172 NATURAL HISTORY 



ever observe, they begin nesting about the middle of May ; 

 and I have remarked, from eggs taken, that they have sat 

 hard by the ninth of June. In general they haunt tall build- 

 ings, churches, and steeples, and breed only in such : yet in 

 this village some pairs frequent the lowest and meanest cot- 

 tages, and educate their young under those thatched roofs. 

 We remember but one instance where they breed out of 

 buildings ; and that is in the sides of a deep chalkpit near the 

 town of Odiham, in this county, where we have seen many 

 pairs entering the crevices, and skimming and squeaking 

 round the precipices* 



As I have regarded these amusive birds with no small atten- 

 tion, if I should advance something new and peculiar with 

 respect 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 ad- 

 vance is, that swifts tread, or copulate, on the wing : and I 

 would wish any nice observer, that is startled at this suppo- 

 sition, to use his own eyes, and I think he will soon be con- 

 vinced. 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 opportuity 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 it's 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 func- 

 tions there save those of sleeping and incubation. 



This hirundo differs widely from it's 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 



