46 THE SURGICAL ANATOMY OF THE HORSE 



their nerve-supply from the glosso-pharyngeal nerve. Gustatory bodies 

 are also present on the organs of Mayer or the papilla? foliata?. 

 There are two of these, one on either side, and they are placed 

 immediately in front of the anterior pillars of the fauces. They 

 are elliptical in shape and the long axis of the ellipse measures about 

 half an inch. 



The structure of the tongue is best studied from a transverse section, 

 a representation of which is given in Plate XII. 



Such a section reveals the fact that the tongue is mainly made up of 

 muscular tissue. A median septum divides the organ into two sym- 

 metrical halves. Closely applied to the upper three-fourths of this 

 septum is a large flat muscle, which is the genio-hyo-glossus, and below 

 this the septum has applied to it the genio-hyoid muscle. Externally to 

 the genio-hyo-glossus is a small muscle termed the middle hyo-glossus, 

 and this is covered by a large muscle to which the name great hyo- 

 glossus is given. 



All the foregoing structures are encased laterally and inferiorly 

 by the mylo-hyoid muscle, and superiorly by the continuation on 

 to the organ of the mucous membrane of the mouth. 



Amputation of the Tongue 



In the operation of amputation of the tongue in this region it is thus 

 seen that the greatest care is necessary whilst severing the outer fourth 

 of the organ on each side, since this contains the lingual and hypo-glossal 

 nerves and the lingual artery. If the knife is used, this portion should 

 be cut through in layers, first the mylo-hyoid muscle, then the lingual 

 and twelfth nerves, and then very carefully through the great hyo- 

 glossus muscle, when the lingual artery will be exposed. This should 

 be seized and ligatured, and the remaining portion of the tongue 

 may be quickly severed. 



Frequently this operation is performed with the ecrasciir, in which 



