52 BULLETIN 107, UNITED STATES NATIONAL MUSEUM. 
belly portion is white, tinged laterally with grayish. I have not been 
able to find any specimens showing the change from the downy stage 
into the first winter plumage. The latter, however, is well repre- 
sented in collections and is well marked; it is chiefly characterized 
by the well-rounded feathers of the back and scapulars which are 
broadly edged with gray or whitish; the top of the head, hind neck, 
and rump are blackish or sooty, grading off gradually on the sides 
of the neck into the fine dusky mottling of the throat; the chin, some- 
times the throat and the underparts are white. This plumage is 
worn for nearly a year without much modification, the light edgings 
above bleaching out to white or wearing away and the throat becom- 
ing whiter toward spring. The bill is horn colored in the fall, be- 
coming darker in the spring, but never black. Probably there is an 
incomplete prenuptial molt. The postnuptial molt is complete and 
produces early in the next fall the second winter plumage, which is 
similar to the first winter plumage except that the dark crown is 
more clearly defined, the throat is pure white and the feathers of the 
back, which still have broad light edgings, are less rounded and more 
nearly square at their tips. This plumage is worn for only a short 
time in some individuals which begin to show signs of molt into the 
second nuptial plumage as early as November or December, by the 
growth of a few of the jet-black feathers with white spots on the 
back, wings, rump, and flanks; usually this molt is not much in evi- 
dence until February; from that time on the prenuptial molt ad- 
vances to the head and neck and by April or May the second nuptial 
plumage is completed. This is similar to the adult nuptial plumage, 
but is duller, more dingy, and often incomplete, with more or less 
white in the chin and throat. Specimens in this plumage have been 
found to have the sexual organs somewhat enlarged, indicating that 
the birds probably breed when about 2 years old. The bill is now 
black and never again becomes as light colored as in young birds. At 
the next postnuptial molt the young bird becomes fully adult, when 
a little over 2 years old. 
The adult winter plumage, assumed during the third fall, is char- 
acterized by the black bill and by the square tipped feathers of the 
back and scapulars, which have no light edgings but have a faint 
suggestion, a ghost as it were, of the white spot of the nuptial plum- 
age in a shade of gray only slightly lighter than the rest of the 
feather. This plumage is worn for only a short time, as in the second- 
year bird; specimens in this plumage are very scarce in collections and 
it is difficult to find one that is not either molting into it or out of 
it; the postnuptial molt into it begins sometimes by the last of August, 
but sometimes not until October; and the prenuptial molt out of it 
may begin in November or later in the winter and may not be com- 
pleted until spring. Apparently some individuals, perhaps very old 
