214 On the Ornithology of Wilts [Ilirundinidce]. 



only do we welcome them as heralds of spring and harbingers oil 

 sunshine ; in addition to this, all their movements are so graceful,! 

 they are so essentially birds of the air, seldom touching the earth, 

 but careering all day long under the bright blue sky and through 

 the lofty pathways of the air, that they engage our particular 

 admiration and interest : if we stand still to watch one of these 

 birds in its course, see with what arrowy speed it darts over our 

 gardens, sweeps round our houses or skims over the pool : now it 

 will wheel and sport high up in the air, hurrying here and there 

 on the lightest wing in the gladness of its heart ; anon it will float 

 without effort in the vast expanse, as much at home and at ease as 

 other birds when perched on a tree or motionless on the ground : 

 and for this aerial life how admirably their structure is adapted : 

 observe the shape of the body, how full the forepart, how gradually 

 tapering towards the tail, which is exactly the principle on which 

 the fastest sailing ships are constructed : then see the plumage, 

 how firmly compacted, how little liable to be ruffled by the breezes 

 in a long and rapid flight ; mark the wings stretching out like 

 oars of vast length, and moved by muscles of extraordinary power : 

 note the long forked tail, supplying a never failing rudder to guide 

 the bird through those numerous windings in which it delights. 

 Other characteristics of this family, in addition to those belonging 

 to the whole tribe, are, very short beak, very broad at the base 

 and slightly bent ; head quite flat, and neck scarcely visible : their 

 note is rather a continued twitter than a song, though some of the 

 species will scream in a high and wild key, and others have a not 

 unpleasing though monotonous and very gentle melodious warble. 

 All the four species of this family with which we are acquainted 

 are summer visitants, leaving us in the autumn : it used to be 

 asserted by older naturalists, before the habits of birds had been so 

 closely observed, as of later years, that the Hir undines did not leave 

 this country in the winter, but retired to caves or holes, and there 

 remained dormant, like the bats and dormice : others maintained 

 the wilder theory that they plunged into the beds of rivers and 

 lakes, and there amidst the sedge and mud and reeds at the bottom, 

 slumbered away the dreary months of ice and snow, till the genial 



