related to the hypothesis of anæsthesia during eye-movements. If we
accept the interpretation of Schwarz, there is one retinal process
which is perceived as two luminous streaks in space, localized
differently and referred to different moments of time. It is
surprising, then, that a continuous retinal process is subjectively
interpreted as two quite different objects, that is, as something
discontinuous. Where does the factor of discontinuity come in? If we
suppose the retinal disturbance to produce a continuous sensation in
consciousness, we should expect, according to every analogy, that this
sensation would be referred to one continuously existing object. And
if this object is to be localized in two places successively, we
should expect it to appear to move continuously through all
intervening positions. Such an interpretation is all the more to be
expected, since, as the strobic phenomena show, even discontinuous
retinal processes tend to be interpreted as continuously existing
objects.

On the other hand, if there were a central anæsthesia during
eye-movement, the continuous process in the retina could not produce a
continuous sensation, and if the interval were long enough the image
might well be referred to two objects; since also, in the strobic
appearances, the stimulations must succeed at a certain minimal rate
in order to produce the illusion of continuous existence and movement.

This consideration seemed to make it worth while to perform some
experiments with the falsely localized after-images. The phenomenon
had also by chance been noted in the case of the eye moving past a
luminous dot which was being regularly covered and uncovered. The
appearance is of a row of luminous spots side by side in space, which
under conditions may be either falsely or correctly localized. Since