126 NATURAL HISTORY 
Sparrow-hawks sometimes lay their eggs in old 
crows’ nests; and the kestrel builds in churches 
and ruins. 
There are supposed to be two sorts of eels in the 
island of Ely. 
Hen-harriers build on the ground, and seem never 
to settle on trees. 
When redstarts shake their tails, they move them 
horizontally, as dogs do when they fawn: the tail 
of the wagtail, when in motion, bobs up and down, 
like that of a jaded horse. 
Hedge-sparrows have a remarkable flirt with 
their wings in nesting time: as soon as frosty 
mornings come, they make a very piping, plaintive 
noise. 
Many birds which become silent about Midsum- 
mer, reassume their notes again in September; as 
the thrush, blackbird, woodlark, willow-wren, &e. ; 
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? 
Linnzus 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. 
House-sparrows build under eaves in the spring ; 
as the weather becomes hotter, they get out for 
coolness, and rest in plum-trees and apple-trees. 
These birds have been known sometimes to build in 
rooks’ nests, and sometimes in the forks of boughs 
under rooks’ nests. 
As my neighbour was housing a rick, he observ-. 
