seen them nesting in the Borough, but even in the 

 Strand and Fleet Street ; but then it was obvious 

 from the dinginess of their aspect that their feath- 

 ers 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. Accord- 

 ingly, they make use of a placid easy motion in a 

 middle region of the air, seldom mounting to any 

 great height, and never sweeping long together over 

 the surface of the ground or vv^ater. 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 October the 21st, 

 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 villages on the 

 Thames, darkening the face of the sky as they fre- 

 quent the aits of that river, where they roost. They 

 retire, the bulk of them I mean, in vast flocks to- 

 gether about the beginning of October ; but have 

 appeared of late years in a considerable flight in this 



neighbourhood, for one day or two, as late as No- 



200 



