_Series No. IX._--In this experiment the objects, which were of granite-gray cardboard, were exactly alike, but were exposed at different times and places. After the first had been exposed five seconds alone, it was covered by means of a sliding screen, and the second was then exposed for the same length of time, the interval between the two exposures being also five seconds. Two observations were made with each pair, the first exposure being in one case to the left and in the other case to the right. The object here was, of course, to determine what, if any, advantage the more recent of the two locally different impressions would have in the course of ideation. The table shows that the image of the object last seen had so far the advantage in the ideational rivalry that it remained in consciousness, on the average, almost three times as long as the other, the average being, for the first, 12.64 seconds; for the second, 36.45 seconds. And both the individual averages and the averages for the several pairs show, without exception, the same general tendency. The notes show, further, that the image of the figure first seen was not only less persistent but relatively less vivid than the other, though the latter was not invariably the case. One subject had 'an impression that the images were farther apart' than in the series where the exposure of the two objects was simultaneous, though the distance between the objects was in all cases the same, the time difference being, apparently, translated into spatial terms and added to the spatial difference. The sort of antagonism which temporal distinctions tend, under certain conditions, to set up between ideas is illustrated by the remark of another subject, who reports that 'the attention was fairly dragged by the respective images.' And the fact of such antagonism, or incompatibility, is confirmed by the extremely low figure which represents the average time when both images were reported present at the same time. The two images, separated by processes which the time interval implies, seem to be more entirely incompatible and mutually inhibitory than the images of objects simultaneously perceived. For not only does the advantage of a few seconds give the fresher image a considerable preponderance in its claim on the attention, but even the earlier image, after it has once caught the attention, usually succeeds in shutting out the other from a simultaneous view. TABLE X.