In the movement series of the A and B sets, movements of parts of the body were chosen.  But the number of such movements which a person can conveniently make while reading words shown through an aperture is limited, and as stated above no single word was ever used in two couplets.  These were now exhausted.  In the C set, therefore, movements employing objects were substituted.  The objects lay on the table in a row in front of the subject, occupying a space about 50 cm. from left to right, and were covered by a black cambric cloth.  They were thus all exposed at the same moment by the subject who, at a signal, laid back the cloth immediately before the series began, and in the same manner covered them at the end of the third presentation.  Thus the objects were or might be all in view at once, and as a result the subject usually formed a single mental image of the four objects.

With this kind of material it was no longer necessary for the operator to show the subject in advance of the series what the movements were in order to avoid hesitation and confusion, for the objects were of such a nature as obviously to suggest in connection with the words the proper movements.

TABLE IV.

SHOWING RECALL AFTER TWO, NINE AND SIXTEEN DAYS FOR TWO SUBJECTS, AND
AFTER FIVE HOURS AND TWENTY-ONE HOURS FOR FOUR OTHER SUBJECTS.

Days.       Two.      Nine.    Sixteen     Two.       Nine.     Sixteen
N.  O.    N.  O.    N.  O.   V.    M.   V.   M.   V.   M.
Series                             M.
C^{1-4}    4   4     4   4     3   2     3     2    2    2    1    1
C^{5-8}    2   2     2   2     2   1     1     1    1    2    1    0
C^{9-12}   3   2     3   1     3   0     2     4    3    2    2    1
C^{13-16}  4   3(1)  4   2(1)  4   2(1)  3     4    2    3    2    3
Total     13   1(1) 13   9(1) 12   5(1)  9    11    8    9    6    5
Per cent. 81  73    81  60    75  33    56    69   50   56   38   31

Mo
C^{1-4}    2   4     1   1     1   1     1     4    1    2    1    2
C^{5-8}    3   2     4   1     3   1     4     3(1) 4    3(1) 2    2(1)
C^{9-12}   0   1     0   1     0   1     0     3    0    1    0    2
C^{13-16}  0   0(1)  0   0(1)  0   0(1)  1(1)  4    1(1) 2    0(1) 0
Total      5   7(1)  5   3(1)  4   3(1)  6(1) 14(1) 6(1) 8(1) 3(1) 6(1)
Per cent. 31  46    31  20    25  20    40    93   40   53   20   40

Hours.        Five.           Twenty-one.     Five.           Twenty-one
N.    O.       N.    O.       V.    M.       V.    M.
Series                             S.
C^{1-4}      1     3        1     1        0     1        0     1
C^{5-8}      0(1)  3        0     2        0     1        0     1
C^{9-12}     0(1)  3        0(1)  4        3     4        3     4
C^{13-16}    1     3        1     3        2     3(1)     3     3(1)
Total        2(2) 12        2(1) 10        5     9(1)     6     9(1)