I<j4 THE NATURAL HISTORY [LETT. 



and so nearly correspondent in their general mode of life ! 1 For 

 while the swallow and the house-martin discover the greatest 

 address in raising and securely fixing crusts or shells of loam as 

 cunabula for their young, the bank-martin terebrates a round and 

 regular hole in the sand or earth, which is serpentine, horizontal, 

 and about two feet deep. At the inner end of this burrow 

 does this bird deposit, in a good degree of safety, her rude nest, 

 consisting of fine grasses and feathers, usually goose-feathers, 

 very inartificially laid together. 



Perseverance will accomplish anything: though at first one 

 would be disinclined to believe that this weak bird, with her 

 soft and tender bill and claws, should ever be able to bore the 

 stubborn sand-bank without entirely disabling herself; yet with 

 these feeble instruments have I seen a pair of them make great 

 despatch : and could remark how much they had scooped that 

 day by the fresh sand which ran down the bank, and was of a 

 different colour from that which lay loose and bleached in the 

 sun. 



In what space of time these little artists are able to mine and 

 finish these cavities I have never been able to discover, for rea- 

 sons given above ; but it would be a matter worthy of observa- 

 tion, where it falls in the way of any naturalist to make his 

 remarks. This I have often taken notice of, that several holes 

 of different depths are left unfinished at the end of summer. 

 To imagine that these beginnings were intentionally made in 

 order to be in the greater forwardness for next spring is allowing 

 perhaps too much foresight and rerumprudentia to a simple bird. 

 May not the cause of these Intcbrcc being left unfinished arise from 

 their meeting in those places with strata too harsh, hard, and solid 

 for their purpose, which they relinquish, and go to a fresh spot 

 that works more freely ? Or may they not in other places fall 

 in with a soil as much too loose and mouldering, liable to foun- 

 der, and threatening to overwhelm them and their labours ? 



1 " Each creature hatli a wisdom of its own ; 



The pigeons feed their tender offspring, crying, 

 When they are callow, but withdraw their food 

 When they are fledged, that they may teach them flying." 



HERUEHT. 



