88 THE NATURAL HISTORY OF SELBORNE. 
the wing” ; for all the swallow kind sip their water as they 
sweep over the face of pools or rivers: like Virgil’s bees, 
they drink flying. In this method. of drinking perhaps this 
genus may be peculiar. 
The sedge-bird sings most part of the night ; its notes are 
hurrying, but not unpleasing, and imitative of several birds; 
as the sparrow, swallow, skylark. When it happens to be 
silent in the night, by throwing a stone or clod into the 
bushes where it sits you immediately set it a-singing; or in 
other words, though it slumbers sometimes, yet as soon as 
it is awakened it reassumes its song. 
LETTER XL. 
SELBORNE, Sept. 2nd, 1774. 
Before your letter arrived, and of my own accord, I had been 
remarking and comparing the tails of the male and female 
swallow, and this ere any young broods appeared; so that 
there was no danger of confounding the dams with their 
chicks: and besides, as they were then always in pairs, and 
busied in the employ of nidification, there could be no room 
for mistaking the sexes, nor the individuals of different chim- 
neys the one for the other. From all my observations, it 
constantly appeared that each sex has the long feathers in its 
tail that give it that forked shape ; with this difference, that 
they are longer in the tail of the male than in that of the 
female. 
Nightingales, when their young first come abroad and are 
helpless, make a plaintive and jarring noise; and also a snap- 
ping or cracking, pursuing people along the hedges as they 
walk: these last sounds seem intended for menace and 
defiance, 
