of the dumb-bell seem to be of the same
intensity as in shape 2 when seen in reflex movement. But there is no
vestige whatsoever of a handle. Two of the subjects stated that for
them the place where the handle should have been, appeared of a
velvety blackness more intense than the rest of the background. The
writer was not able to make this observation. It coincides
interestingly with that of von Kries,[21] who reports as to the phases
of fading after-images, that between the disappearance of the primary
image and the appearance of the 'ghost,' a moment of the most intense
blackness intervenes. The experiments with the pendulum, however,
brought out no ghost.

[21] Von Kries, J., _Zeitschr. f. Psych, u. Physiol. d.
Sinnesorgane_, 1896, XII., S. 88.

We must now enquire why in about half the cases shape 3 is still seen,
whereas shape 5 occurs very rarely. Some of the subjects, among whom
is the writer, never saw 5 at all. We should expect that with the
intensity of _H_ sufficiently reduced 4 and 5 would appear with equal
frequency, whereas 3 would be seen no oftener than 2; shape 5
appearing when the eye did not, and 4 when it did, move at just the
rate of the pendulum. It is certain that when 4 is seen, the eye has
caught just the rate of the pendulum, and that for 3 or 5 it has moved
at some other rate. We have seen above (p. 27) that to move with the
pendulum the eye must already move decidedly more slowly than Dodge
and Cline find the eye generally to move. Nothing so reliable in
regard to the rate of voluntary eye-movements as these measurements of
Dodge and Cline had been published at the time when the experiments on
anaesthesia were carried on, and it is perhaps regrettable that in the
'empirical' approximation of the natural rate of the eye through 40 deg.
the pendulum was set to move so slowly.

In any case it is highly probable that whenever the eye did not move
at just the rate of the pendulum, it moved _more rapidly_ rather than
more slowly. The image is thus horizontally elongated, by an amount
which varies from the least possible up to 9 cm. (the width of the
opening in _T_), or _even more_. And while the last of the movement
(_O_ to _P_, or _N_ to _P'_), in which the stimulation of _H'_ is
supposed to subside, is indeed executed, it may yet be done so
_rapidly_ that after all _H'_ cannot subside, not even although it is
now less intense by being horizontally spread out (that is, less
concentrate