OF SELBORNE. 125 
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 reas- 
sumes its song. 
LETTER XL. 
Selborne, Sept. 2, 1774. 
Dear Sir,—BeroreE your letter arrived, and of 
my own accord, I had been remarking and compa- 
ring 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 
pulli; 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 chimneys the one for the 
other. From all my observations, it constantly 
appeared that each sort has the long feathers in its 
tail that give it that forked shape ; with this differ- 
ence, 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 a jarring 
noise, and also a snapping or cracking, pursuing 
people along the hedges as they walk: these last 
sounds seem intended for menace and defiance. 
The grasshopper-lark chirps all night in the 
height of summer. 
Swans turn white the second year, and build 
their nests the third. 
Weasels prey on moles, as appears by their being 
sometimes caught in moletraps. 
