THE TONGUE. 



445 



Fig. 171. 



them, and also, applying itself anteriorly to the hyo-glossm, it sends 

 many delicate lamellce between the transverse muscles as far as the 

 dorsum of the tongue, presenting, in fact, at the border of the anterior 

 third of the tongue, the same relations as the hyo-glossus further back- 

 wards. 



Finally, there exist in man yet another longitudinalis, or lingualis 

 superior, and isolated perpendicular fibres. The longitudinalis superior 

 (Figs. 169, 170, Is, 171, e), constitutes a longitudi- 

 nally fibrous layer placed between the uppermost fibres 

 of the transversus and the mucous membrane, which 

 occupies the whole breadth and length of the tongue 

 and proceeds from the chondro-glossus (overlooked by 

 most anatomists), which arises from the smaller cornu 

 of the hyoid bone as a moderately large bundle, sepa- 

 rated from the baseo- and cerato-glossus by the lingual 

 artery and the glosso-pharyngeal nerve. It passes 

 forwards, under the deep glandular layer of the root 

 of the tongue, and in part through the midst of the 

 termination of the genio-glossus and lingualis inferior; 

 occupies, a little in front of the papillce circumvallatce y 

 almost the entire half of the tongue, and thence passes 

 forwards in the form of narrow bundles, united here 

 and there at acute angles, immediately under the mu- 

 cous membrane, between the ends of the genio-glossi 

 and hyo-glossi, as far as the point of the tongue, here to 

 become lost in the integument on its upper surface. 

 Since these longitudinal fibres become thicker anteriorly, it is probable 

 that independent, superior longitudinal fibres, arising from the mucous 

 membrane of the dorsum of the tongue, and ending upon it, become 

 associated with them. I find perpendicular fibres, which do notarise 

 from without, only in the apex of the tongue, where delicate bundles of 

 them are stretched between the upper and lower layers of mucous 

 membrane. 



The lamellae of the most anterior part of the transversus pass be- 

 tween the inner portions of these bundles, whilst between their extre- 

 mities the longitudinalis superior and inferior and stylo-glossus pene- 

 trate with tolerable regularity, so that transverse sections exhibit an 

 alternation of perpendicular and longitudinal fibres, such as that which 

 appears in the dorsal part of the tongue in Fig. 170. 



It remains to be added, that the palato-glossus muscle becomes in 

 part lost, together with the cerato-glossus, in the mucous membrane of 



FIG. 171 Portion of a longitudinal section through the side of the human tongue: a, 

 papilla fungi for mis ; 6, papilla filiformis ; c, mucous membrane ; d, fibrous layer below it j 

 e, longitudinulis superior f, genio-glossus ; g, transversus, cut across. 



