494 THE FUNCTIONAL RELATIONS OF TEE 



that a great part of the ' pia mater ' on this right side formed a cysts 

 in which not a trace of cerebral matter remained. This membrane 

 constituted the upper wall of a large cavity, the floor of which 

 alone was formed by the Thalamus, the Corpus Striatum and all 

 the parts on a level with these two bodies. No nervous matter 

 existed, therefore, above the level of the great ganglia on the right 

 side — and yet Andral says: — "Get individu avait re^u de I'edu- 

 cation et en avait profite ; il avait une bonne memoire; sa parole 

 etait libre et facile; son intelligence etait celle du commun des 

 homnies." 



Cases of a similar character have been recorded by 

 Cruveilbier and others, and it is a remarkable fact that 

 there has been not only a preservation of such an amount 

 of Intellectual Power, as to have given the appearance, at 

 all events, of no loss in this direction, but that the special 

 modes of Sensibility (such as Sight and Hearing) have 

 not be^n abolished on either side — there has been no uni- 

 lateral Blindness or Deafness even although the greater 

 part of the opposite Hemisphere may have been destroyed. 

 This preservation of the special senses, in such cases, the 

 writer has elsewhere endeavoured to explain by an exten- 

 sion of Broadbent's hypothesis concerning the single or 

 double activity of ' motor ' centres, to the problem as to 

 the conditions regulating the single or combined activity 

 of the ' sensory ' centres.* 



These previously recorded cases of disease of the greater part of 

 one Hemisphere and preservation of the special Senses on both sides, 

 stand out in notable contrast with the more recently published cases 

 of lesion of the posterior third of the 'internal capsule' in which 

 Jlemi-anccthesia has been produced (see p. 489). In the latter class 

 of cases there is a limited lesion in the ' sensory ' region of the Cere- 

 bral Peduncle just before it comes into relation with the Thalamus; 

 whilst in the cases in which there is little or no impairment of 

 Sense on either side the lesion has mostly involved the frontal and 

 parietal regions of the Hemisphere above the level of the Thalamus 



* " Paralysis from Brain Disease," 1875, p. 106. 



