42 Allen's naturalist's library. 



June. Many succumb from cold and subsequent starvation, 

 from arriving too early, before the frosts have quite left us. 



As a rule the Swifts are most active towards the evening, 

 when they fly about in parties, dashing round the houses or 

 towers in which their nests are placed, screaming vociferously 

 in concert. Their food consists entirely of insects, which are 

 seized upon the wing. Nevertheless, at certain times, the 

 Swift may be seen hawking over the low ground, over a river, 

 or high in the air, even in the brightest sunshine, so that it is 

 evident that the daylight does not deter it from issuing forth 

 from its recesses, though it is undoubtedly in the twilight that 

 the bird is most active. 



The short legs of the Swift incapacitate it from walking on 

 the ground, and its long wings are obviously in the way ; but it 

 is a mistake to suppose that the bird can never rise from the 

 earth, as the contrary has been proved. It is, however, never 

 seen to settle voluntarily on the ground for the purpose of col- 

 lecting material for its nest, as can always be observed in the 

 case of the Swallows and the Martins. From the situations 

 in which it builds its nest or in which it roosts, it can always 

 shuffle to the openings and launch itself into the air. 



Nest. — A rough structure of straws and like material, mixed 

 with a few feathers and wool, and cemented together by the 

 saliva of the bird. It is sometimes placed in the crevice of a 

 cliff or building, or at the protected base of a spout, but is 

 more often placed under the roof of some building. 



Eggs. — Pure white, of an elongated oval shape. Generally 

 two in number, often three, and more rarely four, the texture 

 of the shell being always more rough than in the eggs of the 

 Swallows. Axis, 0*95-1 '05 ; diam., o'65-o7. 



THE SHORT-TAILED SWIFTS. SUB-FAMILY 

 CH.ETURIN^. 



This Sub-family contains a number of species, mostly tropi- 

 cal in their habitat. They have the toes with the usual four 

 joints, and the tarsi bare of feathers. The tarsi are long, 

 equalling the length of the middle toe, but the tail is very 



