BANK SWALLOW, 603 



insects with facility, nature, ever provident, may have be- 

 stowed upon it this property that it may also be better able to 

 elude the movements of its enemies, and thus be spared to 

 preserve the atmosphere, to a certain extent, in a state of 

 purity. These Swallows are not with us, as White says 

 they are at Selborne, " fera natura;" for they both fly in 

 companies and frequent for the most part places within a few 

 yards' distance of houses." 



" About the beginning of May 1838," Mr Durham Weir in- 

 forms me, "acolonyof Sand Martins arrivedatBalbardie Quarry, 

 in the neighbourhood of Bathgate, where they had reared their 

 young for seven successive years. On the 20th of the same 

 month, I saw them carrying straw and feathers into their 

 holes, of which there were about seventy. They were ducr in 

 a stratum of sand, about four or five feet below the surface 

 of the earth, resting upon a bed of gravel, about fifty feet from 

 the bottom of the sandstone rock, which is used in building. 

 To the face of this precipitous bank I have observed them 

 clinging with their sharp claws, and boring with their bills, 

 till they had loosened a portion of the sand, and tumbled it 

 down amongst the rubbish below. When they burrowed fur- 

 ther in, they seemed to scrape out with their feet what they 

 had detached by their bills. A number of their holes were 

 circular, whilst others were more irregular in their form, but 

 this might have been occasioned by the sand crumbling away. 

 On the 3d of July, upon the banks of the river Almond, near 

 the village of Livingstone, I examined several of their nests. 

 Some had ripe young ones in them, others only eggs. I found 

 that all the holes were funnel-shaped at the extremity, the 

 widest part being in the middle, and that they were of various 

 depths, some of them being eighteen inches, others two feet, 

 and a few three feet deep. 



" Of all our Swallows they seem to be the most social, nest- 

 ling in numerous communities, and often within a few inches 

 of each other. I have seen them flying in troops from a dozen 

 to forty, in pursuit of insects. During the pairing season the 

 males often fight most resolutely. I am acquainted with a 

 man who has again and again caught them, and separated 



