IND.KX. 



377 



Veins, influence of expiration on, i, 2(>? 

 inspiration, i, 206 



influence of gravitation in, i, 163 



parietal system of, ii, 283, et seq. 



pressure in, i, 162 



rhythmical action in, i, 162 



structure of, i, 136 



systemic, i, 102 



umbilical, ii, 270 



valves of, i, 137 



velocity of blood in, i, 165 



visceral system of, ii, 283, et seq. 

 Velocity of blood in arteries, i, 164 

 in capillaries, i, 165 

 in veins, i, 165 



of circulation, i, 163 



of nervous force, ii, 81 

 Venaportaa.i, 88,269 

 Venae hepatica? advehentes, ii, 283 



revehentes, ii, 284 

 Ventilation, i, 204 

 Ventricles of heart, i, 112 



capacity of, i, 107 



contraction of, i, 112 

 effect on blood-current in veins, i, 124 



dilatation of, i, 124 



force of, i, 124 



of larynx, office of, ii, 60 

 Ventriloquism, ii, 62, 194 

 Vermicular movement of intestines, i, 



289 



Vermiform process, i, 262 

 Vertebrae, development of, ii, 270 

 Vesicle, germinal, ii, 237 



Graafian, ii, 235 

 bursting of, ii, 240 



umbilical', ii, 254, 261 

 Vesicula germinativa, ii, 237 

 Vesiculae seminales, ii, 250 



functions of, ii, 250 



reflex movements of, ii, 103 



structure, ii, 250 

 Vestibule of the ear, ii, 182 

 Vestigial fold of Marshall, ii, 285 

 Vibrations, conveyance of to auditory 

 nerve, ii, 185, et seq. 



perception of, ii, 194 



of vocal cords, ii, 52 

 Vidian nerve, ii, 144 

 Villi inchorion,ii,265 



in placenta, ii, 268 

 Villi of intestines, i, 259 



action in digestion, i, 260 

 Visceral arches, development of, ii, 273 



connection with cranial nerves, ii, 274 



laniinse or plates, ii, 260 

 Vision, ii,196 



angle of, ii, 221 



at different distances, adaptation of eye 

 to, ii, 207, et seq. 



contrasted with touch, ii, 221 



corpora quadrigemina, the principal 

 nerve-centres of, ii, 114 



correction of aberration, ii, 213, et seq. 

 of inversion of image in, ii, 218 



Vision, defects of, ii, 211, et seq. 

 distinctness of, how secured, ii, 203, et 



seq. 



double, ii, 229 



duration of sensation in, ii, 216 

 estimation of the form of objects, ii, 222 

 of their direction, ii, 222 

 of their motion, ii, 222 

 of their size, ii, 221 

 field of, size of, ii, 220 

 focal distance of, ii, 206 

 impaired by lesion of fifth nerve, ii, 



140 



influence of attention on, ii, 223 

 modified by different parts of the ret- 

 ina, ii, 226 

 purple, ii, 218 

 in quadrupeds, ii, 230 

 single, with two eyes, ii, 231 

 Visual direction, ii, 222 

 Vital or respiratory capacity of chest, i, 



189 



Vital capillary force, i, 161 

 Vital force, ii", 321 

 Vitellin, ii, 329 

 Vitelline duct, ii, 261 

 membrane, ii, 237 

 spheres, ii, 253 

 - Vitreous humor, ii, 205 

 Vocal cords, ii, 52 

 action of in respiratory actions, i, 188, 



et xeq. 

 approximation of, effect on height of 



note, ii, 56 

 elastic tissue in, i, 33 

 longer in males than in females, ii, 57 

 position of, how modified, ii, 56 

 vibrations of, cause voice, ii, 51 

 Voice, ii, 50/57 

 of boys, ii, 58 

 compass of, ii, 57 

 conditions on which strength depends, 



ii, 58 

 Voice, human, produced by vibration of 



vocal cords, ii, 50, 55 

 in eunuchs, ii, 58 

 influence of age on, ii, 58 

 of arches of palate and uvula, ii, 59 

 of epiglottis, ii, 55 

 of sex, ii, 57 

 influence of ventricles of larynx, ii, 60 



of vocal cords, ii, 56 

 in male and female, ii, 57 



cause of different pitch, ii, 57 

 modulations of, ii, 57 

 natural and falsetto, ii, 58 

 peculiar characters of, ii, 57 

 varieties of, ii, 58 

 Vomiting, i, 251 

 action of stomach in, i, 251 

 nerve actions in, i, 252 

 voluntary and acquired, i, 252 

 Vowels and consonants, ii, 60 

 Vulvo- vaginal or Duverney's glands, ii, 

 239 



