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CHAPTER V. 



Flight. Muscular power of Wings. Peculiarity of, in different 

 Birds. Adapted to various Habits. Rapidity of Motion and 

 Kate of, how calculated. Long continuance of Flight ac- 

 counted for. Migration, causes of. Tendency of most Birds 

 to wander at particular times. Why seldom seen in the act of 

 migrating. Instinctive power of finding their way. 



HAYING described the light and airy frame-work of birds 

 intended to pass more or less of their time in the air ; 

 and having shown how beautifully, in every particular, an 

 all-wise Creator has fitted them for such a life, we are natu- 

 rally led to follow them in their flight, and see how they are 

 still further prepared to turn their lightness of form to the 

 greatest advantage ; and, in pursuing this inquiry, the more 

 shall we be constrained to acknowledge, that "wondrous 

 are the works of God, and that in wisdom he hath made 

 them all, giving unto the Stork in the heaven to know 

 her appointed time, and the Turtle, and the Crane, and the 

 Swallow, to observe the seasons for their coming." No human 

 ingenuity or skill could ever have devised so perfect an 

 instrument as a bird's wing for its intended purpose; so 

 light, and yet so powerful ; so spacious when spread out, and 

 yet so compact, and gathered into so small a compass when 

 not wanted. 



We may form some idea of the extraordinary strength of 

 a bird, from knowing that the great muscle, which chiefly 

 regulates the movements of its wing, weighs more than all 

 the other muscles of its body put together, constituting not 

 less than one-sixth part of the weight of the whole body ; 

 whereas, those of the human body are not one-hundredth 

 part as large in proportion. 



Some birds have to seek their food on the wing, con- 

 sisting of such very small insects, that many hundreds must 



