BOOK IX. 



PART IT. 



Special Anatomy of the Nerves. 



CHAPTER I. 



OF THE NERVES OF THE ENCEPHALON. 



SECT. 1. 



THE course and distribution of the first pair, or the olfactory 

 nerves, have been described fully in the account of the brain 

 and nose. 



SECT. II. NERVUS OPTICUS. 



The Optic Nerve, as mentioned in the account of the basis 

 of the brain, gets into the orbit by the optic foramen, and is 

 there entirely surrounded by the origins of the muscles of the 

 eyeball. It then describes a slight curvature, of which the con- 

 vexity is outwards, and runs forwards for an inch, when it pe- 

 netrates into the ball of the eye, where it gives origin to or ex- 

 pands into the retina. Between the muscles and it, except at 

 their origins, there is a mass of adipose matter.. 



