OF SELBORNE. 
121 
a snapping or cracking, pursuing people along tlie 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 breed the third. 
Weasels prey on moles, as appears by their being some- 
times caught in mole- traps. 
Sparrow-hawks sometimes breed in old crows^ nests, and 
the kestril in churches and ruins. 
There are supposed to be two sorts of eels in the island 
of Ely.^ The threads sometimes discovered in eels are 
perhaps their young 3 the generation of eels is very dark 
and mysterious.^ 
Hen-harriers breed on the ground, and seem never to 
settle on trees. 
When redstarts shake their tails they move them hori- 
zontally, as dogs do when they fawn ; the tail of a wagtail, 
when in motion, bobs up and down like that of a jaded 
horse. 
Hedge-sparrows have a remarkable flirt with their wings 
in breeding time ; as soon as frosty mornings come they 
make a very piping plaintive noise. 
Many birds which become silent about Midsummer, re- 
assume their notes again in September ; as the thrush, 
blackbird, woodlark, willow wren, &c. ; hence August is by 
much the most mute month, the spring, summer, and autumn 
through. Are birds induced to sing again because the 
temperament of autumn resembles that of spring ? 
Linnaeus ranges plants geographically; palms inhabit 
the tropics, grasses the temperate zones, and mosses and 
lichens the polar circles ; no doubt animals may be classed 
in the same manner with propriety. 
1 Three species of eels are described and figured in Yarrell's " History 
of British Fishes." But see antea, p. 39, note 2. — Ed. 
^ Eels are infested by several kinds of intestinal worms, which are 
doubtless the thread-like bodies referred to. The observations made 
by the late Mr Yarrell on the reproduction of eels leave little doubt 
that they spawn like other fishes. — Ed. 
