ROOKS AND ROOKERIES. 57 



of the most pleasant sounds that greets the ear in spring- 

 time. 



The Rook is perhaps most destructive in seed-time, 

 especially in spring ; but during all the other months of 

 the year he subsists on the various grubs and worms 

 which are the terror and the pest of the agriculturist. 



In Eastern Siberia, in China and Japan, the Rook is 

 replaced by a very closely allied species, the Corvus 

 pastinator of Gould. Its plumage is glossed with reddish 

 purple instead of steel blue as in the common Rook ; 

 but the most interesting point of distinction lies in the 

 fact that the base of the upper mandible alone is devoid 

 of feathers, the throat being covered with feathers as in 

 the Carrion Crow. 



