610 THE CEREBRAL RELATIONS OF 



for their mistakes in writing — these may he detected at 

 once, or not till the occasion of some suhsequent perusal 

 of such writing. Persons who are liable to make such 

 mistakes in expression, may occasionally altogether wrongly 

 apprehend some word which they hear spoken or which 

 they see in writing or in print, in a way quite surprising 

 to themselves, when the mistake is recognized. 



■ 4. — Damage to Commissures hetiueen the Auditory and 

 the Visual Word- Centres. 



On reflection it will seem clear that there must be at 

 least two sets of commissures between the Auditory and 

 the Visual Word-Centres ; the one (a) for transmitting 

 stimuli from the Visual to the Auditory Centres {visuo- 

 auditory fibres), as in the act of reading aloud, or naming 

 at sight ; the other (b) for conveying impressions in the 

 opposite direction, i.e., from the Auditory to the Visual 

 Centre {audito-visual fibres), as in the act of writing from 

 dictation. 



Both sets of commissures may be simultaneously 

 damaged, and this seems to have been the cause of the 

 most notable defects met with in two of the writer's own 

 patients, whose cases are subjoined. The first of them 

 came under observation at the National Hospital for the 

 Paralysed and Epileptic, in 1869,* but nothing similar was 

 encountered until last summer, when the second exami)le 

 was seen. The writer is not aware that any other such 

 cases are on record. 



A middle-aged woman had an attack of right Hemiplegia wiih 

 pretty complete Aphasia in the early part of the year 1868. In the 

 course of some months she improved considerably, though she con- 

 tinued subject to 'fits' at intervals. After twelve months she wns 

 able to walk about with a little assistance, though she was still 



♦ " Paralysis from Brain Disease, 1875," p. 201. 



