EXPLANATIOX NIGHT 103 



of little sliai'[) barks like those lie gives at cats and 

 Woodchucks, and all tlie hair over his backbone ruffled 

 up ; but when I looked at him his eyes were shut 

 tight." 



^' ^lammals are of a good many sizes, and move about 

 in a great many different ways, — run and lope and 

 jump, — but they almost all have four legs, don't 

 tliey ? " asked Rap. 



"They are of all sizes, from a Mouse of a few inches 

 to the great Whales that measure seventy or eighty 

 feet in length, l)ut they are not by any means all pro- 

 vided with four legs. Afammals are often called 

 Quadrupeds, or four-footed animals, and the greater 

 number do have four feet ; but one has two feet, Avhile 

 others like the Whale have no feet. 



" The majority of Mammals live on the surface of 

 the earth, and tlieir limbs are formed for walking. 

 They never have more than two pairs of legs, and may 

 lack hind limbs ; but you will never see them with hind 

 legs and no fore limbs." 



'' There are lots of useful Mammals, too, besides all 

 the little nuisance ones, aren't there. Uncle Roy?" 

 asked Dodo. 



" Yes, surely ; Mammals are the most useful of 

 all animals. They supply us with meat, milk, hides, 

 wool, fur, horn, and ivory. The Whale gives oil, 

 whalebone, and spermaceti ; the hoofed Mammals — 

 horses, oxen, etc. — are draught animals. I want you 

 to look at your tree and I Avill show you the ladder I 

 have made to go with it. You remember the wa}' in 

 which the Bird Families all walked together in a pro- 

 cession, each wearing his Latin name, that the Wise 



