190 MARVELS OP THE ANIMAL WORLD 



other animals that can progress upon their hind 

 legs alone. They do not walk in that manner, 

 however, but hop along, the two hind legs being 

 moved simultaneously and not alternately. When 

 feeding they go on aU fours. The larger species 

 of kangaroos are able to cover a distance of almost 

 thirty feet in a single leap ; and the jumping-hare 

 or springhaas, an animal about the size of an ordinary 

 hare, is able to take a jump of equal length when 

 hard pressed. As a rule, however, the latter crea- 

 ture does not spring forward for a greater distance 

 than nine feet in a single bound. 



One usually regards the tail of an animal as a 

 more or less ornamental appendage that is of little 

 use to its owner except as a fly-whisk, but such 

 is not always the case. A dog, for instance, when 

 running, will utilise that member as an aid for 

 turning rapidly ; and a cat, when walking along 

 the top of a narrow object such as a garden fence, 

 wiU employ its tail as a kind of balancing pole by 

 switching it first to the one side and then to the 

 other as occasion arises. Then, again, some crea- 

 tures possess a prehensile tail which serves as a 

 fifth limb, the capuchin monkeys, the spider 

 monkeys, the howler monkeys, the woolly monkeys, 

 some of the tree-porcupines, the tamandua and 

 the two-toed ant-eaters, many of the opossums and 

 phalangers, as well as the cuscuses all being thus 

 endowed. Sometimes the extremity of that member 

 is devoid of a hairy covering upon the under sur- 

 face, thus rendering it far more sensitive as a 

 graSiping organ than would be the case if it were 



