WSS Dwicut, Moult of Quails and Grouse. 43 
1900 
out, this fifth stage is reached through the first postnuptial moult, 
-the Ptarmigans alone assuming a supplementary winter dress by 
an extra moult of limited extent. Differences of plumage 
between young and old now wholly vanish, except that at later 
moults, with age, colors are supposed to deepen, but the actual 
age of a bird becomes a matter of conjecture. Birds in this dress 
can be told from birds of the year by osteological and histo- 
logical characters, but there is often nothing characteristic in 
their plumage. 
6. Second or Adult Nuptial Plumage.— Like the first nuptial this 
plumage may be only that of the winter plus wear (as it is in many 
females) or it may be partly renewed by an incomplete prenuptial 
moult confined to insignificant areas about the head, or, in the case 
of the Ptarmigans, extending over larger areas. It may be distin- 
guished from the first nuptial in a very few cases only and passes 
into that of the third winter by a complete postnuptial moult. 
So it is that plumages and moults will follow each other during 
the lifetime of a bird and a full comprehension of the systematic 
and harmonious workings of natural fundamental laws will go far 
towards dispelling the hazy ideas that have prevailed regarding 
both plumage and moult. ’ . 
LT. Moult of the Individual Species. 
Colinus virginianus (Zzv.). BOB-WHITE. 
Natal Down. — Above chiefly chestnut, buff on sides of head 
with black streak behind the eye. Below grayish buff, palest on 
chin, browner on the sides. There is a dearth of specimens 
showing the transition into the next plumage. 
Juvenal Plumage, acquired by a complete postjuvenal moult. 
Above dull brown, the feathers with white shaft-lines widening 
at the tip, the feathers of the nape and back with terminal black 
spots on the inner webs; crown dusky, gray laterally without 
shaft-lines, rump pale brown with faint whitish edgings. Wings 
and tail dull mouse gray with pale buff-mottled edgings on the 
primaries, whitish mottling on the rectrices; the secondaries and 
