NATURAL HISTORY OF SELBORNE. 179 



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 can 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 jlat, 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 for- 

 ward ; besides, the least toe, which should be the back toe, 

 consists of one bone alone, and the other three only of two 

 apiece, — a construction most rare and peculiar, 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. 



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, 

 but do not venture, like the house-martin, into the close, 

 crowded part of the town. 



The Swedes have bestowed a very pertinent name on this 

 swallow, calling it " ring swala," from the perpetual rings 

 or circles that it takes round the scene of its nidification. 



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



