'////; ASSOCIATION ///;/,'/>' <>1'' Till-: HEMISPHERES 



867 



company with the grey masses with which they arc concerned. They may be 

 summarised as follows: 



(1) Those of short course, the fibrse propriae, which associate contiguous gyri 

 with each ol her. These loop around the bottoms of t he sulci. cont inually receiving 

 and losing fibres in the cortex they connect. The stripes of Haillargcr within the 

 cortical layer might he included among the >hort association bundles. 



(2) The cingulum (girdle) lies in the gyrus cinguli and is shaped correspond- 

 ingly. It extends from the anterior perforated substance and the subcallosal gyru.H 

 around the gemi of the ecu-pus callosum, then, under cover of the gyrus cinguli and 

 around the spleniurn, and thence downwards and forwards in the hippocampal 

 gyrus to the nncus. It is chiefly an aggregation of fibres of short course fibres 

 which associate neighbouring portions of the cortical subMance beneath which they 

 course, and which, by continually overlapping each other, form the bundle. 



(3) The uncinate fasciculus is a hook-shaped bundle which connects the uncus 

 and anterior portion of the temporal lobe with the basal portion of the frontal lobe, 



Fio. 645. SCHEMATIC REPRESENTATION OF CERTAIN OF THE ASSOCIATION PATHWAYS OF THE 



CEREBRAL HEMISPHERE. 



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 INAL FASCICULUS 

 STRIA 77-.V.M//.V.IA/.V 

 OF Til ALA Ml .V 



CINGULUM 



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 J-'.isrn i i.i .s 



1M I l:HJR LONGITUDINAL FASCICULUS 



i.e., the frontal pole with the orbital gyri. Its shape is due to its having to curve 



backwards around the stem of the lateral cerebral fissure. 



(4) The superior longitudinal fasciculus is the longest of the association paths, 

 and connects the frontal, occipital, and temporal lobes. From the frontal lobe it 



passes laterally, transverse to the radiations of the corpus callosum and the lower 

 part of the corona radiata. along the inner aspect of theopercula, and above the in- 

 stila to the region of the posterior end of the lateral fissure, and thence it curves down- 

 wards and forwards to tiie cortex of the temporal lobe. Some of its fibres extend to 

 t he cortex of the temporal pole. The occipital portion consists of a loose bundle given 

 off from the region of the downward curve, which radiates thence to the occipital 

 cortex. 



(.")) The inferior longitudinal fasciculus connects the temporal and occipital 

 lobes and extends along the whole length of these lobes parallel with their tentorial 

 surfaces. Posteriorly it courses lateral to the lower part of the occipito-t halainic 

 radiation, from which it differs by the fact that its fibres are less compactly arranged. 



(6) The medial and lateral longitudinal striae of the upper surface of the corpus 



