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ON THE PLUMAGE OF THE NESTLING 

 BARN-OWL. 



BY 

 W. P. PYCRAFT, A.L.S.,.M.B.O.TT. 



In 1907 I described, in the pages of British Bikds (Vol. I., 

 pp. 162-167) the nesthng-down of the Tawny aiid Barn 

 Owls, and in the present communication I desire to make 

 a few comments on that paper, made necessary by the 

 discovery of new facts gleaned from fresh material. 



For the sake of those readers who may not have read 

 my earlier papers on the subject of nestling-down, I may 

 remark that I have sho^^^l that in manj' birds two genera- 

 tions of nestling-do\\Ti are successively developed before 

 the typical or teleoptyle plumage appears. These two 

 generations, constituting the protoptyle and mesoptyle 

 plumages, apparently answer to degenerate, ancestral, 

 teleoptyle plumages. In a large number of species the 

 earliest of these, the protoptyle do^\^l-plumage — which is 

 the most degenerate, being formed of umbelliform feathers 

 — ^has been entirely suppressed, while in some cases a 

 like fate has overtaken the mesop)tyle dress, when the 

 3'oung remain naked till the " contour " or teleoptyle 

 feathers appear. When only one generation of nestling- 

 down is developed, we may conclude, with certainty, 

 that this is the mesoptyle generation, and that the earlier 

 one has disappeared. 



This mesoptyle dress presents a most interesting series 

 of grades of development, being most perfect — least 

 degenerate — in the Martineta Tinamou {Calodromus 

 elegans), which I described in the Ibis (1895, p. 1) from 

 specimens sent me by Dr. P. L. Sclater. In this bird 

 each feather has a well-marked scapus, or stem, bearing 

 a series of rami and radii which bear a close approximation 

 to those of the later " contour " or teleoptyle feathers. 

 In no other birds have I yet seen quite such perfect 

 ^nesoptyles. Probabh', however, the newly-hatched 



