Vol. XVII 
1g00 
Dwicut, Moult of Quazls and Grouse. 39 
which among other birds varies in structure according to family, 
-several names have been bestowed, one of the latest being neos- 
soptile, in contradistinction to teleoptile, the name applicable to 
every later feather (see Gadow, Newton’s Dictionary of Birds, 
1893, p. 243), although Mr. Wm. Palmer proposes the name 
mesoptile for the first feather which succeeds to the neossoptile. 
(See Fur Seals and Fur Seal Islands of the North Pacific Ocean, 
1899, part III, p. 424.) The structure of the natal down resem- 
bles that of the barbs or rami of the succeeding feathers with 
which its filaments are continuous, being gathered into bundles at 
the apices of the new feathers. All the Grouse and Quails at 
this stage are very similar, being everywhere yellowish or grayish 
and immaculate below, and mottled on the back and head with 
various shades of chestnut and black, with ‘a dusky mark behind 
the eye. Thereis a sort of a ruff on the nape, and in species which 
later have a crest, a tuft of longer down may mark the spot where it 
will appear. The chicks run about almost as soon as they are 
hatched, and within a few days begin to show signs of the suc- 
ceeding plumage, which is rapidly assumed by a complete post- 
natal moult. It is of the utmost importance to follow the develop- 
ment of this second plumage, to which I have given the name 
juvenal. 
2. Juvenal Plumage. —'The first signs of this second stage 
(the feathers of which have been called mesoptiles and differ in 
structure from the teleoptiles of adults) will be found near the 
middle of each wing, where the remiges and their coverts appear 
extending in both directions from the carpus so that the distal 
and the proximal members of the series are latest in their 
development. It is well to notice here that in all subsequent 
moults involving the wings the progress of the moult corresponds 
approximately in matter of time to the order of development here 
indicated. The first tract to show any moult is usually the alar, 
beginning with the proximal primary (always the tenth among the 
Grouse and Quails), the moult proceeding distally, until about 
four primaries have fallen out when it proceeds proximally towards 
the body. The Tetraonidz have one striking characteristic that 
seems to have been generally overlooked. The two distal primaries 
do not develop until the rest of the series of remiges (except the 
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