(/ 
10. Inferior or Lower Umbilicus.—This is the circular opening at 
the tip of the fully ripe quill, and represents the aperture through which 
the pith with the blood-vessels and nerves entered the feather from the 
skin; or rather the aperture through which the pith receded from the 
feather as the quill ripened. 
11. Feathersheath.—The growing feather before it opens out is sur- 
rounded by a thin, horny, delicate covering which is the feather-sheath. 
As the feather ripens and dries the sheath cracks and is preened away by 
the bird with its beak, and, as removed, the flue is liberated and expands. 
The middle horny covering or sheath of the pith is also preened away at 
the same time. For some reason a bird will sometimes neglect to preen 
away the feather sheath, and the feather then grows upwards as a solid 
rod, perhaps expanded a little at the tip. 
12. Feather-socket or Feather-Follicle.—This is the deep pit or hole in 
the skin occupied by the lower part of the quill, and is best seen when 
the quill is drawn. At the bottom of it is the feather-germ which gives 
rise to the new feather. When a feather is plucked, either ripe or un- 
ripe, the germ below at once commences to form a new feather. If the 
quills are drawn during very cold weather it appears as if the feather- 
germ sometimes suffers from the exposure, resulting in future “ blanks ”’ 
from some of the sockets; also if a bird is in low condition at quilling 
blanks may occur, owing to the inactivity of the feather-germ. 
All the feather-sockets which the ostrich will possess are already 
present in the chick, so that the number of feathers does not increase 
with the growth and age of the bird. 
13. Socket or Follicle-sheath.—Sometimes in drawing the spadona 
quills a thin delicate horny membrane is also pulled out. This is the 
sheath which lines the socket, and the pulling of it out does not prevent 
the formation of the next feather from the same socket as some farmers 
suppose. 
14. Tip and Butt.—The tip of the feather is the end away from the 
quill; the butt is the end next the quill. 
C. Tur PLUMAGE OF THE OsTRICH. 
By the plumage of the ostrich is understood the entire covering of 
feathers on the bird at any one time. The covering is not the same at 
all periods, for the bird varies greatly in appearance between its chick 
and adult condition, dependent upon differences in the colour and other 
characters of its feathers. Four well-marked plumages can be distin- 
guished in the ostrich, namely, the Natal, the Chick, the Juvena/, and the 
Adult. These represent four distinct kinds of feathers which each feather- 
socket on the bird can produce, but, as regards the bird as a whole, the 
passage from one stage to the other is gradual, as there is no well-defined 
moulting period in the ostrich. Until the adult plumage is reached, there 
is an intermingling or overlapping of the feathers belonging to different 
plumages. 
The characteristics of each plumage will be only briefly described. | 
1. The Natal or Birth Plumage (Fig. 2).—Like the young of many 
other birds the ostrich chick when hatched is provided with feathers in 
the form of down. This is the natal or birth plumage. The feathers con- 
sist of small tufts of rather stiff rays or barbs, differing in length, and all 
starting from about the same level, there being no central shaft and no 
quill as in later feathers. Some of the barbs of each down feather are 
prolonged into a rather coarse, curled, strap-like part, and gives a bristly, 
almost’ hedgehog-like appearance to the young chick. 
