1 2 3 4 5 Indiv. Aver. V H V H V H V H V H V H I. 27.5 27 26.5 28 30.5 24.5 27.5 28.5 26 25 27.60 26.60 II. 45 43.5 37 40 35.5 28.5 19 15.5 30.5 30.5 33.40 31.60 III. 19 21 0 10.5 19.5 19 9 15 4.5 16 10.40 16.30 IV. 47.5 39 36 22.5 44.5 41.5 47.5 46 37 36 42.50 37.00 V. 56.5 46.5 42.5 42.5 48 45.5 48.5 48.5 53 52 49.70 47.00 VI. 31.5 28.5 30.5 30.5 22 34.5 34.5 28.5 25 26.5 28.70 29.70 VII. 55 55 55 45.5 38 20 55.5 53.5 56 56 51.90 45.80 VIII. 39.5 47 23.5 23.5 19 18.5 26.5 26.5 26 20.5 26.90 27.20 IX. 26.5 46 38 42.5 41 44 40.5 46.5 35.5 39 36.30 43.60 X. 24.5 25 26 25 25.5 23 23.5 28.5 32.5 20.5 26.40 24.40 XI. 52 52 56.5 54.5 48 49.5 45 47.5 51.5 47.5 50.60 50.20 38.60 39.14 33.77 33.09 33.77 31.68 34.27 34.95 34.31 33.60 34.94 34.49 _V_: Vertical. _H_: Horizontal. General average: Vertical, 34.94 sec.; Horizontal, 34.49 sec. _Series No. X._--The objects used in this experiment were straight lines, two strips of granite-gray cardboard, each ten centimeters long and half a centimeter wide, the one being vertical and the other horizontal. These were pasted on black cards and exposed in alternate positions, each appearing once to the right and once to the left. The figures in the columns represent in each case the combined result of two such observations. The experiments with these lines were continued at intervals through a number of weeks, each individual average representing the result of ten observations, or of five pairs of exposures with alternating objects. The striking feature in the observations is the uniformity of the results as they appear in the general averages and in the averages for each pair as shown at the foot of the columns. There is some variation in the individual tendencies, as shown by the individual averages. But the general average for this group of subjects shows a difference of less than half a second per minute, and that difference is in favor of the vertical line. This series will serve a double purpose. It shows, in the first place, that on the whole the vertical and the horizontal lines have a nearly equal chance of recurrence in image or idea. It will serve, in the second place, as a standard of comparison when we come to consider the effect of variations in the position and direction of lines. TABLE XI.