1922.] Letters, Extracts, and Notes. 219 



one case it was known that botli parents were of that 

 form too. 



If shooting-nien and their keepers could be persuaded 

 to catch and pen these birds instead of shooting them, 

 we shoukl probably be able to settle all question as 

 to their genetic constitution by a few simple breeding 



experiments. 



E. Leonard Gill. 



Hancock Museum, 



Newcastle-on-Tyue. 

 20 October, 1921. 



Nestling Plumages of Owls, 



Sir, — It seems clear from Mr. Bouhote's letter on this 

 subject in the October ' Ibis ' (pp. 755-7) that he now 

 agrees witli me so far that there is only one generation 

 of down preceding the juvenile feather-plumage in the 

 Eagle-Owl, it being understood, of course, that the various 

 generations of a feather grow from the same papilla. 



Having thus cleared the ground, it remains to be 

 decided as to whether there is another down (presumably 

 growing from papillae different from those of the feathers) as 

 Mr. Bonhote contends, or whether this is (notwithstanding 

 its down-like nature in certain tracts) a part of the juvenile 

 plumage, as I still think after a further examination of the 

 material available. A final decision on this point must, 

 I suggest, be left to that "careful further study '^ which 

 Mr. Bonhote, quite rightly, says the subject requires. 



J. H. Gurney (senr.), whom Mr. Bonhote quotes, ob- 

 tained his information from Mr. E. Fouutaine, and it seems 

 to me probable that he called the downy juvenile-feathers 

 " down,'' as many people still do. The same suggestion 

 applies to M. Lavauden's remarks and the bird he figures 

 as in " second down," and neither of these observations 

 appears to assist us greatly in determining the point. 



In the Hawks it is very clear, as I have already described 

 in 'British Birds' (Dec. 1920, pp. 154-5) and also in the 



