NATURAL HISTORY OF SELBORNE 171 



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 hori- 

 zontally, 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 ? 



LinncBus 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. 2 



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 



1 Three species of British eels have now been clearly made out : two very 

 distinct by the form of the head, in the one narrow, in the other broad, and conse- 

 quently have been named sharp and broad-nosed eels. The third is of intermediate 

 form, and called the snig. Ely was famous for its eels, and is said to have derived 

 its name from the circumstance of its rents being formerly paid in eels. The 

 " threads " would be intestinal worms, perhaps Filaria. Eels are oviparous and 

 generate like most other fishes, having bony skeletons. [W. J.] 



2 Nothing in the record of Gilbert White's observations is more striking 

 than his insight into Biological problems, worked out by his successors when 

 the material for study became more plentiful. The above sentence was prophetic. 

 [R. B. S.] 



