SWIFTS. 195 



by a failure of food, or by a propensity to moulting, or by 

 a disposition to rest, after so rapid a life, or by what ? This 

 is one of those incidents in natural history that not only 

 baffles our researches, but almost eludes our guesses ! 



These hirundines never perch on trees or roofs, and so 

 never congregate with their congeners. They are fearless 

 while haunting their nesting places, and are not to be scared 

 with a gun, and are often beaten down with poles and cudgels 

 as they stoop to go under the eaves. Swifts are much 

 infested with those pests to the genus, called Jiippoloscce 

 hirundinis, and often wriggle and scratch themselves, in 

 their flight, to get rid of that clinging annoyance. 



Swifts are no songsters, and have only one harsh screaming 

 note ; yet there are ears to which it is not displeasing, from 

 an agreeable association of ideas, since that note never occurs 

 but in the most lovely summer weather. 



They never settle on the ground but through accident, 

 and when down can hardly rise, on account of the shortness 

 of their legs and the length of their wings : neither can they 

 walk, but only crawl ; but they have a strong grasp with 

 their feet, by which they cling to walls. Their bodies being 

 flat, they can enter a very narrow crevice ; and where they 

 cannot pass on their bellies, they will turn up edgewise. 



The particular formation of the foot discriminates the 

 swift from all the British hirundines, and, indeed, from all 

 other known birds, the hirundo melba, or great white-bellied 

 swift of Gibraltar excepted ; for it is so disposed as to carry 

 " omnes quatuor digitos anticos" all its four toes forward: 

 besides, the least toe, which should be the back toe, consists 

 of one bone alone, and the other three only of two a-piece, 

 a construction most rare and particular, but nicely adapted 

 to the purposes in which their feet are employed. This, and 

 some peculiarities attending the nostrils and under mandible, 

 have induced a discerning naturalist * to suppose that this 

 species might constitute a genus per se.-f 



In London, a party of swifts frequents the Tower, playing 

 and feeding over the river just below the bridge; others 

 haunt some of the churches of the Borough next the fields, 



* John Antony Scopoli, of Carniola, M.D. 



f The genus Cypselus of Illiger is now generally adopted for this group. 

 It is also the Apus of Belon. W. J. 



o2 



