BIRDS' NESTS. 65 



deserted habitation of a water-rat or sand- 

 martin. It usually lays six or seven eggs, 

 which are nearly orbicular, of a uniform white 

 tinged with the most delicate green, 



SWIFT. Cypselus Apus. 



NATURALISTS have given to this bird the 

 specific name Apus (footless) ; and, indeed, its 

 legs are so short, that were it to alight on the 

 ground, it would be totally unable to raise 

 itself so as to take flight again. Consequently, 

 it has little power of collecting materials for 

 building. Some ornithologists state that it 

 gathers the materials of its nest while on the 

 wing ; others, with more show of reason, state 

 that it universally occupies the deserted nest 

 of a house-sparrow, selecting one which has 

 been placed in the wall of a church, or some 

 other elevated building. When it has once 

 established itself, it usually retains its habi- 

 tation for many years, which, as it is never 



