100 



Order II 



and presumably in origin, becoming similar to one 

 another for all practical purposes. Apart from acci- 

 dental visitors, we have only in Britain one member 

 of the family, the black Swift or Deviling {Micropus 

 apus), which arrives a little later than the Swallows, 

 charms us by its aerial evolutions, startles us by its 

 piercing screams, and disappears very regularly by 

 September. It is peculiarly a denizen of the air, which 



Swift on nest 



rises from the ground with difficulty, and, having aU 

 its toes pointing forward, can hardly be said to perch. 

 The food consists of insects taken on the wing, as the 

 birds circle widely in the air, singly or in small parties ; 

 the flight is most characteristic, a number of quick 

 vibrations of the wings being followed by periods of 

 inactivity, when the bird ghdes with motionless wings 

 held in the shape of a bow. Swifts generally breed 

 in small colonies under the eaves of houses, but they 

 also make use of crevices in cliffs and quarries, as well 



