35° LHE HORNBILLS, 
SCANSORES, OR CLIMBING BIRDS. 
A LARGE group of birds is arranged by naturalists under the title ot 
SCANSORES, or CLIMBING BIRDS, and may be recognized by the structure of 
their feet. Two toes are directed forward, and the other two backward, so 
that the bird is able to take a very powerful hold of the substance on which 
it is sitting, and enables some species, as the woodpeckers, to run nimbly up 
tree-trunks and to hold themselves tightly on the bark while they hammer 
away with their beaks; and other species, of which the parrots are familiar 
examples, to clasp the bough as with a hand. 
There are many strange and wonderful forms among the feathered tribes ; 
but there are, perhaps, none which more astonish the beholder who sees 
them for the first time, than 
the group of birds known by 
the name of HORNBILLS. 
They are all distinguished 
by a very large beak, to 
which is added a singular 
helmet-like appendage, equal- 
ling the beak itself in some 
species, while in others it is 
so small as to attract but 
little notice. On account of 
the enormous size of the beak 
and the helmet, which in some 
<a species recede to the crown 
"of the head, the bird appears 
to be overweighted by the 
\* mass of horny substance 
(\) which it has to carry; but 
on a closer investigation, the 
whole structure is found to 
be singularly light, and yet 
very strong. 
On cutting asunder the 
beak and helmet of a Horn- 
bill, we shall find that the 
outer shell of horny sub- 
stance is very thin indeed, 
scarcely thicker than the paper on which this description is printed, and 
that the whole interior is composed of numerous honey-combed cells, with 
very thin walls and very wide spaces, the walls of the cells being so arranged 
as to give very great strength when the bill is used for biting, and with a 
very slight expenditure of material. 
Perhaps the greatest development of beak and helmet is found in the 
RHINOCEROS HORNBILL. 
As is the case with all the Hornbills, the beak varies greatly in proportion 
to the age of the individual, the helmet being almost imperceptible when it 
is first hatched, and the bill not very striking in its dimensions. But as the 
bird gains in strength, so does the beak gain in size, and when it is adult the 
helmet and beak attain their full proportions. 
When at liberty in its native forests, the Hornbill is lively and active, 
leaping from bough to bough with great lightness, and appearing not to be 
in the least incommoded by its large beak. It ascends the tree by a succes- 
