2^1 



this view, there is also a certain amount against it, 

 with the result that the prevailing opinion amongst 

 modern ornithologists is that the patch is natural to 

 the species and not an acquired character of the 

 individual. Blackwell, after saying that he once saw 

 a Rook with its beak so deformed that it could not 

 possibly dig, and that it did not show the bald patch 

 (thus pointing towards the popular opinion), goes on 

 to recount that a young bird, which he moulted in a 

 pen, cast off the face feathers in this first moult and did 

 not renew them in either of the two which it lived long 

 enough to undergo subsequently. He therefore was of 

 the opinion that "the phenomenon . . . has a physio- 

 '* logical, not a mechanical cause, though the removal 

 ''of the plumage may be facilitated b}^ the frequenth^ 

 " repeated act of thrusting the bill into the ground." 

 Waterton also records in his Essays an experiment, 

 which, although abortive, yet seemed to point to 

 Blackwell's conclusion. The evidence afforded by the 

 bird which originally prompted this paper is as 

 follows : — Caught on June 5th, 1900, he had the run of 

 my garden during August, and moulted during 

 September and October. His owner says : " He died 

 " in July, 1901. He never lost the bristles at the base 

 " of his beak. The beak was never bare of tin}^ 

 " feathers. I thought this was because he never had 

 "to dig for his living." 



Dr. Bowdler Sharpe says it is certain that the 

 3'oung birds retain their feathered face after their 

 first moult and carry it through their first winter ; and 

 that though most of them lose it in the spring, there 

 have been killed several specimens which even in 

 May had only partially bare faces. 



