The behavior of the mice in the experiments, the detailed results of Tables 49 and 50, and the indices of modifiability together justify the following conclusions. Most of the ten dancers, at the end of a rest interval of eight weeks, had so far lost the habit of white-black discrimination that memory tests furnished no conclusive evidence of the influence of previous training; a few individuals seemed to possess traces of the habit after such an interval. In the case of each group of individuals re-training brought about the establishment of a perfect habit far more quickly than did the original training. This suggests the existence of two kinds or aspects of organic modification in connection with training; those which constitute the basis of a definite form of motor activity, and those which constitute the bases or dispositions for the acquirement of certain types of behavior. There are several indications that further study of the modifiability of behavior will furnish the facts which are necessary to render this suggestion meaningful. Closely related to the facts which have been revealed by the re-training experiments are certain results of the labyrinth experiments. For the student of animal behavior, as for the human educator, it is of importance to learn whether one kind of training increases the efficiency of similar forms of training. Can a dancer learn a given labyrinth path the more readily because it has previously had experience in another form of labyrinth? The answer to this question, which my experimental results furnish, is given in Table 51. In the upper half of the table have been arranged the results for six individuals which were trained first in labyrinth B, then in labyrinth C, and finally in labyrinth D. Below, in similar fashion, are given the results for six individuals which were trained in the same three labyrinths in the order C, B, D, instead of B, C, D. My purpose in giving the training in these two orders was to ascertain whether labyrinth C, which had proved to be rather difficult for most individuals, would be more easily learned if the training in it were preceded by training in labyrinth C. TABLE 51 THE INFLUENCE OF ONE LABYRINTH HABIT UPON THE FORMATION OF ANOTHER LABYRINTH B LABYRINTH C LABYRINTH D NO. OF NO. OF NO. OF NO. OF NO. OF NO. OF NO. FIRST COR- LAST OF FIRST COR- LAST OF FIRST COR- LAST OF RECT TEST FIVE COR- RECT TEST FIVE COR- RECT TEST FIVE COR- RECT TESTS RECT TESTS RECT TESTS