31)0 ME. E. DEGEN ON ECDTSIS. 



Fatio (/. c. p. 252) mentions them as " Premiere livree de I'enfance," &c. From the 

 same author we also learn that the existence of the down-feathers is very brief, even in 

 those birds whose nestlings retain them during the earlier stages of development, until 

 their actual fledgling-plumage appears. 



Structurally, these feathers belong to the filo-plumaceous type (Fatio, pp. 252- 

 254, l. c), giving the young bird the somewhat silhij ' appearance of which Fatio 

 speaks. 



The filo-plumaceous feathers are either pushed or borne out on the tips of feather- 

 papillae of the more speciahzed plumage which follows on. This is formed in the 

 corium. The duration of attachment of the first livery to the new feathers varies 

 considerably; it also varies according to families. (See also Fatio, I. c. p. 26o.) 



In some it is repeated through every feather-change, as in the Struthionidce . In 

 the greater part of the Carinatce this sessile condition is confined to the first change. 

 Cases of three simultaneous attachments of feathers are known to occur occasionally, 

 of which one is mentioned by Wittmer Stone (44), p. 112, for a Meadow-Lark. This 

 author also quotes the case observed by Will. Palmer in the 'Auk,' 1894, of a young 

 Hooded Warbler, Si/lvania mitrata, in which the doion ^ of the nestling was to be seen 

 at the tip of the feather of the first plumage, while the latter was " in turn attached 1 to 

 the new feather of the winter plumage." 



In Struthious birds this latter phase seems to be of frequent occurrence, as I 

 myself have found several instances in the Emu (cf. also Fatio, I. c. p. 253). These 

 filamentous sessile plumes are to be seen in a young Columba domestica figured by 

 Pycraft (39), plate xvi. fig. 1, Avhere they are supported by the main coverts which 

 are sprouting, and reference may also be made to my figure of a young Parrakeet 

 {Platycercus eximius) (see text-figures 1 & 2), where they are clearly defined for all 

 the series of coverts and contour-feathers. 



1 have not myself had the good fortune of proving the existence of these plumes on 

 the rectrices, but an observation was made by Brehm (8), p. 346, on this point in the 

 0\yls, whose remark on it in the original is as follows: — 



" Die einjahrigen Vogel erkennt man iibrigens doch untriiglich daran dass die Spitzen 

 ihrer Steuerj^edern, weil der l^estflaum auf ihnen gesessen hat, eine kleine Lucke in der 

 Mitte zeigen " ^ 



The important nature of this passage resulted in a footnote from the Editor 

 (Dr. Cabanis) to the following effect : — '• Eine etwas suptile Wahrnehniung," &c. ; and 

 further, " die ober wohl beachtens werth scheint und jedenfalls wiederum von der 

 auerkannt scharfen Beoiachtungsiveise des Verfassers zeugt"^. 



Yet the nicety of this observation of Brehm, as pointed out by Dr. Cabanis, gains 

 in strength materially if we turn to a statement made by Blyth (4), who, on p. 260, in 



' The italics are mine. 



