BIRDS ON THE WING. 53 



that he is a dexterous wiiigster?) One winter day, 

 when the wind was blowing a gale from the west, 

 I saw one of these aliens tacking in the storm. 

 He wanted to move at right angles with the cur- 

 rent of the wind, and how did he go about it? He 

 lifted himself lightly into the air, thrusting his 

 head into the very teeth of the wind at an acute 

 angle with the current, and then darted swiftly 

 away, moving sidewise, in easy, undulatory flight, 

 veering verv little from the course he had marked 

 out for himself. 



Few birds are more agile on the wing than the 

 swifts and swallows. They spend a large part of 

 their time tilting in the air, catching insects as 

 they wheel on in their swift course. How many 

 miles do you suppose they fling behind them in a 

 single day? Doubtless you have often watched 

 the cliff swallows as they perform their feats of 

 scaling in the air. How gracefully they glide, now 

 sweeping down a sheer declivity, now mounting 

 upward in an almost vertical line, now poising a 

 moment as if resting on the wings of nothing, and 

 anon making another swift plunge that causes one's 

 head to swim ! The swifts move their wings in 

 short, quick strokes, while the strokes of the swal- 

 lows are longer and made more leisurely. 



