ix] Intcniiciliate Preceittral Area 223 



A third cerebral hemisphere which 1 have placed in the museum at Rainhill Asylum and 

 carefully examined is illustrative on the negative side of this question. The individual (a 

 middle-aged man) from whom it was taken, was twice an inmate of the institution named. 

 On his first admission he had complete motor aphasia; this, however, proved to be transitory 

 and he was discharged at the end of a few months recovered in all respects. He remained 

 out tor twelve years and then returned suffering from alcoholic insanity, but he now had no 

 speech defect nor had he been troubled all these years by a recurrence of the old disability. 

 He died suddenly from a perforated duodenal ulcer. At the autopsy an old-standing patch of 

 softening was found in the left hemisphere, and this we attributed to embolism, because there 

 were coexisting signs of old mitral endocarditis ; the distribution of the lesion was curious, the 

 lower two-thirds of the pars basilaris were completely destroyed, but on making a series of 

 horizontal sections we found that the destruction did not extend inwards beyond the plane 

 of the surface of the insula : it thus left the white substance anterior to the lenticular nucleus 

 and internal capsule destroyed in the other cases intact; some of the fronto-parietal 

 operculum further back, and a portion of the temporal operculum, and also some of the cortex 

 of the insula was obliterated, but the orbital operculum and the pars triangularis were quite 

 untouched. Now I am quite certain that anyone inspecting this specimen would at once say 

 that the individual must have suffered from permanent motor aphasia ; placed beside the two 

 hemispheres from cases of complete motor aphasia already alluded to, the area of destruction, 

 as seen from the surface, is quite correctly placed, and indeed more extensive. There being an 

 old-standing anatomical defect we are forced to assume that it was the cause of the transient 

 motor aphasia from which this person suffered earlier in life, and we are also compelled to accept 

 the illustration provided by the case on the striking difference in effect between a superficial 

 and a penetrating lesion. These were cases which came under my own observation ; many 

 others telling the same story could be cited from the records. 



Naturally, therefore, we must assume from clinical evidence that the cortex covering the 

 small area of Broca does not wholly repi-esent the seat of government of the motor element 

 in speech. 



Secondly, the inference which one derives from a complete histological study of the cortex 

 in this situation is that since the cortex of the inferior frontal convolution anterior to the pars 

 basilaris, and also that of the orbital operculum. is identical in structure with that of Broca's 

 field, and since also the presence of an abundance of intra-cortical association fibres is a character 

 common to these parts, therefore this anterior prolongation of the " intermediate precentral " 

 formation may share with the cortex of Broca's area the higher function of exciting the primary 

 oral, lingual, and laryngeal centres, lying more posteriorly, to the production of the complex 

 system of movements adequate to articulation. In accordance with this hypothesis, if speech is 

 to be abolished by a superficial lesion confined to cortex that lesion must affect the whole of 

 the combined area indicated. 



Thirdly, the reason which can be advanced to explain why a limited but penetrating 

 lesion in the area of Broca produces motor aphasia in its complete form is that the associations 

 between all this cortex and the direct oral, lingual, and laryngeal centres placed along the lower 

 end of the ascending frontal convolution suffer interruption. 



Unfortunately I am acquainted with no clinical evidence which can be advanced either 

 for or against the view that the speech area has the extended distribution here suggested, 

 although possibly such evidence may exist. A lesion strictly confined to the cortex only of the 



