94 
ON THE CLASSIFICATION OF BIBDS. 
what has been said of them by former writers. The 
ostrich is described as having no quills, properly so 
called ; yet the wings are clothed with those lieautiful 
waving feathers so well known to every one as orna- 
ments, and each wing appears to be armed with two 
spurs, about an inch long. The cassowary, on the con- 
trary, has five naked shafts, entirely destitute of webs ; 
and the tips are pointed like the quills of the porcupine. 
The wings of the American rhea, as being the fissiros- 
tral type of the family, are consequently much more de- 
veloped than in any other. They “ stretch from tip to 
tip no less than eight feet ; but, on account of the webs 
being disunited, they are useless in flight — hanging over 
and hiding the tail.” * In the New Holland emu ( Dromi- 
ceius) the wings are again very short : they are covered 
with feathers like the rest of the body, and, when the 
bird is at rest, can scarcely be perceived. Finally, in 
the genus Apteryx, the wing is equally rudimentary : 
it is covered with feathers similarly constructed to those 
of the adjacent parts, and is so small that it is quite 
concealed by the surrounding feathers, t The foregoing 
are the only instances of abortive wings among the ex- 
isting land birds : they are entirely confined to one fa- 
mily, and appear totally incapable of being used for 
flight, or even for any especial purpose. But on turn- 
ing to such birds as inhabit the water, and whose wings 
are equally short, we find that they are constructed and 
used in a different manner. However short these mem- 
bers are among the grebes, they can still be employed 
to accelerate the speed of the bird; for, when close 
pressed, we have seen them come to the surface of the 
water, and, by a shufiling sort of flight, aided by their 
feet, escape pursuit. The awks probably do the same ■ 
but being marine birds, their precise manners do not 
appear to be known. Both families, however, have all 
the usual series of feathers, — the primaries’ second- 
aries, and tertials, — so that it is only in the ex- 
* Latham, Shaw, &c. 
+ Zool. Trans, vol. i. p. 73. 
