MISCELLANEOTrS OBSEETATIONS. 187 



Swans turn white the second year, and hreed 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 kestrel in churches and ruins. 



There are supposed to be two* sorts of eels iu the island 

 of Ely. The threads sometimes discovered in eels are per- 

 haps 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 taUs, they move them hori- 

 zontally, 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 breeding time : as soon as frosty mornings come, they 

 make a very piping, plaintive noise. 



Many birds which become silent about midsimimer re- 

 assume their notes again in September ; as the thrush, black- 

 bird, woodlark, wiUow-wren, &c. ; hence Augustf 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? 



LinnsBus ranges plants geographically ; pahns 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 J 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 ia the 

 forks of boughs under rooks' nests. 



* There are three species of eels. See Mr. Yarrell's work on British 

 fishes. Eels are infested with intestinal "worms, it. circumstance which has 

 induced many to suppose them to be viviparous, myself amongst the rest. 

 The generation of eels is now well ascertained. — Ed. 



-f* The robin is the only bird 1 hear sing in August. They perhaps moult 

 earlier than other song-birds, for in the moulting season birds are perfectly 

 mute.' — Ed. 



^ There two species of sparrows, — the house and the tree sparrow. See 

 Mr. Yarrell's British Birds. — Ed. 



