of the movement, but the movement is not intended or willed;’ ’in ideating any particular color I find my attention almost always directed to the side on which the corresponding object was seen.’  This last observation seems to be true for the experience of every subject, and, generally speaking, the images occupy the same relative positions as the objects:  the image of the right object is seen to the right, that of the left object to the left, and the space between the two remains tolerably constant, especially for the full-faced figures.

This fact suggested a means of eliminating the disturbing influence of color, and its contrasts and surprises, by the substitution of gray figures identical in form and size and distinguished only by their spatial position.  The result appears in the table which follows (VIII.).

Series No.  VIII.—­The object of this experiment was the same as that of No.  VII.  Granite-gray figures, however, were substituted, for the reasons already assigned, in place of the red and green figures.  And here the effect of additional time in the exposure is distinctly marked, the general averages showing 32.12 seconds for the image of the object which was exposed 10 seconds, as against 25.42 seconds for the other.

TABLE VIII.

1           2           3           4           5       Indiv.  Aver.
5     10    5     10    5     10    5     10    5     10    5     10
I. 26.5  27    24.5  30.5  26.5  28    27.5  27.5  26.5  29    26.3  28.4
II. 32.5  38.5  27    36    29    28    17    14.5  37.5  27    28.6  28.8
III. 4.5  13.5  11     1.5  10    11     7.5  14.5  12.5   8.5   9.1   9.8
IV. 23.5  40.5  27.5  34    35.5  38    35    28    17    39    27.7  35.9
V. 41    46    50    51.5  43    42.5  46    35.5  31.5  44    42.3  43.9
VI.  7.5  27    18    25    21.5  25.5   7    44.5  33.5  19    17.5  28.2
VIII. 24.5  27    34.5  32    36.5  36    34.5  38.5  28    28.5  31.6  32.4
IX. 17    46    25.5  47.5  44    47    40.5  47.5  48    48    35.0  47.2
X. 20    29    21    26.5  25.5  24.5  27.5  22    19.5  23.5  22.7  25.1
XI. 11    41.5   9.5  50     5.5  43.5  15.5  40.5  25.5  32    13.4  41.5
20.80 33.60 24.85 33.45 27.70 32.40 25.80 31.30 27.95 29.85 25.42 32.12

    VII.—­Absent.

     5:  refers to object exposed 5 seconds.
    10:  refers to object exposed 10 seconds.

    General average:  (5), 25.42 sec.; (10), 32.12 sec.

The interpretation of this difference may be made in accordance with the principles already laid down.  The ideated and actual movements which favor the recurrence and persistence of an idea are, on grounds generally recognized in psychology, much more likely to occur and repeat themselves when the corresponding movements, or the same movements in completer form, have frequently been repeated in observation of the corresponding object.

TABLE IX.