THE CBANIAL OR ENCEFEALIC NERVES, 



843 



series of branches analogous to those of the gustatory nerve, and which mix 



with them. , , ^ • 



These branches are therefore reflected upwards, bendmg round the posterior 



Fig. 459. 



DEEP NERVES OF THE HEAD IN THE MULE. 



1 Superior maxillary nerve at its exit from the foramen lacerum ; 2, masseteric nerve; 3, sub- 

 ' zygomatic nerve ; 4, buccal ; 5, lingual or gustatory nerve ; 6, chorda tympani ; 7, inferior 

 maxillary nerve, cut near where it enters the maxillo-dental canal; 8, mylo-hyoideus nerve 



maxiuary ueive, uui. ncai «iicic ii, c.cio x..^ ............ ..., „„....., _,..._,-. -j -■_ ,. 



pterygoid nerve; 10, glosso-pharyngeal nerve; 11, its pharyngeal branch; 12, its lingual branch; 

 13, pneumogastric nerve; 14, superior laryngeal branch of that nerve; 15, its pharyngeal 

 branch; 16, spinal accessory of Willis; 17, hypoglossal nerve; 18, origin of the cervical cord of 

 the great sympathetic; 19, the same after its union with the pneumogastric. A, Common 

 carotid artei-y ; B, accessory thyroid artery ; C, thyro-laryngeal artery ; D, origin of the internal 

 carotid artery (the vessel is concealed by the guttural pouch) ; E, occipital artery ; F, external 

 carotid artery; G, internal maxillary artery; JI, pharyngeal artery (drawn too large); /, sub- 

 maxillary artery; J, lingual artery; A', origin of the maxillo-muscular artery; L, posterior 

 auricular artery ; M, trunk or origin of the superficial temporal artery ; 0, inferior dental artery ; 

 F. posterior deep temporal artery; Q, anterior deep temporal artery; ^, maxillary gland; S, 

 Wharton's duct ; T, sublingual gland. The letter N placed at the upper end of the large cornu 

 of the hyoid bone has no signification. 



border of the great hyo-glossus, and pass into the interstice between that muscle 

 and the genio-glossus. They are distributed to all the muscles of the tongue. 



The hypoglossals, being motor nerves, cause the contraction of the muscles 

 of the tongue during the movements proper to mastication and the production 

 of the voice. Though they most frequently act together, yet they may do so 

 separately, as in the unilateral movements of the tongue. 



Differential Characters in the Cranial Nerves of the other Animals. 



In the domesticated Mammals, the cranial nerves offer the greatest analogies; their origin 

 is the same in all, and it is only in their distribution that we find some variety, due to the 



