144 THE NATURAL HISTORY 



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 parti- 

 cular 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 White -Chapel. 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 old or new deserted building. They dip and wash 

 as they fly sometimes, like the house -mart in 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 Montagna. 



