NATURAL HISTORY OF SELBORNE 133 



and Fleet Street ; but then it was obvious from the dinginess 

 of their aspect that their feathers partook of the filth of that 

 sooty atmosphere. Martins are by far the least agile of the 

 four species ; their wings and tails are short, and therefore 

 they are not capable of such surprising turns and quick and 

 glancing evolutions as the swallow. Accordingly they make 

 use of a placid easy motion in a middle region of the air, sel- 

 dom mounting to any great height, and never sweeping long 

 together over the surface of the ground or water. They do 

 not wander far for food, but affect sheltered districts, over 

 some lake, or under some hanging wood, or in some hollow 

 vale, especially in windy weather. They breed the latest of 

 all the swallow kind : in 1772 they had nestlings on to Octo- 

 ber 2 ist, and are never without unfledged young as late as 

 Michaelmas. 



As the summer declines the congregating flocks increase in 

 numbers daily by the constant accession of the second broods ; 

 till at last they swarm in myriads upon myriads round the vil- 

 lages on the Thames, darkening the face of the sky as they 

 frequent the aits of that river, where they roost. They retire, 

 the bulk of them I mean, in vast flocks together about the begin- 

 ning of October ; but have appeared of late years in a consid- 

 erable flight in this neighborhood, for one day or two, as late 

 as November 3rd and 6th, after they were supposed to have 

 been gone for more than a fortnight. They therefore with- 

 draw with us the latest of any species. Unless these birds 

 are very short-lived indeed, or unless they do not return to 

 the districts where they are bred, they must undergo vast 

 devastations somehow, and somewhere; for the birds that 

 return yearly bear no manner of proportion to the birds that 

 retire. 



House-martins are distinguished from their congeners by 

 having their legs covered with soft downy feathers down to 

 their toes. They are no songsters ; but twitter in a pretty 

 inward soft manner in their nests. During the time of breed- 

 ing they are often greatly molested with fleas. 



I am, etc. 



