810 THE TOXGUE. 



which enter at its base and under surface, and attach it to other paits : 

 these are called the extrinsic muscles of the tongue, and have been elsewhere 

 described (pp. 185 186). Other bands of fibres 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 follow. 



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

 tudinal fibres, is placed on the upper surface of the tongue, immediately 

 beneath the mucous membrane, and is traceable from the apex of the organ 

 backwards to the hyoid bone. The individual fibres do not run the whole 

 of this distance, but are attached at intervals to the submucous 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 out- 

 wards. 



The lingualis inferior (lingualis mu c cle of Douglas, Albinus, <fec.) consists 

 of a rounded muscular baud, extending along the under surface of the 

 tongue from base to apex, and lying outside the genio-hyo-glossus between 

 that muscle and the hyo-glossus. Posteriorly, some of its fibres are lost in 

 the substance of the tongue, and others reach the hyoid bone. In front, 



Fig. 568. LONGITUDINAL VERTICAL SECTION OF THE TONGUE, LIP, &c. (from Kolliker 



and Arnold). 



m, symphysis of the lower jaw; tZ, incisor tooth ; h, hyoid bone ; g h, genio-hyoid 

 muscle; g, genio-hyo-glossus spreading into the whole extent of the tongue ; t r, trans- 

 verse muscle : Is, superior longitudinal muscle ; gl, lingual glands ; f, lingual follicles; c, 

 epiglottis ; I, section of the lip and labial glands ; o, cut fibres of the orbicularis oris ; 

 I m, levator menti. 



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 form together with" the inter- 

 mixed fat a considerable part of its substance. They are found in the in- 



