The Natural History of Selborne 143 



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 perhaps 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 horizontally, 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 reassume 

 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. 



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 sometimes to build in 

 rooks' nests, and sometimes in the forks of boughs under rooks' 

 nests. 



As my neighbour was housing a rick he observed that his dogs 

 devoured all the little red mice that they could catch, but rejected 



1 The threads mentioned by White are intestinal worms. The reproduction 

 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. 



