1G8 NATURAL HISTORY 



It is curious to observe with what different degrees of 

 architectonic skill Providence has endowed birds of the same 

 genus, and so nearly correspondent in their general mode of 

 life I 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 tere- 

 brates 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 to- 

 gether. 



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 dispatch : 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 reasons given above ; but it would be a matter worthy of 

 observation, 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 a.re left unfinished at the end 

 of summer. To imagine that these beginnings were inten- 

 tionally made in order to be in the greater forwardness for 

 next spring, is allowing perhaps too much foresight and rerum 

 prudentia to a simple bird. May not the cause of these 

 latebrce being left unfinished arise from their meeting in those 

 places with strata too harsh, hard, and solid, for their pur- 

 pose, 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 flounder, 

 and threatening to overwhelm them and their labours ? 



One thing is remarkable that, after some years, the old 



