certain slight variations, in approximately ninety per cent of the
trials which involved incorrect choices. Thus, in the case of trials 121
to 130, of which eight exhibit right first choices, the remaining two
exhibit the method described above except that the final member at the
right end of the group was in each case omitted.

[Illustration: FIGURE 18.--Error curves of learning for the solution of
problem 1 (first box at left end).]

On the whole, Skirrl's behavior in connection with this problem appears
to indicate a low order of intelligence. He persisted in such stupid
acts as that of turning, after emergence from the right box, toward the
right and passing into the blind alley I, instead of toward the left,
through G and H, to D. In contrast with the other animals, he spent much
time before the closed doors of the boxes, instead of going directly to
the open doors, some one of which marked the box in which the reward of
food could be obtained. It is, moreover, obvious that his responses, as
they appear in table 1, are extremely different from those of a human
being who is capable of bringing the idea of first at the left end to
bear upon the problem in question.


_Problem 2. Second from the Right End_

Following the series of control trials of problem 1 given to Skirrl on
May 6, a period of four days was allowed during which the animal was
merely fed in the boxes each day. This was done in order that he should
partially lose the effects of his previous training to choose the first
box at the left before being presented with the second problem, the
second box from the right.