242 FACULTIES OF BIRDS. 



the first case will press her body downwards rather 

 than upwards ; while, as her evident intention is not 

 to rise above the ground, she forcibly expels the air 

 from her air-cells, as may be inferred from the 

 screaming always uttered on those occasions, and 

 caused, we have reason to believe, by the forcible 

 expulsion of the air. Her body is thus rendered 

 specifically heavier, and consequently resists the up- 

 ward impulse given by the downward motion of the 

 wings. The pheasant, on the other hand, instead of 

 expelling the air, takes a deep inspiration, increasing 

 the size of the body as much as possible, inflating at 

 the same time the wing-feathers, and bulging them 

 outwards without separating their tips from the sides. 

 While taking deep inspirations, he may be observed 

 also several times rising on tiptoe and puffing out 

 and balancing his body, to feel whether he has 

 thrown enough of air into the bones and feathers to 

 float him along. He then crouches back in order to 

 give additional force to his spring, and forthwith 

 leaps up into the air, at the same time rapidly raising 

 his wings from the sides, but keeping the individual 

 feathers close together like a folded fan, which he 

 takes care not to open till he begins to bring them 

 down. For this purpose he spreads them out to 

 their utmost extent, and then striking the air with all 

 his force, its resistance pushes him upwards, and he 

 bounds aloft towards his tree-perch, or wherever else 

 he wishes to go. The same series of motions, first 

 raising the folded wings, and then forcibly bringing 

 down the spread wings, must be incessantly re- 

 peated during the flight of every bird ; in the same 

 way as a swimmer, by pressing the water downwards 

 with his spread hands keeps himself afloat, and, by 

 directing the motion obliquely backwards, is thereby 

 pushed forwards. It may also be remarked, that the 

 swimmer raises his hands before renewing the stroke 



