PASSERINE BIRDS OF NEW YORK 99 



adhere at its apex or at the apices of its barbs, especially about 

 the head, for some time, after the youngster has left the nest. 

 Their color is usually pale browni, gray or white, but unfortu- 

 nately many of the specimens I have examined are young birds 

 that have been dropped into alcohol without note having been 

 made of the color when fresh. 



This ** nest-down " or as it might most appropriately be called 

 natal down represents a first stage of clothing in young birds even 

 if it be scanty or suppressed. In a systematic scheme of plum- 

 ages it must stand first although soon replaced by a second stage 

 on which the name ** first plumage" has unfortunately been 

 fastened in all good faith. Without entering into the question of 

 whether *' down " that is not true down can be called first plum- 

 age, I find it expedient, if not necessary, for the sake of uni- 

 formity and clearness to bestow a new name on the second stage, 

 reserving the numeral adjective " first " for more exact and im- 

 portant application. 



Juvenal plumage is a term definite and readily understood as 

 indicating the second plumage of a young bird which at this 

 stage usually differs in structure much from that of the adult, 

 and it is this very difference that is implied in the term I have 

 selected. The juvenal stage succeeds to the natal and feather 

 growth takes place over additional areas of skin bare during the 

 natal stage of development. The juvenal feathers differ more or 

 less in structure from those of adults, being, as a rule, weaker, 

 softer and looser in texture, as shown by the photomicrograph 

 (plate IV, fig. 1). 



During the early days of the newly-hatched chick, feather 

 growth is comparatively slow, but shortly it proceeds with 

 marvelous rapidity. A couple of weeks, more or less, accord- 

 to the size of the species, suffices to develop a helpless birdling 

 into a bold bundle of feathers ready to essay flight. The 

 feathers first fully grown are the wing coverts, those of the body 

 and top of head next appearing, while the remiges are a little 

 later and the rectrices last of all. The flight-feathers which at 

 first lie as bluish lines beneath the skin or barely protruding 

 from it, develop evenly, all the quills remaining pulpy for a con ■ 



