ASSOCIATION AREAS OF FLECHSIG. 771 



that they connect either neighbouring or more distant parts of the 

 cortex. 



Most of the association fibres are comparatively short, but there 

 are some well-known long tracts of this description, such as the superior 

 longitudinal bundle passing between the Kolandic region and the 

 parieto-occipital region; the perpendicular bundle, passing between the 

 parietal lobule and the temporo-occipital region ; the anterior associa- 

 tion bundle connecting the frontal and temporal lobes and passing across 

 the bottom of the Sylvian fissure ; and the inferior association bundle 

 connecting the temporal and occipital lobes and the fibres of the fornix 

 and cingulum (see Fig. 352). 



According to Flechsig, the association fibres, which are both centrifugal 

 and centripetal, serve largely to connect the inexcitable or association 



FIG. 352. Diagram of the association fibres of the cerebral hemisphere, s., short 

 fibres, connecting adjacent gyri ; f.l.s., fasciculus longitudinalis superior; 

 f.l.i., fasciculus longitudinalis inferior; f.u., fasciculus uncinatus ; ci., 

 cingulum ; f.p., fasciculus perpendicularis ; fo., fornix ; fi., fimbria ; v.d'A., 

 bundle of Vicq d'Azyr. 



areas with the excitable or projection areas, and through them also the 

 various projection areas are indirectly interconnected and coagitated. 

 Flechsig regards, therefore, these inexcitable regions of the cortex as 

 constituting a great association centre, or rather three association centres, 

 which he designates respectively the frontal, the parieto-occipito- 

 temporal, and the insular centre, the chief function of these centres being 

 to associate together impressions received from the adjacent sensory or 

 projection areas. Dependent upon them is the due appreciation of the 

 impressions recorded upon the several parts of the sensory cortex, and he 

 also regards them as the seat of memory. 1 Hence their lesion, although 



1 The portions of the association areas which lie immediately adjacent to the excitable 

 areas (which latter, according to Flechsig, are really sensory) are termed by Flechsig ^the 

 " marginal zones." They receive from the excitable areas innumerable fibres of association, 

 and according to Flechsig are concerned especially with the memory of sensory impressions. 



