his answers would likely depend upon the order in which the colors
were shown, just as in determining the threshold for the perception of
two points by the method of minimal changes the answers in the
ascending series are not the same as those in the descending series.
The experiments have shown that the sensation produced by two points,
even when they are called one, is not the same as that produced by
only one point, but the difference is not great enough to suggest a
different number.

If the difference between one and two were determined by the distance,
then the substitution of lines for knobs of the æsthesiometer ought to
make no difference. And if the sensations produced by two objects fuse
when near together, then the sensations produced by lines ought to
fuse as easily as those produced by knobs.

In regard to the higher numbers difficulties will arise unless we take
the same point of view and say that number is an inference from a
sensation which is in itself a unit. It has been shown that four
points across the ends of the fingers will be called four or less, and
that four points, one on the end of each alternate finger and one at
the base of each of the others, will be called four or more--usually
more. In either case each contact is on a separate finger, and it is
hardly reasonable to suppose there is no diffusion when they are in a
straight row, but that when they are in irregular shape there is
diffusion. It is more probable that the subject regards the sensation
produced by the irregular arrangement as a novelty, and tries to
separate it into parts. He finds both proximal and distal ends of his
fingers concerned. He may discover that the area covered extends from
his index to his little finger. He naturally infers, judging from past
experience, that it would take a good many points to do that, and