The Natural History of Se I borne 145 



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 sometimes 

 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 per- 

 haps their young : the generation of eels is very dark and 

 mysterious. 1 



Hen-harriers breed on the ground, and seem never to settle 

 on trees. 



When redstarts shake their tails they move them horizon- 

 tally, 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, black- 

 bird, 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 tem- 

 perament 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. 



House-sparrows build under eaves in the spring; as the 

 weather becomes hotter they get out for coolness, and nest in 

 plum-trees and apple-trees. These birds have been known 



1 The threads mentioned by White are intestinal worms. The repro- 

 duction of eels has only recently been satisfactorily understood. They 

 never spawn in rivers, but deposit their eggs and hatch out the young in 

 the deep sea. ED. 



K 



