42 Dwicut, Moult of Quatls.and Grouse. ren 
Any autumn bird that shows remains of the follicles about the 
two distal primaries and one or two mature feathers intervening 
between them and newly developed primaries further on in the 
series may always be set down as a young bird. In the adult 
the moult proceeds uniformly from the tenth to the first, so that 
if the two distal show immaturity and the remainder are all fully 
grown, the bird may be set down as an adult. This is true of all 
the Quails and all the Grouse. 
The first winter plumage assumed, according to species, during 
September, October and November, is worn until the following 
April or May and in the case of the Ptarmigans of northern lati- 
tudes even into June, when either a prenuptial moult of limited 
extent takes place or a bird may be said to have passed into first 
nuptial plumage without moult, and by wear alone. 
4. first Nuptial Plumage.— This is a fourth stage which is 
chiefly the first winter plumage plus an inconspicuous amount 
of wear, but a limited prenuptial moult renews a small part of the 
old plumage. The Quails and Grouse, most of them, assume new 
feathers limited to the throat patch of white, black or buff, which 
come in of very nearly the same color and pattern as the old, and 
to the sides of the head and forehead. ‘The Ptarmigans assume 
dark feathers over larger areas, only the wings, tail, abdomen and 
flanks remaining white, but the individual variation is considerable. 
This dress is commonly known as the breeding plumage. Just. 
as soon as a pair of birds have started their brood in life, they 
undergo the first postnuptial moult, the male beginning the process 
in advance of the female. The Arctic Ptarmigans may begin early 
in July, the Grouse and the Quails usually in August or perhaps 
September, in some cases. ‘This moult is invariably complete 
with the possible exception of a few feathers, and the slight differ- ° 
ences between old and young which may have persisted up to this 
period are now practically obliterated and all subsequent plumages 
may be called adult. The year old Ptarmigans, like the birds 
of the previous autumn, assume a’plumage reddish or dusky 
over the superior and anterior regions of the body, and a supple- 
mentary first postnuptial moult takes place by which the dark 
areas are renewed by white. 
5. Second or Adult Winter Plumage. 
As I have just pointed 
