I 



HEAD AND NECK OF THE HORSE 65 



of the tongue as the deep lingual artery (a. profunda linguae), on the 

 lateral surface of the genio-glossal muscle. When the tongue is in the 

 normal position of rest, the deep lingual artery is wavy ; the undula- 

 tions being obliterated when the organ is protruded. 



The lingual artery (and its continuation, the deep lingual) gives 

 numerous branches to the muscles and mucous membrane of the tongue. 

 Some of these, supplying the posterior part of the dorsum and root, are 

 known as rami dorsales linguae. 



M. CHONDROGLOSSUS. — A bundle of muscular fibres may sometimes 

 be found between the hyo-glossal and genio-glossal muscles. The fibres 

 composing the bundle arise in the neighbourhood of the joint between 

 the great and small cornua of the hyoid bone, and run forwards in a 

 nearly horizontal direction, to be lost among the other muscular fibres 

 of the tongue. 



Dissection. — Reflect the stylo-liyoid and the posterior belly of the 

 digastric muscle. If the part of the great cornu of the hyoid bone that 

 lies between the origins of the stylo-pliaryngeal and stylo-glossal muscles 

 be cut away, a better view of certain muscles of the pharynx Avill be 

 obtained. 



M. CHONDROPHARYNGEUS. — The chondro-pharyngeal muscle arises 

 from the thyroid cornu of the hyoid bone near its junction with the 

 thyroid cartilage of the larynx, a few fibres springing from the lamina 

 of the cartilage itself Its fibres pass upwards and inwards in the wall 

 of the pharynx to end in the tendinous raphe that occurs in the middle 

 line. 



M. CERATOPHARYNGEUS. — The cerato-pharyngeal muscle is not 

 constant, and, when present, is small. In the form of a narrow bundle 

 of fibres, it arises from the medial surface of the great cornu of the hyoid 

 bone not far from its anterior end, and terminates in the pharyngeal 

 raphe underneath the preceding muscle. 



It should be noted that the chondro- and cerato-pharyngeal muscles 

 are sometimes described together under the common name of tn. 

 hyopharyngeus. 



M. THYREOPHARY'NGEUS. — The thyro-pharyngeal muscle is the 

 broadest of the constrictors of the pharynx. Its origin is from the 

 lateral surface of the lamina of the thyroid cartilage at and in the 

 neighbourhood of its oblique line. Most of the fibres of the muscle end 

 in the pharyngeal raphe ; but some of them join a tendinous septum 

 between this muscle and the crico-pharyngeal. 



M. CRICOPHARYNGEUS. — The crico-pharyngeal is the most posterior 

 of the constrictor muscles of the pharynx. The fibres composing it 



