442 



INDEX. 



Vis'cus, Vis'cera, plural (Latin), intes- 

 tine^ bowels. 



Vitelline (Lat. vitellus, yolk), of, or 

 belonging to the yolk. 



Vitel'lus, or yolk of eggs, 444. 



Vit'reous humour (Lat. vitreus, 

 glassy), the humour of the eye on 

 which the retina or expansion of 

 the optic nerve is extended, 127. 



Vivip'arous (Lat. vivus, alive ;paric, 

 I bring forth), animals which 

 bring forth their young alive, 434. 



Vocal cords, 180. 



Voice, the, 177 184 ; speech con- 

 fined to man, 184. 



Voluntary (Lat. vofo, I will), under 

 control of the wilL 



Voluntary and involuntary motions, 

 211. 



WALKING, 293295. 



Warm-blooded animals, as birds, 



mammals, &c. 399. 

 Water, equalizing effects of large 



sheets of, 636. 



Water-tubes of aquatic animals, 403. 

 Whales, mode of swimming, 304, 307. 

 Worms, or Ver'mes, class of, xxii. 



YOLK of egg, 444. 



Young, development of the, 447 449. 



ZOOLOG'ICAL regions, chart of, ex- 

 plained, xii. 



Zool'ogy, its sphere and fundamental 

 principles, 1 29. 



Zo'ophytes (Gr. ^wov, animal, QVTOV, 

 a plant), the lowest primary divi- 

 sion of the animal kingdom, which 

 includes many animals that are 

 fixed to the ground and have the 

 form of plants, 68. 



BY W. CLOWES AND SONS, STAMFORD STREET 

 AND CHARING CROSS. 



