IXTPJXSIC MUSCLES OF TOXGUE. 



331 



Fk. 23'2. 



Fig. 232. — Section op a Lymphoid Crypt frost 

 THE Root of the Tongue. 30 Diameters. 

 (Kolliker). 



a, epithelial lining ; 6, papillce of the mucous 

 membrane ; c, outer part of the crypt, formed 

 of connective tissue ; d, outlet, and e, cavity of tlie 

 crypt ; g, surrounding follicles. 



superjacent epithelium. Here and there the mucous membrane exhibits 

 recesses or crypts (fig. 232), 

 either simple or surrounded 

 by smaller ones which open 

 into them. The walls of 

 these recesses are generally 

 studded with lymphoid no- 

 dules ; and they receive 

 many of the ducts of the 

 raucous glands, 



B. — Muscular Sub- 

 stance. — The substance of 

 the tongue is chiefly com- 

 posed of muscular fibres 

 running in different but de- 

 terminate directions. Many 

 belong to muscles which 

 enter at its base and under 

 surface, and attach it to 

 other parts: these are called 

 the extrinsic muscles of the 

 tongue, and are elsewhere 

 described. Others which 

 constitute the intrinsic or proper muscles, and are placed entirely within 

 the substance of the organ, will be here more particularly noticed. 

 They are as follows : — 



The lingualis superficialis (noto-glossus,Zaglas), consisting mainly 

 of longitudinal fibres, is plated on the upper surface of the tongue, 

 immediately beneath the mi cous membrane, and is traceable from the 

 apex of the organ backArar<:s to the hyoid bone (figs. 233, 234, I s). 

 The individual fibres do not run the whole of this distance, but are 

 attached at intervals to the sub-mucous and glandular tissues. The 

 entire layer becomes thinner towards the base of the tongue, near 

 which it is overlapped at the sides by a thin plane of oblique or nearly 

 transverse fibres derived from the palato-glossus and hyo-glossus muscles. 

 According to Zaglas, the fibres of this muscle are directed forwards 

 and outwards. 



The lingualis inferior (lingualis muscle of Douglas, Albinus, and 

 others) consists of a rounded muscular band, extending along the under 

 surface of the tongue from base to apex, aud lying outside the genio- 

 hyo-glossus between that muscle and the hyo-glossus (fig. 234, li). Pos- 

 teriorly, some of its fibres are lost in the substance of the tongue, and 

 others reach the hyoid bone. In front, having first been joined, at the 

 anterior border of the hyo-glossus muscle, by fibres from the stylo- 

 glossus, it is prolonged beneath the border of the tongue as far as its 

 point. 



The transverse muscular fibres of the tongue (figs. 233, 234, t r) 

 form together with the intermixed fat a considerable part of its sub- 

 stance. They are found in the interval between the upper and lower 

 longitudinal muscles, and they are interwoven extensively with the other 

 muscular fibres. Passing outwards from the median plane, where they 

 take origin from a fibrous septum, they reach the dorsum and borders of 

 the tongue. In proceeding outwards, they separate, and the superior 



