CHAP. XXVI.] VOLUNTARY MOVEMENTS. 587 



contend, are the great motor ganglia through which cortical 

 stimuli resulting from so-called ' Volitional ' or Intellec- 

 tual guidance operate. If, indeed, what has been set 

 forth in this chapter gives anything like a true account oi 

 the relations existing between Voluntary and Automatic 

 Movements, not another word need here be said against 

 the general point of view upon which Hughlings Jackson 

 and Ferrier rest their hypothesis as to the existence of 

 'motor centres' in the Cerebral Cortex, nor against the 

 view that the mechanisms for Voluntary Movements are 

 ' organized ' in regions altogether apart from those con- 

 cerned with the execution of Automatic Movements. 



What has been said in the earlier parts of this chapter 

 in reference to the origin and nature of ' Volitional ' 

 stimuli, together with what has been stated above, make 

 it possible to explain the results of irritation and de- 

 struction of certain fronto-parietal areas of Grey Matter 

 and of the white matter intervening between them and 

 the Corpora Striata, without in the least countenancing 

 the supposition that ' motor centres ' exist in the Cerebral 

 Convolutions.* 



The Centres in question are rather 'sensory' in nature, 

 and are probably intimately concerned with certain groups 

 of Kinaesthetic Impressions whatever other functions 

 they may subserve, or with whatever other centres they 

 may be in intimate relation. We have, indeed, seen 



* We have here, in fact, to do with a misconception very simi- 

 lar in kind to that which previously led Foville and others to 

 regard the Cerebellum as a Sensory Organ (p. 504) simply because 

 ' internuncial fibres ' enter it from various sensory nuclei or ganglia. 

 To argue that groups of cells have motor functions, merely because 

 stimuli issuing from them evoke movements when they impinge 

 upon motor ganglia, is quite on a par with the argument that an 

 organ has sensory functions because fibres come to it from sensory 



