64 



PSYCHOLOGY. 



The accompanying figure from Panetli shows jast how 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 ;t or that the 

 superficial ones in the motor region 

 are correlated wdth the extremities 

 of the organs to be moved (fingers, 

 etc.), the deeper ones with the more 

 central segments (wrist, elbow 

 etc.). X 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 

 contain nothing but a7'rangements 

 for rep7'esenting impressions and 

 movements, and other arrangements 

 for coupling the activity of these 

 arrangements together. § Currents 

 pouring in from the sense-organs 

 first excite some arrangements. 



Pig. 21. — Dog's motor centres, right 

 hemisphere, according to Paneth. 

 — The points of the motor region 

 are correlated as follows with 

 muscles: the Ziops wirh the orbi- 

 cularis palpebrarum; the plain 

 crosses with the flexor, the crosses 

 inscribed in circles with the ex- 

 tensor, digitoriim conimnnis of 

 the fore paw; the plain circles 

 with th« abductor pnllicis 

 long lis; the double crosses with 

 the extensor communis of the 

 hind-limb. 



* Priuger's Archiv, vol. 37, p. 523 (1885). 



f By Liiys in his generally preposterous book ' The Brain' ; also by 

 Horsley 



X C. Mercier : The Nervous System and the Mind, p. 134. 



§ The frontal lobes as yet remain a puzzle. Wundt tries to explain 

 them as an organ of 'apperception ' (Grundztlge 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. — Uutil quite recently it waa 



