4 
The biological fact is thus established that all the wing quills are ripe 
at practically the same time, that is, at about cight months; but the 
germs of the new feathers do not become simultaneously active so long as 
{he quills remain in the follicles, some germs become active but others do 
not. 
The growth of the new feather and the consequent pushing out of the 
eld quill would correspond with the natural moult, and, in a state of 
nature, this never proceeds simultaneously for all the wing plumes, nor in- 
deed for any of the series of feathers over the other parts of the body. In 
wild ostriches it is always found that only a few of the wing plumes are 
actually growing at one and the same time; the rest are old, over ripe 
feathers not yet moulted. The actual order according to which the 34 or 
more wing quills of the ostrich are naturally moulted has not yet been 
determined, but it is found that those at the free or distal end of the wing 
are the first to be shed, while they are closely followed by those towards 
the fixed extremity, the latest to drop out being the feathers along the 
middle of the wing. In experiments carried out to determine the quality 
of the feather growth resulting from the natural shedding of the quills it 
was found that odd feathers appeared here and there, the sequence on op- 
posite wings not necessarily corresponding. The order of moulting of the 
wing quills has been somewhat fully investigated in homing pigeons, 
where the matter assumes a great significance in the racing powers of the 
birds. It has been ascertained that the feathers are moulted in a fairly 
definite sequence, and such would probably be found to be the case in the 
estrich were a sufficient number of specimens available for such an ex- 
periment. 
A second biological fact has been established which is of the greatest 
value in ostrich management. The removal of a quill, whether ripe or un- 
ripe, at once stimulates the germ below to activity, and the new feather 
begins to appear quite irrespective of any natural sequence. The germ 
would not become active were the quill not drawn, but does so when this 
takes place. Thus by artificially removing when ripe or nearly ripe all 
the old quills, a complete new crop of feathers is secured, which likewise 
all come to ripeness at about the same time. It is this fact which renders 
the farming of the ostrich so much more satisfactory than would be the 
case if the feather growth were dependent upon the irregularities of 
natural moulting. The farmer keeps his records and from them knows 
fairly accurately when he may expect a clipping of feathers and also when 
the quills should be drawn. The first feathers are ready for clipping at 
six months, and the stumps of these are ripe for drawing at eight months; 
the second crop of feathers is ripe six months later, that is, at fourteen 
months, and the quills of these can be drawn in two months, when the 
bird is a year and four months old or thereabouts. 
As a matter of practice it is not always that one can secure the 
uniform growth of every member of a complete crop of feathers on both 
wings. Odd plumes are very lable to be trodden out in the herding of 
the birds, or to be drawn out by accident at any stage of their growth. In 
thisscase the new feather which replaces the lost one commences to grow 
at once, and is necessarily not at the same stage of growth as the others.* 
*It is an interesting fact that in young birds a feather growing out of the regular 
order corresponds in character neither with those of the crop before it nor the cron after 
it. It comes at an intermediate time and is intermediate both in its size and other features 
between the plumage before it and the plumage after it. In nature there are no sharply 
defined plumage stages in the ostriches ; one plumage passes gradually into the other, and 
the new feathers appearing at any stage represent the stage of development reached by the 
bird at that time. Until the adult plumage is reached any odd new feather differs ‘from 
those in advance of it and those coming after. 
