52 ANTHROPOLOGY. 



gold process of the palate Done ; it fills the greater part of the pterygoid 

 fossa, and is inserted into the inner side of the angle of the jaw. Its use is 

 to draw forward and elevate the jaw, and to rotate it. 



Pterygoideus externus arises from the outer side of the external pterygoid 

 plate, from the crest on the root of the great wing of the sphenoid, and 

 from the back part of the tuberosity of the superior maxilla ; it is inserted 

 into the anterior and internal part of the neck of the lower jaw, into the 

 inter-articular cartilage, and into the inferior synovial membrane. Its use 

 is to draw forward the jaw with the inter-articular cartilages : when both 

 muscles act alternately, they become the principal agents in grinding the 

 food. 



PI. 127, fig. 1, superficial muscles of the head from the left side : \ epi- 

 cranial aponeurosis; ''^, occipito-fron talis, anterior portion; \ posterior 

 portion, the two connected by the epicranial aponeurosis ; ", attollens aurem ; 

 *, retrahens aurem ; ', attrahens aurem ; *, orbicularis palpebrarum ; *, com- 

 pressor naris ; ", levator labii superioris alajque nasi ; ", levator labii supe- 

 rioris ; '", zj^gomaticus minor ; ", zygomaticus major ; ", levator anguli 

 oris ; '^, depressor anguli oris ; '°, depressor labii inferioris ; ", levator 

 menti ; ", orbicularis oris ; '°, buccinator ; ''°, masseter. 



Fig. 2, deep-seated muscles of the head from the left side : ', temporal 

 muscle ; ", corrugator supercilii ; ', superior oblique muscle of the eye ; *, 

 levator palpebree ; ^, compressor naris ; °, depressor naris ; ', orbicularis ; ', 

 levator anguli oris ; ", depressor labii inferioris ; ", buccinator. 



PL 124, ß^. 15 ', epicranial aponeurosis ; *, occipito-frontalis ; *, com- 

 pressor naris ; *, levator labii superioris alaeque nasi ; *, levator proprius 

 labii superioris ; ", orbicularis ; ', depressor anguli oris ; ', depressor labii 

 superioris; ', transversus menti (of rare occurrence); ", attollens aurem; 

 ", attrahens aurem ; ", orbicularis palpebrarum ; ", zygomaticus major ; 

 ", zygomaticus minor. 



Fig. 16 \ occipital portion of occipito-frontalis ; "^^ retrahens aurem. 



Fig. 17', occipital portion of occipito-frontalis. 



PI. 125, fig. 19 ', temporalis ; ^, levator palpebrae superioris ; ', zygoma- 

 ticus ; \ orbicularis ; °, levator anguli oris ; \ masseter. 



Fig. 20 ', temporal muscle. 



PI. 126, fig. 20', orbicularis; ', buccinator; ^, levator menti. 



B. Muscles of the Neck. 



The neck is that contracted portion of the trunk between the head and 

 chest, the cervical vertebrae forming its skeleton or support. Its anatomy 

 is very intricate, containing numerous muscles, nerves, and vessels, besides 

 the pharynx, oesophagus, larynx, and trachea. The muscles on the back of 

 the neck will be considered with those of the back of the trunk. We shall 

 confine ourselves to those of the anterior and sides. 



The muscles of the anterior part of the neck are very numerous, and are 



concerned in the performance of various functions. Some act as muscles 



of locomotion, others are engaged in deglutition, in respiration, and in the 



exercise of voice and speech. They are symmetrical or similar on each 



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