7 8 9 10 Averages S L S L S L S L S L I. 20.5 31.5 21.5 28.5 22.5 28 22.5 26 20.90 26.50 II. 14.5 17.5 19 20 11 4.5 7 30.5 16.10 25.00 III. 10 22 8.5 26 17 16 8 16 12.35 21.90 IV. 27.5 28.5 35 30.5 23.5 46 27.5 49.5 28.95 33.35 V. 40.5 35 24.5 22.5 21 31 21.5 21.5 35.40 36.75 VI. 22.5 18.5 11.5 21 20 27 22.5 24 21.35 21.60 VII. 44.5 46.5 52 51 33.5 49 39.5 50.5 44.85 47.85 VIII. 19.5 20 21 27 19.5 27.5 18.5 22.5 24.05 29.60 IX. 18.5 46 13 42 20 42 18.5 43 19.95 44.90 X. 18.5 24 20.5 21 20.5 22 18.5 28.5 17.00 28.75 XI. 21 49 32 53.5 38 53.5 34.5 46.5 29.00 50.15 257.5 338.5 258.5 343 246.5 346.5 238.5 358.5 24.54 33.30 _L_: large. _S_: small. General average, _S_, 24.54 sec.; _L_, 33.30 sec. _Series No. III._--In the third series, where the variant is the extent of (gray) surface exposed, the preponderance is in favor of the image corresponding to the larger object. This shows an appearance of some 33 seconds per minute as against 24 for the smaller (Table III.). Here the most obvious thing in the reports, aside from the relative durations, is the greater vividness of the favored image. Something, no doubt, is due to the greater length of boundary line and other spatial dimensions involved in the greater size. And it is this superiority, and the ampler movements which it implies, which were probably felt by the subject who reports 'a feeling of expansion in the eye which corresponds to the larger image and of contraction in the other.' But the more general comment is as to the greater vividness of the larger image. "The larger images seem brighter whichever side they are on." "The larger is a little more distinct, as if it were nearer to me." "Large much more vivid than small." Such are the reports which run through the series. And they point, undoubtedly, to a cumulative effect, corresponding to a well-known effect in sensation, in virtue of which greater extension may become the equivalent of greater intensity. In other words, the larger image made the stronger impression. Now in external perception the stronger impression tends to hold the attention more securely; that is, it is more effective in producing those adjustments of the sensory organs which perceptive attention implies. So here what was noticed as the superior brightness and distinctness of the larger image may be supposed to imply some advantage in the latter in securing those adjustments of the mental attitude which were favorable to the apprehension of that image. Advantage means here, again, in part at least, if the considerations we have urged are sound, inhibition of