The Natural History of Selborne 243 



May, as they are sailing round at a great height from the ground, he 

 would see, every now and then, one drop on the back of another, and 

 both of them sink down together for many fathoms with a loud 

 piercing shriek. This I take to be the juncture when the business 

 of generation is carrying on. 



As the swift eats, drinks, collects materials for its nest, and, as it 

 seems, propagates on the wing, it appears to live more in the air than 

 any other bird, and to perform all functions there save those of 

 sleeping and incubation. 



This hirundo differs widely from its congeners in laying invariably 

 but two eggs at a time, which are milk-white, long, and peaked 

 at the small end ; whereas the other species lay at each brood from 

 four to six. 1 It is a most alert bird, rising very early, and retiring to 

 roost very late ; and is on the wing in the height of summer at least 

 sixteen hours. In the longest days it does not withdraw to rest till 

 a quarter before nine in the evening, being the latest of all day-birds. 

 Just before they retire whole groups of them assemble high in the air, 

 and squeak, and shoot about with wonderful rapidity. But this bird 

 is never so much alive as in sultry thundery weather, when it expresses 

 great alacrity, and calls forth all its powers. In hot mornings, 

 several, getting together in little parties, dash round the steeples and 

 churches, squeaking as they go in a very clamorous manner ; these, 

 by nice observers, are supposed to be males serenading their sitting 

 hens ; and not without reason, since they seldom squeak till they come 

 close to the walls or eaves, and since those within utter at the same 

 time a little inward note of complacency. 



When the hen has sat hard all day, she rushes forth just as it is 

 almost dark, and stretches and relieves her weary limbs, and snatches 

 a scanty meal for a few minutes, and then returns to her duty of 

 incubation. Swifts, when wantonly and cruelly shot while they have 

 young, discover a little lump of insects in their mouths, which they 

 pouch and hold under their tongue. In general they feed in a much 



1 White correctly observes the many points of difference between swifts and 

 swallows, but the ideas prevalent in his age prevent him from seeing that the 

 differences are fundamental, the resemblances superficial and adaptive only. Since 

 Darwin's time we have learned to take a different view of such questions. ED. 



