NATURAL HISTORY OF SELBORNE. 



spect to them, and different from all other birds, I might perhaps 

 be credited ; especially as my assertion is the result of many 

 years' exact observation. The fact that I would advance is, that 

 swifts tread, or copulate, on the wing : and I would wish any 

 nice observer, that is startled at this supposition, to use his own 

 eyes, and I think he will soon be convinced. In another class 

 of animals, viz. the insect, nothing is so common as to see the 

 different species of many genera in conjunction as they fly. The 

 swift is almost continually on the wing ; and as it never settles 

 on the ground, on trees, or roofs, would seldom find opportunity 

 for amorous rites, was it not enabled to indulge them in the air. 

 If any person would watch these birds of a fine morning in 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 in- 

 variably 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. 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 even- 

 ing, 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 thundry 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 



* This is a mistake ; three and even four eggs are not uncommon. But, if their first produce 

 be taken away, I believe that two eggs are the maximum which are laid afterwards. Of seven 

 nests, all of them containing eggs, which were removed by a correspondent of Loudon's Maga- 

 zine, two of them contained only a pair, four had three, and one had as many as four eggs in 

 it. On examining the same situation five weeks afterwards, eight new nests had been constructed, 

 each of them containing ouly a pair of either eggs or young. ED. 



