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STUDIES IN LIFE AND SENSE. 



to them, but they are absolutely speechless, and cannot utter a single 

 word. It is a perfectly well-ascertained fact that aphasia, as a rule, 

 is associated with disease of Brocas' convolution, the front part of the 

 left half or hemisphere of the brain a part which may therefore be 

 called the " speech centre," and which is figured 9 and 10 in the 

 illustrations of man's brain (figs. 27 and 28). The curious fact must 

 thus be emphasised, that aphasia is almost invariably associated with 

 disease of the left (9 and 10), and rarely with disease of the right side 



FIG. 28. FERRIER'S CENTRES ON HUMAN BRAIN (viewed from above). 



of the brain. It is a noteworthy fact in brain-physiology, that when 

 an animal has been rendered blind by the destruction of the sight- 

 centre of one side, blindness disappears and sight gradually returns, 

 since the remaining and normal sight-centre of the opposite side 



