a few
seconds and then try some new method of reaching it. His gaze was
deliberate and in the handling of the boxes he accurately gauged
distances. Several times he succeeded in placing the larger box almost
directly under the banana, and repeatedly he located that portion of the
side wall from which he could most nearly reach the coveted prize.

EXPLANATION OF PLATE V

Orang utan, Julius, obtaining banana by piling boxes
or by using pole

FIGURE 21.--Julius in act of setting larger box on end.

FIGURE 22.--Placing smaller box on larger.

FIGURE 23.--Balancing on larger box preparatory to reaching for banana.

FIGURE 24.--Balancing and reaching to the utmost.

FIGURE 25.--Standing on three boxes (after stacking them) and
reaching for reward.

FIGURE 26.--Lifting smaller box up toward banana.

FIGURE 27.--The act of stacking the boxes.

FIGURE 28.--Sequel to figure 27.

FIGURE 29.--Box and pole experiment. Pushing the second pole
into the box.

FIGURE 30.--Pushing pole into box.

FIGURE 31.--Enjoying the reward of success.

From my notes I quote the following comment on the results of the
initial experiment: "Despite all that has been written concerning the
intelligent behavior of the orang utan, I was amazed by Julius's
behavior this morning, for it was far more deliberate and apparently
reflective as well as more persistently directed toward the goal than I
had anticipated. I had looked for sporadic attempts to obtain the
banana, with speedy discouragement and such fluctuations of attention as
would be exhibited by a child of two to four years. But in less than ten
minutes Julius made at least ten obvious and well directed attempts to
reach the food. There were also wanderings, efforts to obtain aid from
the experimenter, and varied attempts to escape from the cage."

Before proceeding further with the description of the behavior of Julius
in the box stacking test, I shall describe for contrast the behavior of
a boy three years four months of age when confronted with a situation
practically identical with that which the ape was given an opportunity
to meet. For the child, the banana was suspended, as previously
described, from the roof of the cage. The same two boxes were placed on
the floor at considerable distances from the banana, and in addition, a
light stick, about six feet long, and a piece of board, the latter by
accident, were on the floor. The child was asked to get the banana for