Fibres of the Brain. 



121 



Fasciculi 

 -pyramid. 



465. The Fibres of the Truncus CerebrL* 



View from below. Natural size. 



The fibres of the posterior column of the cord are con- 

 tinued partly into the restiform bodies, partly into the tegmentum ; 

 those of the lateral column are grouped into three bundles, of which 

 the posterior helps to form the restiform body, while the middle forms 

 the Funlculus tares, and together with the Cms cerebelli ad cerebrum (ad 

 Corpus quadrigeminum) the base of the tegmentum, and the anterior becomes 

 the pyramid. The anterior column is continued to form the olivary 

 body, and, forming the Lemniscus, runs to the Corpus quadrigeminum. 



Some of the diverging fibres end in the cerebral ganglia, while 

 others pass through and receive additional fibres from them, and, as they 

 emerge, radiate into the anterior, middle and posterior lobes of the hemi- 

 spheres ; these fibres are called Corona radiata. The commissural fibres or 

 commissures connect the hemispheres with each other, different parts of 

 the same hemisphere and the cerebellum with the cerebrum. Such commis- 

 sures are: between the cerebral hemispheres the Corpus callosum, the 

 anterior and posterior commissures in the third ventricle; between the 

 hemispheres of the cerebellum the Pons Varolii, and vermiform pro- 

 cess; between cerebrum and cerebellum the Crura cerebelli ad Corpora quadri- 

 gemina ; between Corpus quadrigeminum, tegmentum and optic thalamus 

 the Bracliium antlcum et postlcum of the Corpus quadrigeminum. 



* See note, page 122. 



