route through the boxes to the
starting point by being allowed to obtain food once each day in each of
the nine boxes. The procedure was simple. The entrance door and the exit
door of a particular box were raised and the animal admitted to the
reaction-compartment and permitted to pass through the box whose doors
stood open, take its food, and return to the starting point. Sobke very
quickly learned the route perfectly and came to work steadily and
rapidly. After five days of preliminary work of this sort, he was so
thoroughly accustomed to the apparatus that it was evidently desirable
to begin with regular training experiments.

The first series of trials was given on April 19. Both punishment and
reward were employed from the first. The punishment consisted of
confinement for thirty seconds in each wrong box, and the reward of a
small piece of banana, usually not more than a tenth of a medium sized
banana for each correct choice. The total time for the first series of
trials was fourteen minutes. This indicates that Sobke worked rapidly.
My notes record that he worked quickly though shyly, wasted almost no
time, made few errors of choice, and waited quietly during confinement
in the boxes. In this, also, he differed radically from Skirrl who was
restless and always tried to escape from confinement.

Throughout the work on problem 1, punishment and reward were kept
constant. Everything progressed smoothly; there were no such
irregularities of behavior as appeared in the case of Skirrl, and
consequently the description of results is a relatively simple matter.
Sobke invariably chose the end boxes. His performance was in every way
superior to that of Skirrl.

As previously, the detailed results are presented in tabular form (table
4). From this table it appears that, whereas the expected ratio of right
to wrong first choices for this problem is 1 to 2.5, the actual ratio
for Sobke's first series was 1 to .67. This surprisingly good showing is
unquestionably due to his marked tendency to choose the end box of a
group; and this tendency, in turn, may in part be the result of the
preliminary training, for during that only one box was open each time.
But, if the preliminary training were responsible for Sobke's tendency,
it should be noted that it had very different effect upon Skirrl, and,
as will be seen later, upon Julius.

The results for the ten different settings of the doors for problem 1 as
they appear in table