856 



INDEX. 



PAGE 



Vertebral column of skate . 512 

 ,, ,, of snakes . 608 



,, theory of skull . 461 



Vertebrata . . . -453 

 ,, affinities of Annelids 



with . . . 456 

 ,, affinities of Nemer- 



teans with . 456 



,, ancestry of . -455 

 ,, development of . 457 

 ,, general characters 



of . 453 

 ,, ,, classifica- 



tion of 455 



,, gill-clefts of . . 570 

 ,, heart of . . 485 

 ,, and Invertebrata . 8 

 ,, nervous system of . 466 

 ,, notochord of . . 458 

 ,, segmental symme- 

 try of . 453 

 ,, structure of . . 457 

 Vesiculse seminales. See Re- 

 productive system. 

 VesiculatEe . . . .146 

 Vespertilio . . . .761 

 Vesperugo . . . .761 

 Vestigial structures . . 40 

 Vibrissse .... 684 

 Vicugna . . . -733 



Villi 29 



Visceral arches . . . 459 



,, clefts . . . 480 



., nerves . . .201 



Vitelline membrane of ovum 59, 657 



Vitreous humour . . . 477 



Viverra . . . -754 



Viviparous Fishes . . 541 



,, Insects . 334 



,, Lizards . . 605 



,, Vertebrates . . 495 



Voice of Birds . . . 653 



Vole 749 



Volvox . . . . 70, 95 

 Vorticella 93 



WALUHEIMIA 

 Walking-stick insect 



,, leaf 

 Wallace's line 



238 

 345 



345 

 802 



Walrus .... 

 Wasps .... 

 Water bears . 

 Water scorpion 



,, vascular system of 



,, Crinoid 



,, Holothurian 



,, Ophiuroid . 



,, sea-urchin . 



, , starfish 



Weasel .... 

 Web of Spiders 

 Whales 



Wheel animalcule . 

 Whelk .... 

 Whip scorpions 

 White matter o< brain . 



,, ,, of spinal cord 

 Wing of bat . 



,, of Birds 



,, of insect 



,, of pterodactyl 

 Wolf .... 

 Wolffian duct 

 Worms . . 10, II, 



XANTHARPYIA 



Xenarthra 



Xiphisternum 



Xiphosura 



Xylophaga 



YAPOCK 



Yellow cells . . 



Yolk .... 



,, sac 



,, ,, placenta . 



,, spherules (in Hydra) 



ZEBRA 



Zoantharia . 



Zona radiata of ovum 



Zoochlorelke . 



Zoo-geographical regions 



Zoonerythrin. 



Zoophytes 



Zootoca 



Zygsena 



Zygapophyses 



Zygomatic arch 



I'AGE 



756 



344 



358 

 . 344 



. 260 



. 256 



. 249 



253 



245 



755 



355 



743 

 . 233 

 . 400 



350 

 . 471 



. 472 



759 

 . 638 



325 

 . 624 



754 

 . 491 



169-238 



. 761 



727 



5 6 4 



358 

 . 408 



723 

 no 



59 



. 707 



. 708 

 . 144 



739 

 300 

 164 



493 

 no 



804 

 126 



133 



606 



547 

 675 



752 



i 5 8 ; 



