THE NATURAL HISTORY OF SELBORNE. |° 157 
called a mouse color. Near Valencia, in Spain, they are taken, 
says Willughby, and sold in the markets for the table; and 
are called by the country people, probably from their desultory 
jerking manner of flight, papz/on di montagna. 
LETTER XXI. 
SELBORNE, Seft. 28th, 1774. 
As the swift or black-martin is the largest of the British 
Hirundines, so it is undoubtedly the latest comer. For I re- 
member but one instance of its appearing before the last week 
in April: and in some of our late frosty, harsh springs, it has 
not been seen till the beginning of May. This species usually 
arrives in pairs. 
The swift, like the sand-martin, is very defective in archi- 
tecture, making no crust, or shell, for its nest: but forming it 
of dry grasses and feathers, very rudely and inartificially put 
together. With all my attention to these birds, I have never 
been able once to discover one in the act of collecting or 
carrying in materials; so that I have suspected (since their 
nests are exactly the same) that they sometimes usurp upon 
the house-sparrows, and expel them, as sparrows do the house 
and sand martins ; well remembering that I have seen them 
squabbling together at the entrance of their holes, and the 
sparrows up in arms, and much disconcerted at these in- 
truders. And yet I am assured, by a nice observer in such 
matters, that they do collect feathers for their nests in 
Andalusia, and that he has shot them with such materials in 
their mouths. 
Swifts, like sand-martins, carry on the business of nidification 
i quite in the dark, in crannies of castles, and towers, and 
steeples, and upon the tops of the walls of churches under the 
