NATURAL HISTORY OF SELBORNE. 113 



sexes, nor the individuals of different chimneys the one for the 

 other. From all my observations, it constantly appeared that each 

 sex has the long feathers in its tail that give it that forked shape ; 

 with this difference, 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 help- 

 less, 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 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 ot 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. 



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, etc. ; 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 tro- 

 pics, grasses the temperate zones, and mosses and lichens the 

 polar circles ; no doubt animals maybe classed in the same manner 

 with propriety. 



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



