related to the constitution 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 forearms 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.**

[footnote] * "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.

[footnote] **Mr. Wallace's account of the progression of the
Orang almost exactly corresponds with this.