This work of Schwarz certainly proves that the explanation of Cornelius is not correct.  Schwarz found that the phenomenon takes place as well when the head moves and the eyes are fixed relatively to the head, as when the eyes alone move.  He furthermore made this observation.  Meaning by a the point of departure and by b the goal of either the eye-or the head-movement, movement, he says (ibid., S. 400-2):  “While oftentimes the streak of the after-image extended uninterruptedly to the point b, or better seemed to proceed from this point,—­as Lipps also reported—­yet generally, under the experimental conditions which I have indicated, two streaks could be seen, separated by a dark space between; firstly the anomalous one” (the false streak) “rather brilliant, and secondly a fainter one of about equal or perhaps greater length, which began at the new fixation-point b and was manifestly an after-image correctly localized with regard to the situation of this point.  This last after-image streak did not always appear; but it appeared regularly if the light at a was bright enough and the background dark....  It was impossible for this second after-image streak to originate in the point b, because it appeared equally when b was only an imaginary fixation-point....  This consideration makes it already conceivable that the two parts of the total after-image are two manifestations of the one identical retinal stimulation, which are differently localized....  Therefore we must probably picture to ourselves that the sensation from the strip of the retina stimulated during the quick eye-movement is, during the interval of movement or at least during the greater part of it, localized as if the axis of vision were still directed toward the original fixation-point.  And when the new position of rest is reached and the disturbance on the retinal strip has not wholly died away, then the strip comes once more into consciousness, but this time correctly localized with reference to the new position of the axis of vision.  By attending closely to the behavior as regards time of both after-image streaks, I can generally see the normal after-image develop a moment later than the anomalous one” (that is, the false streak).  Schwarz finally suggests (S. 404) that probably between the first and second appearances of the streak an ‘innervation-feeling’ intervenes which affords the basis for localizing the second streak (’correctly’) with reference to the new position of the eye.

After this digression we return to consider how this phenomenon is related to the hypothesis of anaesthesia 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