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64 64 PSYCHOLOGY. The accompanying figure from PanetL. shows just liow the matter stands in the dog.* I am speaking now of localiza- tions breadthwise over the brain- surface. It is conceivable that there might be also localizations depthwise through the cortex. The more superficial cells are smaller, the deepest layer of them is large ; and it has been suggested that the superficial cells are sensorial, the deeper ones motor ; f or that the superficial ones in the motor region are correlated with the extremities of the organs to be moved (fingers, etc.), the deeper ones with the more central segments (wrist, elbow, etc.). :t; It need hardly be said that all such theories are as yet but guesses. We thus see that the postulate of Meynert and Jackson which we started with en p. 30 is on the whole most satisfactorily corroborated by subsequent objective research. The highest centres do probably nothing hut arrangements imjoressioois and Fig. 21.— Dog's motor centres, right contain hemisphere, according to Paneth. -The points of the motor region fg^ representing are correlated as follows with J t" J muscles: the (aops mth the or6/- movements, and other arrangements culain^ l^alpebraruni; the plain crosses with the^exor, the crosses for COUvUng the activitv of thcSe inscribed in circles with the ex- "J sr v a j tm,sor, digitorum communis of arrangements together.^) Currents the fore-paw; the plain circles _ -^ _ -^ " ■ "" pouring in from the sense-organs excite some arrangements, with the abductor pollicis longus; the double crosses with the extensor communis of the first hind-hmb. f By Luys in his generally preposterous book ' The Brain' ; also by Horsley. X C. Mercier : The Nervous System and the Mind, p. 124. § The frontal lobes as yet remain a puzzle. Wundt tries to explain them as an organ of ' apperception ' (Grundzilge d. Physiologischen Psychologie, 3d ed.. vol. i. p. 233 ff.), but 1 confess myself unable to appre- hend clearly the Wundtian philosophy so far as this word enters into it, so must be contented with this bare reference. — Until quite recently it was
 * Pflilger's Archiv, vol. 37, p. 523 (1885).