The Natural History of Selborne 247 



where they can be in no ways influenced by any defect of heat, or, 

 as one might suppose, failure of food. Are they regulated in their 

 motions with us by a defect 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 

 searches, but almost eludes our guesses. 1 



These hirundines never perch on trees or roofs, and so never con- 

 gregate 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 hippoboscte 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 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 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 pi ece 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. 



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



1 It is really the question of food-supply that regulates their movements. ED. 



