648 THE CEREBRAL RELATIONS OF 



the Motor Centres, concerned with Speech-movements 

 and with Writing-movements, in the Corpus Striatum. 



The relation existing between the Auditory and Visual 

 Word-Centres and the parts of the Kinsesthetic Word- 

 Centres to which impressions derived from Speech-move- 

 ments and Writing- movements respectively proceed, are 

 confessedly uncertain. There is reason to believe, how- 

 ever, that the incitations which evoke Speech start 

 primarily from the Auditory Word- Centre, and then 

 pass through the corresponding Kin£esthetic Word-Centre, 

 so as to rouse it into conjoint and practically simultaneous 

 activity. Similarly, there is reason to believe that the 

 incitations which evoke Writing-movements start primarily 

 from the Visual Word- Centres, and thence pass through 

 the related parts of the Kinesthetic Word-Centres. 



It is clear, therefore, that destruction of the Auditory 

 and of the Visual Word- Centres would cause inability to 

 Speak and inability to Write. These disabilities w^ould, 

 however, be associated with such defects as have been 

 considered under the head of Amnesia — viz., inability to 

 comprehend Speech and Writing, together with inability 

 to revive Auditory and Visual ideas of Words. 



What w^e are specially concerned with in the present 

 section are the results that follow upon damage to the 

 outgoing fibres leading from the left Auditory and Visual 

 through the Kinsesthetic Word-Centres, to the great Motor 

 Ganglion beneath — viz., the Corpus Striatum. 



It would seem that these two sets of outgoing channels 

 are, at all events in some parts of their course, situated 

 moderately close together, so that they may be destroyed 

 simultaneously by some small lesion, and that too without 

 the implication of outgoing fibres for limb-movements — • 

 and consequently without the association of a right-sided 

 paralysis. One of the two cases originally described by 



