After a few preliminary experiments, figures were devised for the purpose of testing the effect of mere difference in the complexity of outline. That is to say, the members of every pair of objects were of the same uniform color-tone (Bradley's neutral gray No. 2), presented the same extent of surface (approximately 42 sq. cm.), were exposed simultaneously for the same length of time (5 seconds), and were in contour usually of like general character save that the bounding line in the one was more interrupted and complex than in the other. In another series the variant was the extent of surface exposed, the color-tone (neutral gray), outline, and other conditions being the same for both members of each pair. The smaller figures were of the same area as those of the preceding series; in the larger figures this area was doubled. Only one member of each pair is represented in the diagrams of this and the next series. In a third series brightness was the variant, one member of each pair being white and the other gray (Bradley's cool gray No. 2). All other conditions were for both figures the same. In still another series strips of granite-gray cardboard half a centimeter wide were cut out and pasted on black cards, some in straight and some in broken lines, but all of the same total length (10 cm.). These were exposed under the same general conditions as those which have already been described, and were intended to show the relative effects of the two sorts of lines. TABLE I. 1 2 3 4 5 Totals. Averages. L R L R L R L R L R L R L R I. 45 45 25 29 27 27 31 24 36 20 164 145 32.8 29 II. 20 25 28 28 28 19 31 31 28 14 135 117 27 23.5 III. 11 12 17 28 0 7 0 15 27 23 55 85 11 17 IV. 7 6 47 22 17 21 17 45 31 30 119 124 23.8 24.8 V. 27 33 46 36 40 31 44 31 26 35 183 165 36.6 33.2 VI. 11 14 32 29 34 21 14 35 0 46 91 145 18.2 29 VII. 36 33 30 30 50 50 22 22 52 52 190 187 38 37.4 VIII. 41 44 33 33 45 45 34 44 37 28 190 194 38 38.8 IX. 45 45 39 46 42 47 47 47 44 44 217 229 43.4 45.8 X. 40 39 24 25 19 21 21 23 18 25 122 133 24.4 26.6 XI. 51 53 52 50 42 42 42 42 42 42 229 229 45.8 45.8 334 349 373 356 344 331 303 359 341 359 1695 1754 30.8 31.9 The Arabic numerals at the head of the columns refer, in every table, to the corresponding numerals designating the objects in the diagram accompanying the table. _L_: left-hand object. _R_: right-hand object. The Roman numerals (_I_ to _XI_) indicate the different subjects. The same subjects appear in all the experiments, and under the same designation. Two of the subjects, _IV_ and _VIII_, are women.