50 FOREHEAD OF THE ROOK. 



tagu says, that it is acquired by the bird's " habit 

 of thrusting its bill into the ground after worms and 

 various insects." From the study of Professor 

 Rennie, this error is renewed to the public, in the 

 second edition of the Ornithological Dictionary. 

 Let us look into this error. 



Every observer of birds must know that when the 

 young rook leaves its nest for good and all, there is 

 no part of its head deficient in feathers. Before 

 winter, this young bird loses the feathers on the 

 forehead, under the bill, and at the base of both 

 mandibles. The skin where these feathers grew 

 puts on a white scurfy appearance. Now, if these 

 feathers have been worn down to the stumps by 

 means of the bird thrusting its bill into the ground, 

 these stumps would fall out at the regular moulting 

 time, and new feathers would soon make their ap- 

 pearance. If, again, these feathers have been loos- 

 ened at their roots by the process of thrusting the 

 bill into the ground (which I consider next to im- 

 possible), and in consequence of this have fallen 

 out from their places, new feathers would be observed 

 in a few weeks ; for when once a feather is eradi- 

 cated, nature instantly sets to work to repair the loss 

 by producing another; nor do we know of any process 

 that can be applied with success, to counteract this 

 admirable provision of nature. Again, these new 

 feathers being full of blood at the roots, any appli- 

 cation tending to grind them down, or to eradicate 

 them, would be so painful to the rook, that it would 

 not be able to thrust its bill deep into the ground. 



