CHAP, xxvi.] VOLUNTARY MOVEMENTS. 579 



The statements made in paragraphs (2) and (3), though 

 they may be perfectly true, lend no special support to the 

 doctrine of Hughlings Jackson and of Ferrier. They are 

 equally or even more in accord with the views expressed in 

 this chapter. The damage or removal of parts of the Brain 

 concerned to a large extent with the Intellectual direction 

 of Movements, of parts which are accustomed in the most 

 direct manner to call into activity the Corpora Striata (the 

 great motor ganglia of the Hemispheres), would necessarily 

 interfere with the performance of each of such Movements 

 precisely in proportion to the need for intellectual guidance 

 in order to ensure its execution. The destruction of such 

 cortical areas, in fact, puts the Corpora Striata themselves 

 out of court, for the execution of all Movements except 

 those which are at once simple and 'automatic.' Hence 

 it is that the facts above cited lend no exclusive support 

 whatever to the notion that ' motor centres ' exist in the 

 Cerebral Convolutions. 



In the following paragraphs Ferrier sets forth certain 

 developments or corollaries from his doctrine. 



(4.) " The dog from which the cortical motor centres alone have 

 been removed is, however, in a very different position. It retains 

 its sensory centres, and is a conscious sentient animal, and is 

 capable of ideation and emotion. It is not merely a mechanism, 

 the activity of which is dependent purely on external stimulation, 

 but has within itself the springs of action in the mediate form of 

 revived or ideal impressions, and is thus capable of spontaneous 

 action. As, however, the revived impressions occupy the tsame 

 place, or coincide with the physiological activity of the same parts 

 as are engaged in the consciousness of present impressions, the 

 revived impressions can throw the automatic apparatus of move- 

 ment into action just as well as immediate or present impressions " 

 (p. 214). 



(5.) " In the dog deprived of its cortical centres the path from 

 impression to action is not, as in the ordinary course of volition, 

 through the cortical motor centres to the Corpus Striatum, and 



p p 2 



