604 



INDEX. 



V. 



Valves of heart, 272, 273; of veins, 279. 



Vascular area, 758. 



Vegetative repetition of parts, 2. 



Veins, 246 ; structure of, 248 ; pressure 

 of blood in, 249; arrangement of, 250, 

 266 ; flow of blood through, 277, 278 ; 

 valves in, 279. 



Vena cava, 266. 



Venaportae, 267, 366. 



Ventilation, importance of, 336, 337. 



Ventricles of brain, 458. 



of heart, 257; action of, 270. 



Ventriloquism, 525. 



Vertebrae, structure of, 71, 628; classifi- 

 cation of, 626 ; number of, 627 ; con- 

 nexion of, in Reptiles and Fishes, 

 629 ; in Man, 630; in Birds, 630. 



Vertebral column, 70, 71, 626632 ; first 

 development of, 757. 



VERTEBRATA, general characters of, 70 

 76; nervous system of, 449 452; 

 skeleton of, 599 ; gemmation in, 729 ; 

 embryonic development of, 757 762. 



Vessels, origin of, 393. 



Vestibule of ear, 518, 521. 



Vibrations, sonorous, 510 512; pitch 

 determined by number of, 523, 682. 



Villi of mucous membrane. 41 ; absorp- 

 tion performed through, 41, 217. 



Vision, dependent on light, 526, 542 ; 

 adaptation of eye to distinct, 543 553 ; 

 influence of attention on, 555 ; infe- 

 rences drawn from, 556 566 ; duration 

 of impressions, 567 ; distinction of 

 colours by, 568 570; erect, though 

 picture inverted, 558 ; single, with two 

 eyes; 559; double, 559. 



Vitality, independent, of parts of organ- 

 ism, 65. 



Vitreous humour, 536. 



Vocal cords, 681. 



Voice, confined to Vertebrata, 680 ; how 

 produced in larynx, 682; differences in 

 pitch and quality of, 683, 684. 



Voltaic electricity, discovery of, 583, 584. 



Voluntary movements, 589, 590. 

 Vorticella, reproduction of, 725. 

 Vowel sounds, 689, 690. 



Vulture, skeleton of, 668. 



W. 



Walking, act of, 657. 



Warm-blooded animals, 407409. 



Wasps, nest of, 711. 



Waste of the system, 160, 307, 345. 



Water, passed off" by kidneys, 369 ; ex- 

 haled from lungs, 343, 344 ; from skin, 

 370374. 



Water-Newt, 87. 



Wax formed from sugar only, 155. 



Webs of Spiders, 698. 



Whale, mouth of, 185; peculiar arterial 

 distribution in, 265; sensibility of 

 surface in, 491; blow-holes of, 509; 

 propulsion of, in water, 665, 666. 



Whalebone, 185. 



Wheel-animalcules, (see Rotifer a}. ' 



White fibrous tissue, 2329. 



White of egg, 14, 755. 



Wings, of Birds, 78, 668 ; of Bat, 669 ; 

 of Pterodactylus, 669; of Insects, 670; 

 action of, 667 672. 



Winter eggs of Hydra and Rotifera, 735. 



Wounds, healing of, 391 393; of ar- 

 teries, treatment of, 277. 



Wren, intelligence of, 717. 



X. 



Xylocopa, nest of, 703. 



Y. 



Yawning, 341. 



Yellow Fibrous tissue, 2329. 



Yellow spot of retina, 554. 



Yolk of egg, 733, 736, 754. 



Yolk-bag, 733, 754. 



Young animals, heat of, 408, 409. 



Z. 



Zoea, larva of Crab, 101. 



Zoophytes, 117, 121; tissues of, 64, 577; 

 circulation in, 296; gemmiparous pro- 

 duction of, 726; development of Me- 

 dusae from, 738, 740; generation of, 

 738, 739. 



THE END. 



I. CLAY, PRINTER, BREAD STREET JlILL. 



