100 COR VIDE. 



The female is frequently, in her whole length, two inches 

 shorter than the male, and has less brilliancy in the 

 plumage. 



Young birds of the year resemble the adult female ; but 

 the feathers at the base of the beak, projecting forward over 

 the nostrils, are not replaced after the first moult, and two or 

 three other birds (not British) are now known to exhibit this 

 peculiarity, which has been considered specific. 



White, pied, and cream-coloured varieties of the Rook 

 sometimes occur. Mr. Hunt, of Norwich, says, " A gentle- 

 man of his acquaintance had in 1816 a young Rook of a light 

 ash-colour, most beautifully mottled all over with black, and 

 the quill and tail-feathers elegantly barred. This curiosity 

 he was naturally anxious to keep ; when upon the bird moult- 

 ing, all its mottled plumage vanished entirely, — it became a 

 jet black Rook, and in this state w^as suffered to join its 

 sable tribe, as a fit companion, in the fields."" This agrees 

 with my own observations. Accidental varieties will gene- 

 rally be found to be smaller and weaker birds than those which 

 are truly characteristic of the species. As these young birds 

 increase in age, and gain constitutional power, the secretions 

 become perfect, and the plumage assumes its natural colours. 

 The assumption of white feathers by old birds is probably the 

 effect of the converse operation of this physiological law. 



Malformations of the beak are by no means uncommon 

 among the species of the genus Corvus, particularly in the 

 Rook, (see page 90,) and some remarks by John Blackwall, 

 Esq. in his Researches in Zoology, refer to a question not 

 yet entirely set at rest. 



" A Rook preserved in the Manchester Museum, has its 

 mandibles crossed near their extremities, but so slightly, as not 

 to have interfered materially with the mode of procuring 

 food usually employed by that species, as is clearly evinced 

 by the denuded state of the nostrils and the anterior part of 



