40 Dwicut, Moult of Quails and Grouse. fn 
innermost secondaries) is well developed, and their growth is so 
slow that the primary adjacent (the third) is often free of the 
persistent scale-like sheath, the remains of its follicle, before the 
quills of these two feathers have lost their pulpy look. In con- 
sequence of this, the postjuvenal moult, beginning with the loss of 
the tenth primary often before they are grown, reaches them in 
some cases before they have lost their signs of immaturity. They 
are not moulted, but retained for a twelvemonth, while the rest 
of the remiges are renewed by the postjuvenal moult. The distal 
pairs of primaries therefore belong to the juvenal plumage, while 
the rest are truly a part of the first winter dress. This peculiarity 
is not at all striking among the brown-quilled species, but in Zago- 
pus it has doubtless occasioned some of the misunderstandings 
that have prevailed regarding the moult of the Ptarmigans. In 
these birds the two distal primaries are white when first developed, 
while the rest of the remiges are brown until renewed by white 
ones at the postjuvenal moult. 
The next point at which new feather growth begins in the 
chick is on either side of the breast, spreading backwards along 
the sides, and a little later new feathers appear on the back 
at the root of the neck, upon the middle of the crown, and 
at the middle part of the humeral and femoral tracts. The ten- 
dency is to spread backwards with new points of departure ante- 
riorly on the forehead, throat, chin and sides of the head, and 
posteriorly on the rump, flanks and abdomen. The wing-coverts 
reach their full development in advance of the remiges and before 
the body plumage, the greater and lesser in advance of the median, 
and the upper coverts before the lower. ‘The chin and throat, 
sides of the head, neck, mid-abdomen and tarsi are late in losing 
the downy plumage and the rectrices are also late in their devel- 
opment. The same relative order of renewal is observable in 
later moults, plumage being renewed in very nearly the same 
order in which it originally grew. Renewal is very systematic in 
birds and if certain feathers of a tract or of a series have already 
been moulted, it is not difficult to predict when and where the 
next feather will have its place taken by a new one, provided the 
laws which govern moult, the distribution of the feather tracts and 
the peculiarities of species under consideration are known. 
