Despite the difference in temperament and quickness in delivery, I
regard the measure of the orang-utan's mental capacity as being
equal to that of the chimpanzee; but the latter is, and always
will remain, the more alert and showy animal. The superior feet of
the chimpanzee in bipedal work is for that species a great
advantage, and the longer toes of the orang are a handicap.
Although the orang's sanguine temperament is far more comforting
to a trainer than the harum-scarum nervous vivacity of the
chimpanzee, the value of the former is overbalanced, on the stage,
by the superior acting of the chimp. For these reasons the
trainers generally choose the chimp for stage education.

The chimpanzee is not only nervous and quick in thought and in
action, but it is equally so _in temper._ It will play with
any good friend to almost any extent, but the moment it suspects
malicious unfairness, or what it regards as a "mean trick," it
instantly becomes angry and resentful. Once when I attempted to
take from our large black-faced chimpanzee, called Soko, a small
lump of rubber which I feared she might swallow, my efforts were
kindly but firmly thwarted. At last, when I diverted her by small
offerings of chocolate, and at the right moment sought by a
strategic movement to snatch the rubber from her, the palpable
unfairness of the attempt caused the animal instantly to fly into
a towering passion, and seek to wreak vengeance upon me. Her lips
drew far back in a savage snarl, and she denounced my perfidy by
piercing cries of rage and indignation. She also did her utmost to
seize and drag me forcibly within reach of her teeth, for the
punishment which she felt that I deserved.

A large male orang-utan named Dohong, under a similar test,