Chap, xix.] THE CEREBRO-SPINAL GANGLIA. 163 



which is, however, doubted by many observers, and 

 on the other into the crusta of the cms cerebri. 



217. The internal capsule is one of the most 

 important masses of white matter ; it contains the 

 tracts of medullated nerve-fibres which pass between 

 the white matter of the cerebral hemisphere and the 

 crus cerebri i.e., the corona radiata of Reil ; further, 

 it contains tracts of medullated nerve-fibres passing 

 between the thalamus opticus and the white matter 

 of the cerebral hemispheres ; and, finally, it contains 

 tracts of nerve-fibres passing between the corpus 

 sfcriatum and the crus cerebri. 



218. The pineal fland, or conarium, and the 

 anterior lobe of the hypophisis cerebri, are epithelial 

 in structure and origin, and will be described in a 

 future chapter. The pineal gland contains a large 

 amount of calcareous matter brainsand. 



The corpora albicantia are masses of white 

 matter i.e., medullated nerve-fibres; each corpus 

 albicans includes a centre of grey substance. 



The infundibulum and tuber cinereum at the floor 

 of the third ventricle are composed of grey matter ; 

 the latter extends between the corpora albicantia 

 to the optic commissure, while the former is connected 

 with the posterior or minor lobe of the hypophisis. 



CHAPTER XIX. 



THE CEREBRO-SPINAL GANGLIA. 



219. THE ganglia connected with the posterior 

 roots of the spinal nerves, and with some of the 

 roots of the cerebral nerves e.g., Gasserian, otic, 

 geniculate, ciliary, Meckel's ganglion, the ganglia of 



