236 SIR CHARLES BELL ON THE FACIAL NERVE. 



EXPLANATION OF PLATE XIV. 



Fig. 1, A, B, Section of the Crus cerebri. 



A, Motor column. 



B, Sensitive column. 



C, The Third Nerve, arising from both columns. 



D, E, Tractus opticus, passing round the motor column. 



Fig. 2, A, Section of right Crus cerebri. 



B, Distinct fasciculi of the Third Nerve, arising from the muscular column. 



C, Similar fasciculi of the nerve arising from the sensitive column. 



D, The union of the fasciculi in a dense ganglionic texture. 



Fig. 3, Represents the origins of the nerves from the Pons Varolii and Medulla Oblongata. 



5, The Fifth Nerve in its two portions. 



6, The Sixth pair ; the nerve of the right side unravelled. 

 P. D, 7, The Portio dura of the Seventh Nerve. 



P. M. 7, The Portio mollis. 



8, The Glosso-pharyngeal, Nervus vagus, and Spinal Accessory, forming the Eighth pair. 



9, The Lingualis. 



The foramina, both large and numerous, mark the provision for the entrance of blood- 

 vessels, from which we may deduce the vital importance of the nerves.* 



Fig. 4, An enlarged view of the roots of the Sixth, of the Portio dura or Facialis, and of the Glosso- 

 pharyngeal nerve. 



A, The Pyramidal body. 



B, Corpus olivare. 



* Consult the interesting paper by Sir Asihty Coofer on the obstruction of the Vertebral Arterv. 



