102 MR. JOHN HANCOCK ON RECENT 
All the specimens I have seen were in the moult, with the 
exception of that which occurred in November. They cast their 
feathers very gradually, as evinced by the fact, that though 
moulting when they first made their appearance in May, they had 
not completely changed all their plumage in October. The 
feathers are cast symmetrically, the corresponding quills of the 
wings falling out at the same time. Hence the flight of the 
bird is very little impeded, and it may be inferred that its 
powers of flight are maintained during the moult; probably to 
enable it to accomplish its extensive migrations. 
The moult of the falcons is regulated in the same manner, as 
it is necessary that these rapacious birds should always be able 
to out-fly their prey. On the other hand, some birds, as for 
instance, many of the ducks, cannot fly at all during the period 
of moult, which however, in such cases is always very rapid. 
All the specimens that have come through my hands, were 
mature, as proved by the state of their bones as well as by the 
plumage. They were in good condition and weighed pretty 
uniformly half a pound each. 
The reproductive organs, in both sexes, were in a low state 
of development in all that I have examined. From this we 
may infer that the breeding season had passed before the birds 
reached this country. This might likewise be assumed from the . 
fact that they appeared and continued in flocks from the first 
till the last, and from their being in the moult, which usually 
commences after the breeding season is over. 
My friend Mr. Alfred Newton, has reminded me that some of 
the grouse continue shedding their feathers throughout the whole 
of the breeding season. ‘This is certainly the case; but this 
moult which precedes and is frequently continued into the 
breeding season, is only the partial spring or nuptial moult, 
during which neither the quills nor tail feathers are changed. 
The general moult does not commence even in the grouse, or in 
any of those birds which acquire a nuptial dress, until the 
breeding time has passed. The sand-grouse has apparently no ~ 
nuptial plumage, consequently no spring moult. And it is 
quite certain that when these birds arrived, in such numbers, on 
