his stay in a box rarely measured more than ten seconds.

As a variation in the mode of procedure, confinement for thirty seconds
was tried on June 5, but it worked unsatisfactorily and had to be
abandoned. During this series, the animal was startled by the sound from
one of the sliding bars under the floor, and in the sixth trial he
refused to work.

As improvement was very slow, varied modes of rewarding and punishing
the animal were tried in the hope of discovering a means of facilitating
the work. Among the former are the use of banana, grapes, peanuts, and
other eagerly sought foods in varying quantities, and in the latter are
included periods of confinement ranging from ten seconds to sixty
seconds. In the end, confinement of about thirty seconds, combined with
a small quantity of food which was much to the monkey's taste, gave most
favorable results.

All this time Skirrl's attention to the task in hand was seldom good. He
was easily diverted and even when extremely hungry, often stopped work
in the middle of an early trial, yawned repeatedly and finally sat down
to wait for release from the apparatus.

The results obtained during the long continued trials with this animal
in problem 2 are presented in table 2, which differs from the previously
described table, first, in that several of the trials are followed by an
asterisk to indicate that aid was given by the experimenter, and second,
in that two additional columns, headed, respectively, R and W, are
presented. These give the right and wrong first choices for each day,
whereas the two columns preceding them give the same data for each
series of ten trials. Similarly, the ratio of right to wrong choices is