THE CORTEX OF THE FORE-BRAIN, ETC. 



71 



prine between two neighboring regions of the cortex by teasing. 

 The representation of the connections existing between more 

 widely separated regions is much more difficult, and the figures 

 must he at least partly diagrammatic, not representing the actual 

 course of fibres. A few bundles only can be easily discerned. 

 Such are the fasciculus uncinatus, the fasciculus arcuatus, the 

 fasciculus longitudinalis inferior, the cingulum, and a few more. 

 You may see the course of these bundles in the accompanying 



diagram. 



Among these larger association-bundles there are few 



that contain very long fibres. They consist rather of numerous 

 shorter fibres, which run in the same direction, each covering a 

 certain part of the whole dis- 

 tance to be traveled. These fibres, 

 which connect the different parts 

 of one hemisphere with each 

 other, are mixed with fibres which 

 connect the corresponding por- 

 tions of the two opposite hemi- 

 spheres. These latter fibres run 

 almost exclusively in the corpus 

 callosum and the anterior com- 

 missure, thus passing transversely 

 through both hemispheres, from 

 one to the other. 



Inasmuch as you are probably acquainted with the general 

 macroscopic appearance of the corpus callosum, at least that 

 portion of it which is distinct from other parts of the brain. I 

 shall have only a few words to say concerning the accompanying 

 Fig. 41. 



You must keep in mind that, just as you see the fibres 

 pas>ing t from side to side in this section, which is made about 

 transversely through the chiasm, so they are to be seen in the 

 whole region of the brain over the lateral ventricles. Fibres 

 also pass into the corpus callosum from the anterior and pos- 

 terior regions. The course of the fibres cf the corpus callosum, 



FIG. 41. 



Frontal section through the fore-brain. 

 Diagram of tho .course of the corpus eal- 

 kisuui and the anterior commissure. 



