y. The force to keep up the momentum of a
body moving in a horizontal plane in the air (in which there is so
little friction) cannot be great, and this force is all that is
wanted. The movement of the neck and body of the condor, we must
suppose, is sufficient for this. However this may be, it is truly
wonderful and beautiful to see so great a horde, hour after hour,
without any apparent exertion, wheeling and gliding over mountain and
river.

[Illustration]

THE UMBRELLA BIRD

(FROM TRAVELS ON THE AMAZON.)

BY SIR A. R. WALLACE.

[Illustration]

This singular bird is about the size of a raven, and is of a similar
color, but its feathers have a more scaly appearance, from being
margined with a different shade of glossy blue. It is also allied to
the crows in its structure, being very similar to them in its feet and
bill. On its head it bears a crest, different from that of any other
bird. It is formed of feathers more than two inches long, very thickly
set, and with hairy plumes curving over at the end. These can be laid
back so as to be hardly visible, or can be erected and spread out on
every side, forming a hemi-spherical, or rather a hemi-ellipsoidal
dome, completely covering the head, and even reaching beyond the point
of the beak: the individual feathers then stand out something like the
down-bearing seeds of the dandelion. Besides this, there is another
ornamental appendage on the breast, formed by a fleshy tubercle, as
thick as a quill and an inch and a half long, which hangs down from
the neck, and is thickly covered with glossy feathers, forming a large
pendant plume or tassel. This also the bird can either press to its
breast, so as to be scarcely visible, or can swell out, so as almost
to conceal the forepart of its body. In the female the crest and the
neck-plume are less developed, and she is altogether a smaller and
much less handsome bird. It inhabits the flooded islands of the Rio
Negro and the Solimoes, never appearing on the mainland. It feeds on
fruits, and utters a loud, hoarse cry, like some deep musical
instrument; whence its Indian name, _Uera-mimbe_, "trumpet-bird." The
whole of the neck, where the plume of feathers springs from, is
covered internally with a thick coat of hard, muscular fat, very
difficult to be cleaned away,--which in preparing the skins, must be
done, as it would putrefy, and cause the feathers to drop off. The
birds are tolerably abundant, but are shy, and pe