OF S E L B O R N E. 
dited ; erpecially as my alTertlon is the refult of many years exaft 
obfervation. The fail that I would advance is, that iwifts //vW, 
or copulate, on the wing : and I would wiQi any nice obferver, 
that is ftartled at this fuppofition, to ufe his own eyes, and I think 
he will foon be convinced. In another dafs of animals, viz. the 
infetl, nothing is fo common as to fee the different fpecies of many 
genera in conjundion as they fly. The fwift is almoft continually 
on the wing ; and as it never fettles on the ground, on trees, or 
roofs, would feldom find opportunity for amorous rites, was it not 
enabled to indulge them in the air. If any perfon would watch 
thcfe birds of a fine morning in May, as they are failing round at a 
great height from the ground, lie would fee, every now and then, 
one drop on the back of another, and both of them fink down to- 
gether for many fathoms with a loud piercing fliriek. This I take 
to be the juncture when the bufinefs of generation is carrying on. 
As the fwift eats, drinks, colledls materials for it's nefi, and, as 
it feems, propagates on the wing ; it appears to live more in the 
air than any other bird, and to perform all fundions there fave 
thofe of lleeping and incubation. 
This hirundo differs widely from it's congeners in laying invari- 
ably but tzuo eggs at a time, which are milk-white, long, and 
peaked at the fmall end ; whereas the other fpecies lay at each 
brood ^\■omfour to fix. It is a moft alert bird, rifing very early, 
and retiring to rood very late ; and is on the wing in the height 
of f^mmer at lead fixteen hours. In the longeft days it does not 
v^/ithdraw to reft till a quarter before nine in the evening, being the 
lateft of all day birds. Juft before they retire whole groups of 
them affemble high in the air, and fqueak, and flioot about with 
wonderful rapidity. But this bird is never fo much alive as in 
faltry thundry weather, when it expreffes great alacrity, and calls 
forth 
