ANTERIOR ASPECT OF HEAD AND NECK. 



face of the Hyo-glossus and Genio-hyoglossus; and lateral 

 nasal, an inconstant gland in the angle between the cheek and 

 ala of the nose. An infraorbital and a malar gland are de- 

 scribed. [910] 



Those of the neck are as follows: superficial cervical, lying 

 over and at the posterior border of the Sterno-mastoid, along 

 the external jugular; submaxillary , around that gland; supra- 

 hyoid, lying on the Mylo-hyoid below the chin ; post-pharyngeal, 

 lying behind the pharynx, on the two upper vertebrae; pre- 

 laryngeal, lying in front of the larynx, between the Crico- 

 thyroids; pre-tracheal, lying on the front of the trachea; and 

 deep cervical, lying along the internal jugular and extending 

 outward along the subclavian vein in two groups, upper and 

 lower, respectively above and below the bifurcation of the 

 carotid artery. [911] 



THE MOUTH AND PHARYNX. 



Mouth. The aperture is bounded by the lips. The vesti- 

 bule is the space between the lips and cheeks externally, and 

 the teeth and gums internally. The cavity lies within the 

 dental arches and has a roof and floor; it opens behind into 

 the pharynx, through the isthmus of the fauces. [995] 



Teeth. There are eight in each half of either jaw, arranged 

 from before backward as follows: Two incisors, central and 

 lateral, with chisel-shaped crowns and single roots. One ca- 

 nine, with a conical crown and a long, single root. Two pre- 

 molars (bicuspids), first and second, with two cusps in the 

 crowns; the roots are either single or partly divided. Three 

 molars, first, second, and third, with from three to five cusps 

 on the crowns; the lower ones have doubled roots, and the 

 upper ones tripled roots. [1014] 



Tongue. The body consists of a cortical portion, chiefly 

 longitudinal fibres, surrounding a central (medullary) portion; 

 the latter is divided into lateral halves by a median fibrous 

 septum and is mainly formed by vertical and transverse fibres. 



[85] 



