THE TONGUE 435 



thinner than in front, and there it is overlapped by the trans- 

 verse fibres of the hyo-glossus, and is intermixed with the 

 fibres of the chondro-glossus. 



Musculi Longitudinales Inferiors. The inferior longi- 

 tudinal muscles are two rounded fleshy bundles placed upon 

 the inferior aspect of the tongue, one on each side. Pos- 

 teriorly, each inferior longitudinal muscle lies in the interval 

 between the hyo-glossus and the genio - glossus, and is 

 attached to the hyoid bone ; anteriorly, it is prolonged 

 to the apex of the tongue between the medial border of 

 the stylo-glossus and the genio-glossus ; with the former it is 

 more or less blended. 



Musculus Transversus Lingua. The fibres of this muscle 



Superior longitudinal 

 ; muscle 



j-Lamellae of 



f transverse muscle 



Genio-glossu's ^Inferior longitudinal 



Genio-hyoid \ |tl 



Hyoid bone 



FIG. 172. Longitudinal section through the Tongue. 

 (From Aeby. ) 



lie under the superior longitudinal fibres, and constitute a 

 thick layer which extends laterally from the lateral face of 

 the septum linguae, to the side of the tongue. The fibres 

 of the genio-glossus ascend through this transverse stratum 

 and break it up into numerous lamellae (Fig. 172). It is 

 joined by the fibres of the palato-glossus (Henle) (Fig. 171). 



Musculus Verticalis Lingua. The vertical fibres extend in 

 a curved direction from the dorsum to the under aspect of 

 the tongue, and decussate with the fibres of the transverse 

 muscle. 



Nerves and Vessels of the Tongue. The nerves of the 

 tongue are (i) the glosso-pharyngeal; (2) the lingual; (3) 

 the hypoglossal; and (4) a few twigs from the internal 

 laryngeal. These should be traced on the left side of the 

 tongue, where the mucous membrane is still in position. 



The glosso-pharyngeal nerve has been traced up to the point 



