VOL. vii] PLUMAGES OF THE ROOK. 127 



from the bars of the cage, and the bird soon after died. 

 The only one which survived lost none of the feathers 

 on the face, and even after its second winter-moult the 

 face was fully feathered ! It is well known that birds 

 in captivity often moult most irregularly, and this is a 

 good instance of the danger of drawing conclusions 

 regarding moult and sequences of plumage from captive 

 birds. Knox, however, continued his investigations by 

 observing wild birds, and found that a small portion 

 of the nostril-bristles was lost in the winter or early 

 spring, but that the plumage of the throat was still 

 nearly perfect. He goes on to say that the rest of the 

 feathers do not disappear until the bird has paired and 

 " the calls of a hungry family urge it to dig from morning 

 till night . . . and induce it to convert the dilatable 

 skin of the throat into a convenient hunting-pouch, 

 the naked scabrous appearance of which can be no 

 mystery to any one who has narrowly observed the 

 habits of the bird at this season of the year." Although 

 he was quite correct in concluding that the " face " 

 becomes bare (though the chin is the first and the nostrils 

 are the last) when the bird is about a year old, the reason 

 he gives for this is mere supposition and he produces 

 no evidence to prove the point. 



Blackwall (Researches in Zoology, 1873) also kept 

 young Rooks in captivity, but his bird (for only one 

 survived) evidently moulted quite abnormally and did 

 not get a bare face until its second autumn-moult. 



Other writers, so far as I have read, have either quoted 

 the above-mentioned experiments, or have theorized on 

 the question, or have ignored it altogether. 



With a view to settling the point, I have during the 

 last two years or more made a close investigation of the 

 subject, which has proved full of interest. The material 

 which I have worked upon has consisted entirely of 

 wild birds, and these have been obtained in every month 

 and in nearly every week of the year. For this material 

 I am chiefly indebted to Her Grace the Duchess of 



