94 Dr. H. C. Bastian. On the Relations of Sensory [May 2, 



FlG. 2. Diagram illustrating relative Positions of four Cerebral Centres 

 concerned with Beading aloud. 



BMC 



VC, visual centre; z, visuo-auditory cummissural fibres. Other references as in 



Fig. 1. 



such desire is accompanied by a " conception " of the movement to be 

 performed. This " conception," in physiological terms, means a 

 revival in sub-conscious memory of the visual and kinsesthetic 

 impressions pertaining to the movement in question. 



Limb movements, like others, may be paralysed either by organic 

 lesions or by functional defects. 



A. Organic Lesions. 



If the kinaesthetic centres in relation with the limb are destroyed, 

 paralysis of the limb results, together with loss of muscular sense 

 and kinaesthetic impressions generally. This has now been deter- 

 mined by clinico-pathological evidence, as well as by the results 

 following excision of portions of the cortex by reason of disease 

 occurring therein. 



As yet we have no evidence from man of paralysis of limb move- 

 ments following extensive disease of the visual centre, or of the 

 commissures existing between it and the kina3sthetic centreis for the 

 limbs, comparable with the paralysis of speech movements following 

 disease of the auditory centre or the audito-kinsesthetic commissural 

 fibres, except in the case of writing movements. It is, however, 

 certainly true that with destruction of the left visual word-centre 

 the individual is no longer able to write words or even a single 

 letter. 



But it would seem that some experimental evidence on lower 



