THE TONGUE. 



443 



deeper, very firm layer of the mucous membrane, to be described pre- 

 sently, and partly run as far as the bases of the papillce. At the root 

 of the tongue, the genio-glossus does not reach so far as the mucous 

 membrane, which may here be easily dissected away, with its mucous 

 sacs, from the more deeply situated racemose glands, but ends upon and 

 between the latter, uniting with them, or with a dense fibrous tissue 

 between them, by means of tendinous striae. 



The transverse muscle or the transverse fibres of the tongue (trans- 

 versus linguce sive fibrce transversales, Pig. 169, tr., 170, tr., 171, g\ 

 consists of very numerous lamellae belonging to each half of the tongue, 

 which penetrate with great 

 regularity between the 

 transverse lamellce of the 

 genio-glossus, and are to 

 be found in all sections of 

 the organ. Each lamella 

 is 0-1-0-16 of a line thick, 

 and in the middle of the 

 tongue f ths of a line deep ; 

 it is usually perpendicu- 

 lar and its muscular fibres 

 extend from the septum 

 linguce to the lateral bor- 

 der of the tongue. They arise, so to say, directly from the whole surface 

 of the septum, by the intermediation of a small quantity of a transverse 

 tendinous tissue, distinct from its longitudinal fibres, and pass, united 

 into small flat bundles, at first, directly outwards. In their further 

 course, they curve upwards, and finally, the uppermost shortest fibres 

 reach the sides of the dorsum of the tongue, the inferior longer ones, 

 its proper lateral margin, where they also become attached to the 

 mucous membrane by means of short bands of connective tissue. The 

 other lingual muscles form, in a manner, the sheath of the organ and, 

 in their course, partly follow the above, partly take their own special 

 direction. 



The hyo-glossus (baseo- and cerato-glossus of authors), has, at the 

 sides of the tongue, nearly the same relations as the genio-glossus, in 

 the middle. Its coarser bundles, in fact, break up when they have 



FIG. 170. Transverse section of the human tongue, a little in front of the papilla circumval- 

 lata: g, genio-glossus ; Li, longitudinalis inferior (hngualis) with the arteria ranina ; tr, trans- 

 versus, visible in its whole extent on the left side, on the right only at the edge and between 

 the divaricating bundles of the genio-glossus ;'g, termination of the genio-glossus upon the 

 mucous membrane ; /i, termination of the hyo-glossus ; Is, longitudinalis superior, with flat 

 bundles interposed between the perpendicular fibres ; rf, glands of the margin of the tongue ; 

 st.gl, stylo- glossus. 



