72 PSTCHOLOGT. a good deal more to say upon the subject when we come to the Chapter on the Will. My conclusion then is this : that some of the restitution of function (especially where the cortical lesion is not too great) is probably due to genuinely vicarious function on the part of the centres that remain ; whilst some of it is due to the passing off of inhibitions. In other words, both the vicarious theory and the inhibition theory are true in their measure. But as for determining that measure, or saying which centres are vicarious, and to what extent they can learn new tricks, that is impossible at present. FLKTAL CORKECTION OF THE MEYNEBT SCHEME. And now, after learning all these facts, what are we to think of the child and the candle-flame, and of that scheme which provisionally imposed itself on our acceptance after surveying the actions of the frog ? {Cf. pp. 25-6, supra.) It will be remembered that we then considered the lower cen- tres en masse as machines for responding to present sense- impressions exclusively, and the hemispheres as equally exclusive organs of action from inward considerations or ideas ; and that, following Meynert, we supposed the hemi- spheres to have no native tendencies to determinate activity, but to be merely superadded organs for breaking up the various reflexes performed by the lower centres, and com- bining their motor and sensory elements in novel ways. It will also be remembered that I prophesied that we should be obliged to soften down the sharpness of this distinction after we had completed our survey of the farther facts. The time has now come for that correction to be made. Wider and completer observations show us both that the lower centres are more spontaneous, and that the hemi- spheres are more automatic, than the Meynert scheme allows. Schrader's observations in Goltz's Laboratory on hemisphereless frogs * and pigeons t give an idea quite different from the picture of these creatures which is classically current. Steiner's % observations on frogs - * Pflliger's Archiv, vol. 41, p. 75 (1887). lbid., vol. 44, p. 175 (1889).
- j:Untersucliucgeu liber die Physiologic des Proschhirns, 1885.
