n the water. The latter
could do it readily. The indications are that both animals profited by
seeing human beings turn on the water. This unquestionably attracted
their attention to the faucet, and probably by playing with it they
accidentally happened upon the proper movement. At any rate, Skirrl's
behavior was significant in this connection, for he would pick up the
hose to see if water were flowing, and if it were not, he would throw it
down, go directly to the faucet, and try to turn the wheel. The
association of the wheel with the desired flow of water was therefore
definitely established. Shall we describe the act as ideational? It
seems the natural thing to do.

3. Sobke, _Pithecus rhesus_

_Box Stacking Experiment_

For this test, in the case of Sobke, three light boxes made of redwood
about one-third of an inch thick were used. The smallest, box 1, was six
inches in each direction, the next larger, box 2, was twelve inches, and
the third, box 3, eighteen inches. As in the case of the other animals,
bait, either banana or carrot, was suspended from the middle of the roof
of the large cage at such distance from the floor as to be reached by
the animal only by the use of the boxes.

The first observations on Sobke were made on June 14. The three boxes
had been placed in the form of a pyramid directly under the banana,
which hung about eighteen inches above the uppermost box. Sobke's
attention while in his cage had been attracted to the bait by seeing me
fastening it in position, but when admitted to the large cage, he simply
glanced at it and then wandered about the cage, picking up bits of food
and struggling to get at the other monkeys. This he did for about five
minutes. He then went to the boxes, placed his hands on top of the
bottom one, but did not climb up on it. A few minutes later he returned
to the box again, climbed up, and readily reached the food, which he ate
while resting on boxes 1 and 2.

I now replaced the bait and gave the monkey a second chance to obtain
it. Almost immediately he climbed up as far as the second box, but
although he could reach the banana only from the uppermost box, he
deliberately shoved it off to the ground and sat down upon box 2. As he
was unable to obtain the banana from this, he soon began to gnaw and
pull at it, and as he was succeeding all too well in his efforts to tear
the box to pieces, he had to be returned to his cage.

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