36 
trees, during the daytime, he is very rarely seen squatting on 
a thick branch, as other apes and particularly the Gibbons, do. 
The Orang, on the contrary, confines himself to the slender 
leafy branches, so that he is seen right at the top of the 
trees, a mode of life which is closely related to the constitu- 
tion of his hinder limbs, and especially to that of his seat. 
For this is provided with no callosities, such as are possessed 
by many of the lower apes, and even by the Gibbons; and 
those bones of the pelvis, which are termed the ischia, and 
which form the solid framework of the surface on which the 
body rests in the sitting posture, are not expanded like those 
of the apes which possess callosities, but are more like those 
of man. 
An Orang climbs so slowly and cautiously,* as, in this act, 
to resemble a man more than an ape, taking great care of his 
feet, so that injury of them seems to affect him far more 
than it does other apes. Unlike the Gibbons, whose fore- 
arms do the greater part of the work, as they swing from 
branch to branch, the Orang never makes even the smallest 
jump. In climbing, he moves alternately one hand and one 
foot, or, after having laid fast hold with the hands, he draws 
up both feet together. In passing from one tree to another, 
he always seeks out a place where the twigs of both come 
close together, or interlace. Even when closely pursued, his 
circumspection is amazing: he shakes the branches to see if 
they will bear him, and then bending an overhanging bough 
down by throwing his weight gradually along it, he makes a 
bridge from the tree he wishes to quit to the next.t+ 
On the ground the Orang always goes laboriously and 
shakily, on all fours. At starting he will run faster than a 
* «They are the slowest and least active of all the monkey tribe, and their 
motions are surprisingly awkward and uncouth.”—Sir James Brooke, in the 
“Proceedings of the Zoological Society,” 1841. 
+ Mr. Wallace’s account of the progression of the Orang almost exactly cor- 
responds with this. 
