12 



SPECIAL HISTOLOGY. 



Fig. 171. 



between the transverse fibres of the genio-glossus (glosso-pha- 

 ryngeus), of the stylo-glossus, and of the transversus, at the root 

 of the tongue ; more carefully traced, however, it is found that 

 these, like the posterior portions of the genio-glossus, break up 

 into many lamella, which ascend, slightly curved, between the 

 transverse fibres, as far as the outer portions of the glandular 

 layer of the root of the tongue ; and finally, like the plates 

 of the genio-glossus, which lie internal to them, end in it. 

 Anteriorly the lingualis inferior unites with the larger bundles 

 of the stylo-glossus ; ending at the point of the tongue with 

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

 sends many delicate lamellae 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 backwards. 



Finally, there exist in man yet another longitudinalis, or 

 lingualis superior, and isolated perpendicular fibres. The longi- 

 tudinalis superior (figs. 169, 170, l.s, 171, e), 

 constitutes a longitudinally 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, separated 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; oc- 

 cupies, a little in front of the papillae circum- 

 vallatae, almost the entire half of the tongue, 

 and thence passes forwards in the form of 

 narrow bundles, united here and there at acute angles, im- 

 mediately under the mucous membrane, between the ends 



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

 a, papilla fungiformis ; b, papilla filiformis; c, mucous membrane; d, fibrous layer 

 below it; e, longitudinalis superior ; f, genio-glossus ; g, transversus, cut across. 



