64 BOOK OF NATURE LAID OPEN. 



The structure of these creatures, as well as their 

 appetites, is 'however well adapted for the situations 

 in which they are severally placed, and they appear 

 to know well how to supply the defect of some of 

 their members by the use which they make of others. 



Of all animals that move on their legs, the Os- 

 trich is by far the swiftest ; and although the Ara- 

 bians train their fleetest horses for the chase, it is 

 not likely they would be successful in the pursuit of 

 this animal, were it not for his circling manner of 

 running. Nor is this surprising, when we consider 

 that this lofty mass of light materials is not only 

 carried forward by his long springing legs, but is 

 impelled along by his wings, which he keeps in con- 

 stant motion, and apparently serve the purpose of 

 oars. 



The Emu, or Ostrich of the new continent, is also 

 a remarkably swift runner, but its manner of assist- 

 ing its legs is somewhat different from the former ; 

 besides making use of something behind, like a heel, 

 to push it forward, this animal uses a kind of action 

 peculiar to itself, first lifting up one wing and keep- 

 ing it elevated for some time in form of a sail, then 

 letting it drop and elevating the other ; by this 

 means it moves along with such rapidity, that even 

 the Greyhound can seldom overtake it. The fa- 

 vourite climate of the Cassowary seems to begin 

 where that of the Ostrich terminates, in the old 

 world ; and although its wings are so very small^ 

 that being covered with the hair on the back they 

 are scarcely perceptible, it kicks up behind with the 



