[17] McDougall, _Mind_, N.S., X., 1901, p. 55, Observation II.

Now if the event of such an anæsthesia could be established, we should
know at once that it is not a retinal but a central phenomenon. We
should strongly suspect, moreover, that the anæsthesia is not present
during the very first part of the movement. This must be so if the
interpretation of Schwarz is correct, for certainly no part of the
streak could be made before the eye had begun to move; and yet
approximately the first third was seen at once in its original
intensity, before indeed the 'innervation-feelings' had reached
consciousness. Apparently the anæsthesia commences, it at all, after
the eye has accomplished about the first third of its sweep. And
finally, we shall expect to find that movements of the head no less
than movements of the eyes condition the anæsthesia, since neither by
Schwarz nor by the present writer was any difference observed in the
phenomena of falsely localized after-images, between the cases when
the head, and those when the eyes moved.


III. THE PERIMETER-TEST OF DODGE, AND THE LAW OF THE LOCALIZATION OF
AFTER-IMAGES.


We have seen (above, p. 8) how the evidence which Dodge adduces to
disprove the hypothesis of anæsthesia is not conclusive, since,
although an image imprinted on the retina during its movement was
seen, yet nothing showed that it was seen before the eye had come to
rest.

Having convinced himself that there is after all no anæsthesia, Dodge