FEA THERS 



243 



more Filoplumes arise. Their development shews them to be 

 degenerate and not primitive feathers. In most cases they are 

 concealed, but not unfrequently a few elongated Filoplumes project 

 beyond the feathers of the neck, as in Fringilla, Sylvia, Turdus, and 

 above all in Criniger. According to Nitzsch, the delicate white 

 feathers on the neck and thighs of the Cormorant in breeding- 

 plumage are comparatively little degenerated and rather specialized 

 Filoplumes. 



The first clothing of the newly-hatched bird consists of more 

 or fewer soft feathers, on the whole resembling the Downs of adult 

 birds ; but possessing several characters which make it advisable to 

 distinguish them, by the name of " Neossop tiles " (veoo-o-os, a chick), 

 from those feathers which subsequently appear, and may be called 

 " Teleoptiles " (reAeos, mature), the former being as it were the first 

 generation to which others follow in constant succession (Moult), so 

 long as the bird lives. 



Neossoptiles are characterized by (1) a very short calamus, (2) 

 an insignificant or ill-defined rhachis — if there be one at all, (3) 

 the almost universal absence of cilia, (4) long and slender rami, and 

 (5) absence of an aftershaft, except in Dromseus. To the combina- 

 tion of these characters is due the soft or downy structure of these 

 feathers. 



Teleoptiles, whether Contour-feathers or Downs, are each originally 

 preceded by a Neossoptile, the base of which is in direct continuity 

 with the tips of the rami of its succeeding final feather ; but, owing 

 to a shortened process of development or csenogenetic conditions 

 (as before described, p. 14), many, or even all Neossoptiles may 

 occasionally be suppressed, so that the tips of the first feathers 

 which appear are actually those of the second generation. This is 

 the case with Passeres, and many of the other NiDlCOL^ which breed 

 in holes, and thus seem not to need a nestling plumage. In these 

 {Passeres and Psittaci especially) the Neossoptiles, complicated 

 structures as they are, grow on but a few parts — notably on the 

 top of the head, the humeral and spinal tracts. Subsequently they 

 appear on the extremity of the future wing and tail-quills, but 

 they are very sparse on the ventral surface. In the Kingfishers 

 and Woodpeckers, and probably in other PlCARliE, the Neossoptiles 

 are almost Avholly suppressed. On the whole, this plumage is best 

 developed in the Nidifug^, and is naturally thickest in those of 

 them which early take to an aquatic life ; but it is thick at the 

 time of hatching in Piatitse, Gallinx, Spheniscidai, Anseres, Phoeni- 

 coptenis, Cohjmbo-Podicipedes, Laro-Limicolae, Pterocleidse and Gixdlse, as 

 well as in Accipitres and Striges among the Nidicolse, while on the 

 other hand in the majority of the last — even in the Pelargi, 

 Herodii, and Steganopodes — it is at birth very scanty or even absent. 

 Lastly, in the Megapodiidie- the Neossoptiles are cast off before the 



