428 



FIBRES OF THE BRAIN. 



corpus striatum, and the fibres are now so extraordinarily multiplied 

 as to be capable of forming a large proportion of the hemispheres. 



Fig-. 142.* 



* The base of the brain, upon which several sections have been made, shew- 

 ing the distribution of the diverging fibres. 1. The medulla oblongata. 2. 

 One half of the pons Varolii. 3. The crus cerebri crossed by the optic nerve 

 (4), and spreading out into the hemisphere to form the corona radiata. 5. The 

 optic nerve near its origin ; the nerves about the crus cerebri and cerebelli are 

 the same as in the preceding figure. 6. The olfactory nerve. 7- The corpora 

 albicantia. On the right side a portion of the brain has been removed to shew 

 the distribution of the diverging fibres 8. The fibres of the corpus pyramidale 

 passing through the substance of the pons Varolii. 9- The fibres passing 

 through the thalamus opticus. 10. The fibres passing through the corpus 

 striatum. 11. Their distribution to the hemispheres. 12. The fifth nerve: its 

 two roots may be traced, the one forwards to the fibres of the corpus pyrami- 

 dale, the other backwards to the fasciculi teretes. 13. The fibres of the corpus 

 pyramidale which pass outwards with the corpus restiforme into the substance 

 of the cerebellum ; these are the arciform fibres of Solly. The fibres referred 

 to are those below the numeral, the numeral itself rests upon the corpus 

 olivare. 14. A section through one of the hemispheres of the cerebellum, 

 shewing the corpus rhomboideum in the centre of its white substance ; the 

 arbor vitse is also beautifully seen. 15. The opposite hemisphere of the cere- 

 bellum, 



