270 



DIGESTIVE OEGANS. 



[sect. 130. 



the dorsum of the tongue downwards to the part where the genio- 

 glossi are lost in the lingual substance ; it does not, however, end 

 here with a sharp border, but is directly connected with the peri- 

 mysium between the two genio-glossi muscles. At either side of 

 this dissepiment, the genio-glossi spread out in a fan-shaped man- 

 ner into the tongue (fig. m), so that they occupy the middle of 

 the organ from the apex to the root, and form a long, moderately 

 broad, fleshy mass, which, however, is anything but compact. That 

 is to say, the genio-glossi, arrived in the tongue itself, divide on 

 either side, from the lower border of the lingual septum, where 

 some of their bundles decussate, into a large number of lamella;, 

 lying behind each other, which, at short distances from each other, 

 and separated by the transverse muscular fibres of the tongue, 

 run to the dorsum ; the most of them perpendicularly, but some 

 of them curved forwards or backwards. The fibres of the genio- 

 glossus, thus parted into separate lanrinse, which are on an average 

 o - o6'" to 0-14'" thick, extend as far the septum Ungues, and then 

 alter their relation, and generally in such a manner, that they now 

 form lamellae extending from before backwards. Whilst previously, 

 the genio-glossi were divided into transverse lamellae by the separate 

 layers of the transversus, they now become divided in the lon- 



Fig-ni. gitudinal direction, 



7i '- ">■ 9' by the interposition 



of bundles of the 

 longitudinal 



upper 

 muscle 



tongue. 



st.r/l. 



of the 

 These per- 

 pendicular and lon- 

 gitudinal laminae are 

 very distinct in the 

 two anterior thirds 

 of the tongue, less 

 so in the region of 

 the papillce circum- 

 vallatcB, where espe- 

 cially in the middle 

 of the tongue, the 

 genio - glossus ap- 

 proaches the mu- 

 cous membrane more in form of isolated fasciculi ; lastly they 

 are not all demonstrable at the root of the tongue. The genio- 

 glossus terminates at the upper surface of the tongue, by its 



Transverse section of the human tongue, a little in front of the 

 papilla; circumvallatce ; g. genio-glozsus ; li. longiludinalis infe- 

 rior (lingualis) with the arteria ranina ; ir. transvtrsus, visible 

 in its whole extent on the right side, on the left only at the edge 

 and between the divaricating bundles of the genio-glossus; g. ter- 

 mination of the genio-glossus upon the mucous membrane ; h. ter- 

 mina ion of the hyo-glossus ; Is. longitudinal^ superior with fiat 

 bundles interposed between the perpendicular fibres; d. glands of 

 the margin of the tongue ; st. gl. stylo-glossus. 



