THE SWIFT. 771 
dines twice ; the latter, which lay from four to six eggs, increase at 
an average five times as fast as the former. 
But in nothing are swifts more singular than in their early retreat. 
They retire, as to the main body of them, by the tenth of August, and 
sometimes a few days sooner ; and every straggler invariably with- 
draws by the tw'entieth, though their congeners all of them stay till 
the beginning of October, many through all that month, and some 
occasionally to the beginning of November. This early retreat is 
mysterious and wonderful, since that time is often the sweetest season 
in the year. But, what is more extraordinary, they begin to retire 
still earlier in the most southerly parts of Andalusia, where they can 
be no ways influenced by any defect of heat, or, as one might suppose, 
defect of food. Are they regulated in their motions with us by a 
defect of food, or by a propensity to moulting, or by a disposition to 
rest after so rapid a flight, or by what? This is one of those incidents 
in natural history which not only baflle our researches, but almost 
eludes our guesses !” Swifts never perch on trees or roofs, and so 
never congregate with their congeners. They are fearless while 
haunting their nesting places, are not to be frightened away with a 
gun, and are often beaten down with poles and cudgels as they stoop 
to go under the eaves. Mr. White informs us, that having untiled 
part of a roof over the nest of a swift, the dam notwithstanding sat 
in the nest: so strongly was she affected by natural love for her 
brood, which she supposed to be in danger, that, regardless of her own 
safety, she would not stir, but lay sullenly by them, permitting her- 
self to be taken in the hand. 
Swifts are much infested with those pests to the genus called hip- 
poboscae hirundinus, and often wriggle and scratch themselves in 
their flight, to get rid of that clinging annoyance ; and young ones, 
overrun with these insects, are sometimes found under their nests, 
fallen to the ground, the number of vermin rendering their abode 
insupportable. Swifts have only one harsh screaming note ; yet 
there are ears to which it is not displeasing, from an agreeable asso- 
ciation of ideas, since that note never occurs but in the most lovely 
summer weather. They never settle on the ground but through acci- 
dent ; neither can they w'alk, but only crawl ; but they have a strong 
grasp with their feet, by which they cling to walls. Their bodies 
being flat, they can enter a very narrow crevice ; and where they 
cannot pass on their bellies, they will turn up edgew^ays. In London, 
a party of swifts frequents the Tower, playing and feeding over the 
mire just below the bridge ; others haunt some of the churches of the 
Borough next the fields, but do not venture, like the house-marten, 
into the close crowded part of the town. 
The Swedes have bestowed a very pertinent name bn this swallow, 
calling it ring-swallow, from the perpetual rings or circles that it takes 
round the scene of its nidification. As these birds are apt to catch 
at every thing on the wing, many have taken them by the bait of a 
cockshafer tied to a thread, which they have swallowed as freely 
as a fish swallows a baited hook. In the isle of Zante, the boys are 
said to get on an elevated place, and, merely with a hook baited with 
a feather, have caught five or six dozen of them in a day. Besides 
