was satisfied when I found that the lighter point is displaced toward
the heavier, in short distances. A further explanation of these
figures will be given in connection with similar figures in the next
section.

[Illustration: FIG. 2. Back of hand.]

[Illustration: FIG. 3. Forearm.]

This attraction of the heavier for the lighter points is, I think, a
sufficient explanation for the variations in judgments upon filled
distances where changes are made in the place at which the pressure is
applied. I furthermore believe that an extension of this principle
offers an explanation for the underestimation of cutaneous
line-distances, which has been frequently reported from various
laboratories. Such a straight line gives a subjective impression of
being heavier at the center. I found that if the line is slightly
concave at the center, so as to give the ends greater prominence and
thereby leave the subjective impression that the line is uniform
throughout its entire length, the line will be overestimated in
comparison with a point distance. Out of one hundred judgments on the
relative length of two hard-rubber lines of 5 cm. when pressed against
the skin, one of which was slightly concave, the concave line was
overestimated eighty-four times. For sight, a line in which the shaded
part is concentrated at the center appears longer than an objectively
equal line with the shading massed towards the ends.


IV.