162 ',* MYOLOGY. 



from the arlgle of the iliaxilla, and a portion is inserted to the 

 orbicular muscle of the mouth, forming the Retractor anguli oris 

 '(Risorius Santorini). Posteriorly it unites with the cervical por- 

 tion, which is likewise chiefly aponeurotic, comm^cing in^ "front 

 of the neck by' a thin muscular band, it joins itp fellow in the 

 median line by a. fibrous raphe, and covers the ^^muscles of the 

 inferior cervical region. Above it becomes aponeurotic, and is 

 \attached to the ligamentum nuchse, while iiifero-laterally it 

 becomes more fle^iy, and is inserted to the mteHor pq|tion of 

 the cariniform cartilage ; some describe thJs= |i^rtion as ^^krt of 

 the Levator humeri, the panniculus being firml^f blended with 

 that muscle inferiorly. The thoracic portion is colitinuoUs with 

 the cervjcal,. at the sternum, and passes over thfe front of the 

 ♦shoulder superiorly, covering its external side; it is attached to 

 the dorsal spines together with the trapezius. The abdominal 

 - portion forriis' a -broad oval-shaped lleshy expansion, its fibres 

 rtinnihg from" tlie flank to the shoulder; it is thick and flesh}^ 

 behind the arm, where it has a well-rnarked, flat tendinous attach- 

 ment to 4he skin, and below which a tendinous expansion pene- 

 trates between the chest and the 'limb, and is. attaelred to the 

 Pectoralis i^agnus and internal trochanter of the humerus. 

 Posteriorly, by.a strong band, fleshy and ^apojie orotic, it reaches 

 the stifle joint and fascia of th^ thi^h ; above, it ^reaches the 

 lumbar and dorsal spines; and below it betomes "blended with the 

 abdominal fascia: - ,' '^ ' \» ^' 



■'■' Relation^ — It is i:elated externally with thq skin ; intefnally 

 with the sup#ficial layer of muscles. - --- "'T.- 



Action., — .Jt corrugates the skin, and' thus enables tlie animal 

 to expel insects and irritating bodies, its use being thus protec- 

 tive ; to some extent it also supports and binds down the subja- 

 cent muscles. 



The Head. * 



The muscles of this region may be divided into the following 

 groups : Anterior maxillary. 



Posterior maxillary. . 



Hyoidean. 



Palpebral. . -- ^ \ 



Auricular. ' . .- ; 



In addition to these we h^ve tlie Glogs^l,"lP'haryngeal, ^nd 

 Laryngeal groups also associated with the head> the two first>of 



