154 The Natural History 



taken by hand : but whether the dams ever feed them on 

 the wing, as swallows and house- martins do, we have 

 never yet been able to determine ; nor do we know 

 whether they pursue and attack birds of prey. 



When they happen to breed near hedges and enclos- 

 ures, they are dispossessed of their breeding holes by the 

 house-sparrow, which is on the same account a fell 

 adversary to house-martins. 



These hirtituiines are no songsters, but rather mute, 

 making only a little harsh noise when a person 

 approaches their nests. They seem not to be of a 

 sociable turn, never with us congregating with their con- 

 geners in the autumn. Undoubtedly they breed a 

 second time, like the house-martin and swallow ; and 

 withdraw about Michaelmas. 



Though in some particular districts they may happen 

 to abound, yet in the whole, in the south of England at 

 least, is this much the rarest species. For there are few 

 towns or large villages but what abound with house- 

 martins ; few churches, towers, or steeples, but what are 

 haunted by some swifts ; scarce a hamlet or single 

 cottage-chimney that has not its swallow ; while the bank- 

 martins, scattered here and there, live a sequestered life 

 among some abrupt sand-hills, and in the banks of some 

 few rivers. 



These birds have a peculiar manner of flying ; flitting 

 about with odd jerks, and vacillations, not unlike the 

 motions of a butterfly. Doubtless the flight of all 

 hirimdines is influenced by and adapted to, the peculiar 

 sort of insects which furnish their food. Hence it would 

 be worth inquiry to examine what particular group of 

 insects affords the principal food of each respective species 

 of swalknv. 



Notwithstanding what has been advanced above, some 

 few sand-martins, I see, haunt the skirts of London, fre- 

 quenting the dirty pools in Saint George's-Fields, and 

 about White-Chapel. The question is where these build, 

 since there are no banks or bold shores in that neigh- 

 bourhood : perhaps they nestle in the scafibld-holes of 

 some old or new deserted building. They dip and wash 



