THE WHITE MATTEE OF THE CEEEBEAL HEMISPHEEES. 649 



districts of gray cortex which may be far removed from each other. The better 

 known of these fasciculi are the following: (1) the uncinate bundle; (-2) the 

 cingulum; (3) the superior longitudinal bundle; (4) the inferior longitudinal; and 

 (5) the occipito-frontal. 



The fasciculus uncinatus is composed of fibres which arch over the stem of the 



Cavum septi pellucid i 

 Corpus callosum 



Cingulum 



Corpus callosum 



Lateral ventricle 



Lateral ventricle 



Internal 

 capsule 



3 ('Temporal 

 part 



R- 



Olfactory 

 part 



Caudate nucleus 



Fasciculus occipito- 

 frontalis [superior] 



Internal 

 capsule 



Putamen 



Fasciculus longi- 

 tudinalis superior 



Globus 

 pallidus 



Claustrum 



Superior 

 *" operculum 



Insula 



Fasciculus occipito 

 frontalis [inferior] 

 Temporal 

 operculum 



Anterior 

 commissure 



Fasciculus uncinatus 



FIG. 576. Two FRONTAL SECTIONS THROUGH THE CEREBRAL HEMISPHERES OF AN ORANG, 

 IN THE PLANE OF THE ANTERIOR COMMISSURE. 



A, Section through the left hemisphere in a plane a short distance behind B, which is a section through the 

 right hemisphere. The positions of the great longitudinal association tracts are indicated in red. 



lateral cerebral fissure and connect the frontal pole, and the orbital gyri of the 

 frontal lobe, with the anterior portion of the temporal lobe. 



The cingulum is a very well-marked and distinct band, which is closely associated 

 with the medial edge of the neopallium. Beginning in front, in the region of the 

 anterior perforated substance, it arches round the genu of the corpus callosum and 



FIG. 577. DIAGRAMS OF THE LEADING ASSOCIATION BUNDLES OF THE CEREBRAL HEMISPHERE. 

 (Founded on the drawings of Dejerine). 



A, Lateral aspect of hemisphere. B, Medial aspect of hemisphere. 



is carried backwards on the superior surface of this structure at the place where 

 its fibres pass into the callosal radiation. The cingulum, therefore, lies under 

 cover of the gyrus cinguli and stands in intimate relation to the white centre 

 of this gyrus (Fig. 559, p. 631). At the posterior end of the corpus callosum 

 the cingulum turns round the splenium and is carried forwards, in relation to 



