676 PROBLEMS IN REGARD TO LOCALIZATION OF 



Many cases are on record in which a lesion of the 

 posterior part of the third frontal gyrus of the right 

 Hemisphere has existed, without producing any loss of 

 Speech. So that we have both positive and negative 

 evidence in favour of Broca's association of the power 

 of Articulate Speech with the integrity of the third left 

 frontal convolution, especially if we extend the depth of 

 the region cited by him so as to make it include the 

 outgoing fibres from this part of the third frontal gyrus. 



FIG. 184. Brain of a Woman who suffered from Aphasia, showing the traeeb ef 

 a lesion in the posterior part of the third frontal Convolution. (Prevost.)-<SV<! 

 "Nature," March 16, 1876, p. 400. 



It is, however, also true that in a certain small pro- 

 portion of cases a similar condition of speechlessness has 

 been induced where a lesion has been found in the corre- 

 sponding parts of the right Hemisphere. In some of 

 these exceptional cases the persons have been left-handed, 

 though in others even this reason for the change of 

 sides has been absent. The writer has himself met with 

 a most typical instance of this. But it is of importance 

 to note that even in these very exceptional cases, though 

 the side affected has been different, Speech has equally 



