ation did
Skirrl make any attempt to use a stick or any other object as a means of
drawing the food to him. Instead, he reached persistently with his arm,
pulled and gnawed at the wires which were in his way, and occasionally
picked up and gnawed or pounded with the sticks in the cage. His
attention every now and then would come back to the food, but it tended
to fluctuate rather rapidly, and in the regular period of observation,
thirty minutes, it is unlikely that he attended to the bait itself for
as much as five minutes. In this respect as well as many others,
Skirrl's behavior contrasts sharply with that of the orang utan.

The results of this experiment indicate the lack in the monkey of any
tendency or ability, apart from training, to use objects as means of
obtaining food. Ways of using objects as tools which apparently are
perfectly natural to the anthropoid apes and to man are rarely employed
by the lower primates.

_Hammer and Nail Test_

One day I happened to observe Skirrl playing with a staple in his cage.
He had found it on the floor where it had fallen and was intently
prodding himself with the sharp points, apparently enjoying the unusual
sensations which he got from sticking the staple into the skin in
various portions of his body, and especially into the prepuce.

A few days later I saw him playing in similar fashion with a nail which
he had found, and still later he was seen to be using a stick to pound
the nail with. This suggested to me the hammer and nail test.

A heavy spike was driven into an old hammer to serve as an
indestructible handle. This hammer, along with a number of large wire
nails and a piece of redwood board, was then placed in the monkey's
cage. Skirrl immediately took up the hammer, grasping the middle of the
handle with his left hand, and with his right hand taking up a nail. He
then sat down on the board, examined the nail, placed the pointed end on
the board, and with well directed strokes by the use of the head of the
hammer drove the nail into the board for the distance of at least an
inch. He then tried to pull it out, but was forced to knock it several
times with the hammer before he could do so.

This performance, during the next few minutes, was repeated several
times with variations. Often the side of the hammer was used instead of
the head, and occasionally, as is shown in figure 8 of plate II, he
seized the hammer well up toward the juncture of the same with the