128 BRITISH BIRDS. [vol. vir. 



Bedford, who has allowed her keeper, Mr. John Clark, to 

 send me specimens from Bedfordshire ; and to Mr. Hugh 

 S. Gladstone, who has similarly permitted his keeper, 

 Mr. Charles Hyslop, to send me Rooks from Dumfriesshire. 

 These two keepers have very kindly supplied specimens 

 of all ages with great regularity, and without such a 

 complete and large series it would have been quite 

 impossible to have solved this somewhat intricate 

 problem. I am also indebted to Mr. Abel Chapman for 

 some specimens sent from time to time. My grateful 

 thanks are also due to Miss A. C. Jackson, who has not 

 only provided me with a number of useful skins and 

 notes, but has most kindly mounted many feathers for 

 microscopical examination. 



I have examined eighty-three specimens in the flesh 

 and have kept very careful notes of the condition of the 

 plumage and sexual organs, and have either preserved 

 the whole skin or the head and wing. 



Part I. — The Moult of the " Face." 



The full sequence of the plumages of the Rook will be 

 given below (see part ii.), but I will first describe the 

 process by which the " face " becomes bare. 



As is well known, the Rook in its juvenile-plumage 

 has the " face " normally feathered hke that of a Carrion- 

 Crow {Corvus cor one) — that is to say, the nostril-region 

 extending to the base of the skull is covered with bristle- 

 like feathers ; similar, but smaller bristles, as well as 

 small contour feathers, grow on the sides of the lower 

 mandibles at their bases, and on the lores, while small 

 feathers are found on the region under the eyes, and 

 feathers clothe the chin and upper-throat — all of which 

 parts become bare in the adult. A closer examination 

 reveals the fact that a number of minute filoplumes or 

 hair-like feathers grow amongst the nostril-bristles, 

 and that larger filoplumes as well as many plumules, 

 or down-like feathers, are concealed amongst the contour 

 feathers of the chin and throat. 



