in the labyrinth became apparent when the animals were tried in a room by themselves.  They escaped much more quickly when alone.  In order to keep records of the experiments it was necessary for me to be in the room, but by keeping perfectly quiet it was possible to do this without in any objectionable way influencing the results.  It may be, however, that for this reason the learning is somewhat slower than it would have been under perfectly natural conditions.  Early in this paper reference was made to the fact that the frog did not learn to escape from a box with a small opening at some distance from the floor if it was prodded with a stick.  I do not mean to say that the animal would never learn under such conditions, but that they are unfavorable for the association of stimuli and retard the process.  This conclusion is supported by some experiments whose results are tabulated at the bottom of Table IV.  In these trials the animal had been trained to go to the left and to avoid red.  At first ten trials were given in which the frog was in no way disturbed.  The result was eight right choices and two wrong ones.  For the next ten trials the frog was touched with a stick and thus made to enter the labyrinth from the box, A.  This gave five right and five wrong choices, apparently indicating that the stimulus interfered with the choice of direction.  Several other observations of this nature point to the same conclusion, and it may therefore be said that fright serves to confuse the frog and to prevent it from responding to the stimuli which would ordinarily determine its reaction.

5. The Permanency of Associations.—­After the labyrinth habit had been perfectly formed by No. 2, tests for permanency were made, (1) after six days’ rest and (2) after thirty days.  Table V. contains the results of these tests.  They show that for at least a month the associations persist.  And although there are several mistakes in the first trials after the intervals of rest, the habit is soon perfected again.  After the thirty-day interval there were forty per cent. of mistakes at the exit for the first series, and only 20 per cent. at the entrance.  This in all probability is explicable by the fact that the colors acted as aids at the entrance, whereas at the exit there was no such important associational material.

TABLE V.

  PERMANENCY OF ASSOCIATIONS.  FROG NO. 2.

Tests after six days’ rest (following the results tabulated in Table
III.).

Trial.  Entrance.  Exit. 
Right.  Wrong.  Right.  Wrong
1-10 7 3 8 2
(110-120)
11-20 10 0 10 0