ON THE FUNCTIONS OF THE CEREBRUM 323 



and-writing individuals visual association, and in others auditory 

 association, is the more natural method of acquisition. 



Language, therefore, as the instrument of thought, or even as 

 its compeer, for the higher refinements of thought depend so 

 entirely on, and draw so much of their inspiration from, the 

 possession of a highly elaborate vocabulary, is of fundamental 

 importance for the performance of the higher, as of the less 

 complex, psychic functions. 



Language, according to the type of sensorial or sensori-motor 

 avenues through which it is acquired and stored, and by means of 

 which it is employed, possesses four chief physical bases in the 

 cerebral cortex, namely, the auditory, visual, cheirographic, and 

 articulatory. For the sake of simplicity no attempt is made to 

 separate the kinaesthetic from the purely motor divisions of the 

 latter two, though, in fact, it may be regarded as certain that these 

 are differently located. The kineGsthetic divisions, are, however, 

 those which are at present under reference. All these " word- 

 centres " naturally lie in or near the auditory, visual, and general 

 sensory projection spheres of the cortex, as words merely constitute 

 one variety of sensorial impression. It might therefore be sup- 

 posed that loss of any one of the four afferent avenues to these 

 physical bases of language would not, owing to the commissural 

 connections between the several spheres, be of serious import, 

 apart from the non-reception oi sensations through the absent 

 channel. That such a view is incorrect can, however, readily be 

 demonstrated. The spheres referred to, with their commissural 

 connections and their afferent and efferent projection systems, 

 merely form a convenient mechanism for the mechanical acquisi- 

 tion and reproduction of language, which would be meaningless 

 unless during the employment of its mechanism there occurred 

 an active associational participation on the part of practically the 

 whole mantle of the cerebrum. 



A word, per se, represents merely an auditory or visual sensation, 

 or a cheirographic or articulatory kineesthetic impression, unless 

 it is employed as a symbol on which to integrate the percept or 

 concept which it signifies ; and for this the cerebral mechanisms 

 or associational systems connecting the different projection and 

 sensori-memorial regions of the cortex are needed. 



Further, both these developed percepts and concepts, and 

 also the associational processes involved in their formation, differ 



