INDEX OF SUBJECTS. 



1083 



Viability, early, of foetus, 913; relative, of two 

 Sexes, 967 



Yilli, intestinal, structure of, 61, 187 ; of 

 stomach, 154 



Vision, ganglia of, 650; nerves of, 652, 753 ; 

 Sense of, 744, 780 ; optical conditions of, 744- 

 747 ; defects in, 745 ; accommodation of, for 

 varying distances of objects, 748 ; nervous 

 apparatus of, 753-757 ; limits of, 757 ; use of 

 in combination with touch, 761 ; erect, cause 

 of, 762, 763 ; single, conditions of, 762 ; ap- 

 preciation of solid forms by, 764 ; of dis- 

 tances, 767 ; of size, 768 ; conversions of 

 relief, 770; persistence of impressions, 771 ; 

 complementary colors, 773; colored shadows, 

 773 ; acuteness of perception for colors, 776 ; 

 rapidity of perception, 774 ; want of power 

 to distinguish colors, 775 ; irradiation of im- 

 pressions, 775 ; vanishing of imnges, 776 ; 

 perception of laterally situated objects by, 

 776 ; imperfect perceptivity of optic disk, 

 777; electrical current induced by light, 

 777: phosphenes, 777; representations of 

 vessels of retina itself, 778 ; improvement of, 

 by attention, 779 ; importance of. in guiding 

 movement, 668 ; appreciation of varying 

 amounts of illumination by, 779 



Vital Economy, balance of, 421,440; ordi- 

 nary diet, 421 ; in inanition, 425 ; with pure 

 meat diet, 428 ; with meat and fat, 429 ; 

 with sugar and meat, 429 ; differences be- 

 tween Carnivora and Herbivora, in respect 

 to, 429 ; changes undergone by albumen in 

 maintaining, 81, 430; changes undergone by 

 fat in maintaining, 68 ; changes undergone 

 by sugar and starch in maintaining, 93, 434 ; 

 application of inorganic constituents of the 

 food to maintenance of, 434 ; work done in j 

 and by the body, 434 ; substitution of new 

 tissue for old in, 437 ; necessity of due sup- 

 ply of nervous power for maintenance of, 440 



Vitelline Duct, 928, 933. 



Vitelline Vessels, 933 



Vitellus, 925 ; its segmentation, 925, 931 



Voice, ordinary, mode of production, 853; 

 falsetto, 854 



Volition, fixation of attention by, in states of 

 Dreaming nnd Somnambulism, 716-718 



Volitional Actions, their source in the Cere- 

 brum, 706 



'Voluntary Movements, their dependence on 

 guiding sensations, 666, 667; performed by 



instrumentality of Sensori-Motor apparatus, 

 669 ; not in themselves distinguishable from 

 involuntary movements, 829 ; but result 

 from an impulse originating in Cerebrum, 

 706 



Vomiting, act of, 135 



Vowel sounds, 856 ; discrimination of, 858 



Walking, movements executed in, 831 



Water, the natural drink of Man, 116; effects 

 of drinking large quantities of, 116 ; effects 

 of impurity of, 116 ; effects of deprivation of, 

 123; normal proportion of, in Bkod, 253; 

 alterations in, 257 ; transudation of, by Kid- 

 ney, 498 



Water-dressing of wounds, 451 



Weight, appreciation of, 729, 730 



White Corpuscles, 241 ; see Blood, Colorless 

 Corpuscles 



Wolffian bodies, 948 



Woorara poison, influence of, on secretion of 

 Saliva, 151; action of, on Heart, 315, 316 

 note; action of, on Animal heat, 547; effect 

 of, on motor nerves, 821 



Xanthin, 92 



Yawning, act of, 382 ; consensual suggestion of, 



382 

 Yellow Fever, elevation of temperature after 



death from, 535; continuance of capillary 



circulation in, 348 ; immunity of Negroes 



from, 997 note. 



Yellow Spot of Retina, 754, 756, 776 

 Yolk of Egg, of fowl, structure of, 925 ; of fish, 



rotation of, 931 

 Youth, characteristics of, 1025 



Zo-amyline, 484 



Zona pellucida, 931 



Zymogen, 170 



Zymotic poisons, 285; predisposition to. in 

 consequence of state of blood, 286-289; 

 from bad air, 286; from putrescent food, 

 115; from putrescent water, 116 ; from alco- 

 holic liquors, 118; from starvation, 124; 

 from deficiency of respiration, 408-41 1 ; ten- 

 dency of the system to eliminate, 291 



