140 



HUMAN PHYSIOLOGY. 



columns of the cord and medulla oblongata ; passing upward through the 

 crura cerebri, they receive accessory fibres from the olivary fasciculus, cor- 

 pora quadrigemina and cerebellum. Some of the fibres terminate in the 

 optic thalami and corpora striata, while others radiate into the anterior 

 middle and posterior lobes of the cerebrum. 



2. The transverse commissural fibres connect together the two hemi- 

 spheres, through the corpus callosum and anterior and posterior commis- 

 sures. 



3. The longitudinal commissural fibres connect together different parts 

 of the same hemisphere. 



FIG. 15. 



* c B 



po 



DIAGRAM SHOWING FISSURES AND CONVOLUTIONS ON MESIAL ASPECT OF THE RIGHT 

 HEMISPHERE. 



Median aspect of the right hemisphere. CC, corpus callosum divided longitudinally : 

 Gf, gyrus fornicatus ; H, gyms hippocampi; h, sulcus hippocampi; TJ, uncinate 

 gyms ; cm, calloso-marginal fissure ; F, first frontal convolution ; c, terminal portion 

 of fissure of Rolando ; A, ascending frontal ; B, ascending parietal convolution and 

 paracentral lobule; PI', praecuneus or quadrate lobule; Oz, cuneus ; Po, parieto- 

 occipital fissure; o\, transverse occipital fissure; oc, calcarine fissure; oc' , superior, 

 oc" , inferior ramus of the same ; D, gyrus descendens ; T4, gyrus occipito-temporalis 

 lateralis (lobulus fusiformis) ; T 5 , gyrus occipito-temporalis medialis (lobulus lin- 

 gualis). 



Functions. The cerebral hemispheres are the centres of the nervous 

 system through which are manifested all the phenomena of the mind; 

 they are the centres in which impressions are registered, and reproduced 

 subsequently as ideas ; they are the seat of intelligence, reason and will. 



