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an organization so favourable to flying, perform 

 that action. A bird, says Richerand, begins by 

 ascending into the air, either by rising at once 

 from the ground, or by allowing himself to fall 

 from a height. If, on the ground, and if his 

 wings are too large to be freely spread, he has 

 difficulty in rising. In that case he goes to an 

 elevated spot, and throws himself from it, that 

 he may have sufficient room to spread his wings, 

 and strike, in the air, the first stroke that is to 

 raise him. The wings expand horizontally, the 

 single bone which forms their upper and princi- 

 pal part, standing off from the body ; they then 

 ascend rapidly, and, as the air resists the sudden 

 effort which tends to depress it, the body of the 

 bird is elevated by a kind of elastic reaction, cor- 

 responding to the leap of man, and to the swim- 

 ming of fishes. The impulse being given, the 

 bird closes his wings and contracts his dimen- 

 sions as much as possible, that the impulse 

 may be almost entirely employed in raising his 

 body, and may not be counteracted by the resist- 

 ance of the air. This resistance of the air, but 

 particularly the weight of the bird, would soon 

 overcome the velocity which has been obtained, 

 and he would drop, if, by again striking the air, 

 he did not again rise. If the bird strike a second 

 time with his wings, before the impulse commu- 

 nicated by the first stroke be over, he rises rapidly, 

 but on the contrary, descends, if this motion be 

 delayed. Again, if he allow himself to fall only 

 to the height whence he began to rise, he may, 



