704 



OP THE FUNCTIONS OP THE NERVOUS SYSTEM. 



parent that this is not merely the representative of the proper Optic G-anglion of 

 Man, but also of the Thalamus Options; whilst, again, the mass which is desig- 

 nated as the Cerebral lobe (B) is chiefly homologous with the Corpus Striatum 

 of higher animals. The nature of the latter body is made apparent in the higher 

 Cartilaginous Fishes, by the presence of a ventricle in its interior ; the floor of 

 this cavity being formed by the Corpus Striatum, whilst the thin layer of 

 nervous matter which forms its roof is the only representative of the Cerebral 



[Fig. 189*. 



A. Dissection of a brain which had been hardened in spirits of -wine. It represents the base of the 

 brain with the course of the fibres from the pyramidal or motor columns, on the left side expdled con- 

 tinuously from the pyramidal body (T), through the pons Varolii (x), which has been partly removed on that 

 side, forming (u) the under part of the crus cerebri, plunging to the corpus striatuin (M), emerging (mm mm) 

 from thence, and running forwards, forwards and outwards, outwards and backwards, to the whole extent of 

 the hemispherical ganglion (B B B). The course of some of the fibres of the superior longitudinal commissure, 

 and also some of the fibres of the great commissure, are shown. B B B. Convoluted surface of the brain, or 

 hemispherical ganglion. K. Thalamus optici divided. L N, L N. Anterior cornua of the lateral ventricle 

 separated by N, septum lucidum. M M. Corpora striata. N. Anterior pillars of the fornix running from the 

 c a, corpora albicantia. p p. Posterior extremity and under surface of the great transverse commissure, or 

 corpus callosum. p p. Fibres continued to the posterior lobe. A p. Anterior extremity of ditto. 8. Corpus 

 olivare. T. Corpus pyrarnidale. u u. Crura cerebri. w w. Corpus restiforme. x x. Pons Varolii ; a?, divided 

 end of it, where it enters the cerebellum, a c. Anterior commissure, divided a little to the right of the 

 mesial line. g. Groove in the corpus striatum, from which it has been removed, c. Third pair of nerves. 

 /*,/*. Fissura Sylvii. h n. Descending fibres of the fornix over the hippocampal convolution. 1 ED.] 



1 ["Solly oil the Brain," Am. Ed.} 



