tion,
with the hands pendent ready to seize a rope, and climb up on the
approach of danger or on the obtrusion of strangers. He walks rather
quick in the erect posture, but with a waddling gait, and is soon run
down if, while pursued, he has no opportunity of escaping by
climbing.... When he walks in the erect posture, he turns the leg and
foot outward, which occasions him to have a waddling gait and to seem
bow-legged."

Dr. Burrough states of another Gibbon, the Horlack or Hooluk:

"They walk erect; and when placed on the floor, or in an open field,
balance themselves very prettily by raising their hands over their
head and slightly bending the arm at the wrist and elbow, and then run
tolerably fast, rocking from side to side; and, if urged to greater
speed, they let fall their hands to the ground, and assist themselves
forward, rather jumping than running, still keeping the body, however,
nearly erect."

Somewhat different evidence, however, is given by Dr. Winslow Lewis:

"Their only manner of walking was on their posterior or inferior
extremities, the others being raised upward to preserve their
equilibrium, as rope-dancers are assisted by long poles at fairs.
Their progression was not by placing one foot before the other, but by
simultaneously using both, as in jumping." Dr. Salomon Mueller also
states that the Gibbons progress upon the ground by short series of
tottering jumps, effected only by the hind limbs, the body being held
altogether upright.

But Mr. Martin, who also speaks from direct observation, says of the
Gibbons generally:

"Pre-eminently qualified for arboreal habits, and displaying among the
branches amazing activity, the Gibbons are not so awkward or
embarrassed on a level surface as might be imagined. They walk erect
with a waddling or unsteady gait, but at a quick pace, the equilibrium
of the body requiring to be kept up, either by touching the ground
with the knuckles, first on one side then on the other, or by
uplifting the arms so as to poise it. As with the Chimpanzee, the
whole of the narrow, long sole of the foot is placed upon the ground
at once, and raised at once, without any elasticity of step."

After this mass of concurrent and independent testimony, it cannot
reasonably be doubted that the Gibbons commonly and habitually assume
the erect attitude.

But level ground is not the place where these animals can display
their very remarkable and peculiar locomotive powers, and