possible whatever æsthetic advantage a symmetrical arrangement might be supposed to secure. It thus appears that, whatever the effect in ideation of unity in the impression, the effect is much greater when we have complexity in unity. The advantage of unity is undoubtedly the advantage which goes with definiteness of impression, which implies definite excitations and inhibitions, and that concentration of energy and intensity of effect in which undirected activity is wanting. But a bare unity, it appears, is less effective than a diversified unity. To what extent this diversity may be carried we make no attempt to determine; but, within the limits of our experiment, its value in the ideational rivalry seems to be indisputable. And the results of the experiment afford fresh proof of the importance of the motor element in internal perception. TABLE XIII. 1 2 3 4 5 Indiv. Av. F V F V F V F V F V F V I. 25 29 26 29 29.5 26.5 25.5 30 24.5 31 26.1 29.1 II. 56 56 55 55 54 54.5 47.5 47.5 45 50 51.5 52.6 III. 2.5 5.5 2.5 8.5 6.5 5 16.5 9.5 17 15 9.0 8.7 IV. 48 48 31.5 31.5 31 46 51.5 51.5 35 52 39.4 45.8 V. 54 54 56.5 52 56 56 56 56 54 56 55.3 54.8 VI. 39 29 30 33.5 35.5 22.5 32.5 34 33.5 24.5 34.1 28.7 VII. 46 55 54.5 46.5 46.5 50 49.5 54 47 46 48.7 50.3 VIII. 9 14.5 23 20.5 23.5 22 18 14.5 16 17 17.9 17.7 IX. 43 43 46.5 46.5 45.5 45.5 43.5 43.5 46 47.5 44.9 45.2 X. 28 26.5 21 29.5 26.5 26.5 21.5 31.5 25 29 24.4 28.6 XI. 23.5 46 19.5 35.5 20 46 24 47.5 28.5 19.5 23.1 38.9 34.00 36.95 33.27 35.27 34.05 36.41 35.09 38.14 33.77 35.23 34.03 36.40 F: Figure (in outline). V: Vertical lines. General average: Figure, 34.03 sec.; vertical lines, 36.40 sec. _Series No. XIII._--In this series, also, both the figures of each pair were constituted of the same elements; that is to say, both were linear, and presented the same extent of surface (granite-gray), with the same length of line, the total length of the lines in each figure being twenty centimeters and the breadth of the lines being three millimeters. But while the lines of one figure were connected so as to form a continuous boundary, the lines of the other figure were all vertical, with equal interspaces. And, as in the last preceding series, the two figures were formed by a different but symmetrical arrangement of the same lines.