156 
NATURAL HISTORY OF SELBORNE. 
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, seldom 
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 
imder 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 twenty-first, 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 fre- 
quent the aits of that river, where they roost. They retire, the 
bulk of them I mean, in vast flocks together 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- 
vember the third and sixth, after they were supposed to have 
been gone for more than a fortnight. They therefore withdraw 
with us the latest of any species. Unless these birds are very 
short-lived indeed, or unless they do not return to the district 
where they are bred, they must undergo vast devastations some 
how, 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 breeding they 
are often greatly molested with fleas.* I am, &c. 
* In the wilder districts of Scotland, there are several localities where eave swallows build 
abundantly, and in large communities, ag^ainst the perpendicular or overhanging precipices of 
rocks, obviously their natural site for nidification. The young differ from their parents in being 
browner in their general tint, with less gloss on the upper feathers ; the tertiaries are tipped with 
white; the tail somewhat less forked; and the under parts are brownish about the breast, as in 
the bank-swallow. The adults moult before retiring to a warm region, but the young do not 
commence their change of plumage while in this country. The latter undergo a total moult 
during their absence, including the primary feathers of the wings and tail, as the latter is rather 
more forked when they return in spring, and the former a trifle longer. — Ed. 
