ORIGIN AND DISTRIBUTION OF THE NERVES. 131 



cavernous sinus, on through the foramen lacerum-orbitale. 

 In entering the cavity, the nerve divides into two branches. 

 The smaller is generally received by the levator oculi. The 

 larger branch subdivides into several others ; the longest of 

 these runs round the eyeball, and penetrates the oblique mus- 

 cle. Two or three others run to the abductor and depressor 

 muscles. 



Fourth pair of pathetic. These take a filamentous origin, 

 and pass the border of the tentorium, entering the cavernous 

 sinus, from thence to the orbit. Its destination is the supe- 

 rior oblique muscle of the eye. 



Fifth pair, or par trigeminum. These are the largest nerves 

 of the brain. They take their origin by filaments from the 

 crura cerebelli, and pierce the dura mater. Each nerve ap- 

 pears to form a ganglion ; from this ganglion, we say that 

 three nerves depart : one is called the ophthalmic ; the second, 

 the anterior maxillary ; the third is the posterior maxillary 

 nerve. The ophthalmic nerve is the smallest of the three 

 divisions ; as it emerges from the orbit, it divides into three 

 branches, called the lachrymal, the super-orbitar, and the 

 lateral nasal branch. 



The second division, or anterior maxillary nerve, leaves the 

 cranium through the hole, called foramen rotundum, of the 

 sphenoid bone, and takes its passage through the inferior orbi- 

 tal canal, whence it emerges, covered by the levator labii 

 superior, upon the face ; here it splits into several large 

 branches, denominated the facial nerves. But prior to its 

 entering this canal, it detaches several important branches to 

 the eyelid, lachrymal duct ; aj^o several long filaments which 

 descend on the tuberosity of the anterior maxilla, penetrate 

 the bone, and furnish twigs to the antrum, and the two supe- 

 rior molar teeth. The largest branch is the spheno-palatine, 

 or lateral nasal nerve, to which the foramen spheno-palatine 

 gives passage into the nose, wherein it divides into two sets 

 of filaments. One of these is spread over the lateral parietes 

 of the nasal cavity ; the other ramifies over the sinuses, and 

 sends a filament to the lower border of the septum. A branch 



