272 NATURAL HISTORY 



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 ap- 

 proaches their nests. They seem not to be of a sociable 

 turn, never with us congregating 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 seques- 

 tered 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 pecu- 

 liar 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 Lon- 

 don, frequenting the dirty pools in St. 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 scaflbld 

 holes of some old 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 dimi- 

 nutiveness of their size and in their colour, which is 



