206 A MANUAL OF ANATOMY. 



Within the skull the ninth nerve gives off minute men- 

 ingeal twigs to the dura and arachnoid. 



Within the jugular foramen arises from the petrous gang- 

 lion the nerve of Jacobson, (which passes to the tym- 

 panum), communicating branches to the superior cervical 

 ganglion of the sympathetic, to the pneumogastric, and to 

 the lingual branch of the facial. 



10. The Pneumog-astric Nerve. Figs. 53, 10, u 

 As given above and described on page 103. 



u. The Spinal Accessory. Figs. 53, 10, n. 



The accessory portion has been given with the glosso- 

 pharyngeal ; the spinal part arises from the anterolateral 

 surface of the cord as low as the fifth or sixth cervical ver- 

 tebra. These filaments pass upward, uniting to form a 

 single trunk, which enters the skull through the foramen 

 magnum ; then, being joined by the accessory portion, the 

 nerve passes out from the skull as above given along with 

 the ninth and tenth nerves through the central division of 

 the jugular foramen. See page 91. 



12. The Hypoglossal Nerve. Figs. 53, 10, 1 1. 



The superficial origin of this nerve is from the groove 

 between the olivary body and the anterior pyramids of the 

 medulla. The nerve is in the shape of two portions, which 

 do not become joined until they enter the anterior condy- 

 loid foramen, through which the nerve leaves the skull. 

 See page 88. 



(Within the foramen a recurrent meningeal twig is given 

 off to the dura.) 



(The deep origin of the nerve is from a long nucleus 

 internal to that for the ninth, tenth, and eleventh nerves, 

 close to and parallel with the median line in the floor of 



