NATURAL HISTORY OF SELBORNE. 185 



are dispossessed of their breeding holes by the house-sparrow, 

 which is on the same account a fell adversary to house-martins. 



These hirundines 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 congre- 

 gating with their congeners 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 hirundines 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 genus of insects 

 affords the principal food of each respective species of swallow. 



Notwithstanding what has been advanced above, some few 

 sand-martins, I see, haunt the skirts of London, frequenting the 

 dirty pools in Saint George's Fields, and about Whitechapel. The 

 question is where these build, since there are no banks or bold 

 shores in that neighbourhood ; perhaps they nestle in the scaffold 

 holes of some ojd or new deserted building. They dip and wash 

 as they fly sometimes, like the house-martin and swallow. 



Sand-martins differ from their congeners in the diminutiveness of 

 their size, and in their colour, which is what is usually called a 

 mouse-colour. Near Valencia, in Spain, they are taken, says 

 Willughby, and sold in the markets for the table ; and are called 

 by the country people, probably from their desultory jerking 

 manner of flight, Papilion de Montagua* 



