168 NATURAL HISTORY OF SELBORNE. 
This species feeds much on little Coleoptera, as well as on gnats 
and flies ; and often settles on dug ground, or paths, for gravels to 
grind and digest its food. Before they depart, for some weeks, to 
a bird, they forsake houses and chimneys, and roost in trees; and 
usually withdraw about the beginning of October, though some 
few stragglers may appear on at times till the first week in 
November. 
Some few pairs haunt the new and open streets of London next 
the fields, but do not enter, like the house-martin, the close and 
crowded parts of the city. 
Both male and female are distinguished from their congeners by 
the length and forkedness of their tails. They are undoubtedly the 
most nimble of all the species: and when the male pursues the 
female in amorous chase, they then go beyond their usual speed, 
and exert a rapidity almost too quick for the eye to follow. 
After this circumstantial detail of the life and discerning oropy7) 
of the swallow, I shall add, for your further amusement, an anecdote 
or two not much in favour of her sagacity :— 
A certain swallow built for two years together on the handles of 
a pair of garden-shears that were stuck up against the boards in 
an out-house, and therefore must have her nest spoiled whenever 
that implement was wanted; and, what is stranger still, another 
bird of the same species built its nest on the wings and body of an 
owl that happened by accident to hang dead and dry from the 
rafter of a barn. This owl, with the nest on its wings, and with 
eggs in the nest, was brought as a curiosity worthy the most elegant 
private museum in Great Britain. The owner, struck with the 
oddity of the sight, furnished the bringer with a large shell, or 
conch, desiring him to fix it just where the owl hung : the person 
did as he was ordered, and the following year a pair, probably 
the same pair, built their nest in the conch, and laid their eggs. 
The owl and the conch make a strange grotesque appearance, 
and are not the least curious specimens in that wonderful collection 
of art and nature.* 
Thus is instinct in animals, taken the least out of its way, an 
undistinguishing, limited faculty, and blind to every circumstance 
that does not immediately respect self-preservation, or lead at once 
to the propagation or support of their species. 
I am, with all respect, &c. &c. 
* Sir Ashton Lever’s ‘‘ Muszeum.”’ 
