110 



ZOOLOGY. 



(6) The residue of the nerve after all these branches 

 have been given off, runs on either side of the oesophagus, 

 and ends in connexion with the solar plexus. 



17. Spinal Accessory Nerve. The 'eleventh nerve is 

 peculiar. It arises by the union of fibres from several of 

 the spinal nerves of the neck, as well as some from the 

 vagus, and can only get out of the skull by first running 



Fig. 59. RELATION OF VAGUS TO CHIEF 

 ARTERIES. 



A, in embryo Rabbit and adult Frog ; B, in 

 adult Rabbit. 



into it by the foramen magnum. It passes out by the 

 foramen lacerum posterius, and is distributed to some of 

 the neck muscles. 



18. Hypoglossal Nerve. The twelfth, hypoglossal nerve, 

 is equivalent probably to the ventral roots only of several 

 spinal nerves : it arises from the ventral surface of the 

 medulla, passes through the condylar foramen, and is dis- 

 tributed to the muscles of the tongue, being purely motor. 

 A small branch (ramv~<* descendens) goes to one of the 

 neck-muscles. 



