134 



HAND-BOOK OF PHYSIOLOGY. 



Functions of other Parts of the Brain. Of the physiology of the 

 other parts of the brain, little or nothing can be said. 



Of the offices of the corpus callosum., or great transverse and oblique 

 commissure of the brain, nothing positive is known. But instances in 

 which it was absent, or very deficient, either without any evident mental 

 defect, or with only such as might be ascribed to coincident affections of 

 other parts, make it probable that the office which is commonly assigned 



FIG. 345. View of the corpus callosum from above. U. The upper surface of the corpus cal- 

 losum has been fully exposed by separating the cerebral hemispheres and throwing them to the side ; 

 the gyrus formcatus has been detached, and the transverse fibres of the corpus callosum traced for 

 some Distance into the cerebral^ medullary ^substance. 1, the upper surface of the corpus callosum; 



formed by the 

 corpus cal- 



---- 7 -i ------- ~- ~~ ~*. ~j ^ . . t vi-. . .. * ^ 'i . w^.vt v_, ^vowii^j. j'.<i i vj- cxic liicioo wj_ imjj. co 



from the corpus callosum; 9, margin of the swelling; 10, anterior part of the convolution of the cor- 

 pus callosum; 11, hem or band of union of this convolution; 12, internal convolutions of the parietal 

 lobe: 13, upper surface of the cerebellum. (Sappey after Foville.) 



to it, of enabling the two sides of the brain to act in concord, is exercised 

 only in the highest acts of which the mind is capable. And this view is 

 confirmed by the very late period of its development, and by its very rudi- 

 mentary condition (Flower) in all but the placental Mammalia. 



To the fornix and other commissures no special function can be 

 assigned; but it is a reasonable hypothesis that they connect the action 

 of the parts between which they are severally placed. 



