricle of heart of frog, action in heart- 

 beat, 282 



,, ,, ,, of tortoise, isolated, 

 spontaneous beat of, 

 285 

 Ventricles of heart, synchronism of their 



action, 229 



,, ,, ,, change of form of in car- 

 diac cycle, 232 

 ,, ,, ,, four stages of action of, 



246 



,, ,, ,, tonic contraction of, 304 



of brain, development of, 930 



Vermiform appendix, solitary follicles in 



the, 489 



Vertigo, causes of, 1015 

 Vesicles, cerebral, 929 

 optic, 1140 



Vesicles, otic, iv. 177 

 Vesiculse seminales, iv. 370 

 ,, ,, secretion of, iv. 370 

 ,, ,, their action in emission,iv.372 

 Vestibule of ear, iv. 176 



,, parts of, iv. 198 



,, ,, perilymph cavity of, iv. 200 



Vibrations of muscle sound, 140 



,, sonorous, longitudinal and trans- 

 versal, iv. 190 

 ,, ,, of the tympanic membrane, 



iv. 191 

 ,, ,, through the auditory ossicles, 



iv. 192 

 ,, ,, through the bones of the skull, 



iv. 193 



,, of sound and light compared,iv.225 

 interference of, iv. 229 

 Vierordt, his ha3matachometer, 222 

 Vieussens, annulus of, 299 

 Villi, the, of small intestine, 445 



,, columnar epithelium of, 445, 516 

 ,, goblet cells of, 446 

 ,, structure of, 447 

 ,, pumping action of. 519 

 ,, of chorion, feetal, iv. 377 

 Vision, 1070 



binocular, 1071, iv. 134154 



, , , , its action in j udging of distan ce, 



iv. 151 



,, ,, ,, ,, of solidity,iv.l62 



,, ,, mechanism of, 1071 

 ,, central apparatus for, 1077 

 ,, imperfections of, 1078 

 ,, affected by injury to cortex, 1081 

 ,, dioptric mechanisms of, iv. 1, 6 

 ,, astigmatism, iv. 48 

 ,, spherical aberration, iv. 48 

 ,, chromatic aberration, iv. 50 

 ,, entoptic phenomena, iv. 51 

 distinct, limits of, iv. 80 

 ,, trichromic nature of, iv. 91, 98 

 ,, colour, Young-Helmholtz' theory 



of, iv. 91, 129 



Hering's theory of, iv. 93, 129 

 - field of, 1071, iv. 123, 135 

 ,, corresponding or identical points, 



iv. 137 

 ,, struggle of the two fields of, iv. 



155, 164 



Visual areas in fovea centralis, iv. 81 

 ,, axis, iv. 134 



centres, lower and higher, 1084 

 ,, impulses, development of, iv. 110 

 ,, origin of, iv. 114 



,, perceptions and judgments, iv. 



155164 



psy chical processes in, i v.l 58 



,, plane, iv. 135 

 ,, purple, iv. 116 

 sensations, 1070 1085 

 ,, probable mode of de- 



velopment of, 1 083 

 ,, fusion of, iv. 76, 80 



