THE YELLOW WAGTAIL. 



at every pause require muscular action to set them 

 in progress anew, which, for any length of time, 

 could hardly be continued. It is probable that 

 their migrations are not very remote. The mode 

 of life assigned to these creatures requires great 

 activity of body ; for living solely upon insects and 

 winged animals, they are constantly capturing or 

 pursuing ; and their length of tail, which is per- 

 petually in motion, seems to aid and balance the 

 operations of the body. In the evening, when the 

 winged creatures are at rest, or, from the state of 

 the atmosphere, in repose, the wagtail resorts to 

 the pastures, feeding under the very bodies and 

 noses of the cattle, who now become the starters of 

 his game, which, moving from the animal, are cap- 

 tured by the bird. Being drowsy, and settling 

 almost as soon as disturbed, their prey would 

 escape, was the wagtail less nimble in his actions 

 for he does not appear to perceive the insect, except 

 when it moves. How differently formed is this 

 bird and the grey fly-catcher ! Though both are 

 solely insectivorous, yet they secure their prey by 

 very distinct means, the latter seldom capturing on 

 the ground or using his legs in pursuit ; the other 

 uses actively his slender legs and extended wings 

 to aid him. The swallow race, again, feed unlike 

 them both, and haunting the pool, the stream, the 

 mead, or the higher regions of the air, which his 

 fraternity possess as a peculiar domain, satisfy their 

 wants in peace, without collision or contention for 

 the object. 



