THE NECK. 169 



liyoides gives off tlie submaxillary artery, wliicL, running 

 between the long cornu and hyoideus inagnus,.gives off the 

 .lingual artery running forwards, and then meets with and 

 accompanies the corresponding vein, and the parotid duct 

 over the internal surface of the inferior margin of mas- 

 seter internus. After reaching the external part of the 

 dilated superior extremity of the long cornu, the external 

 carotid gives off large posterior masseter Iranches anteriorly, 

 parotid branches and branches to stylo-maxillaris exter- 

 nally, and the posterior auricular posteriorly. This 

 latter branch gives off the middle auricular, which runs 

 to the external auditory opening. The external carotid is 

 here covered by the mucous membrane of the guttural 

 pouch, a transparent layer which covers both sides of the 

 long cornu of os hyoides ; on reaching the temporo- 

 maxillary joint the artery terminates in three branches, the 

 anterior auricular, which runs to the front of the ear to 

 supply the structures in that neighbourhood ; the tem- 

 poral, which winds round the jaw and runs along the 

 superior margin of masseter externus ; and the internal 

 maxillary, which runs to the base of the cranium. 



The levator humeri must now be dissected to its attach- 

 ment to the crest of the occiput ; to the mastoid ridge ex- 

 tending downwards laterally from that ridge, the wing of 

 the atlas by a tendon common to it and trachelo-mas- 

 toideus and splenius, the transverse processes of the second, 

 third, and sometimes fourth cervical vertebrae. By turning 

 up its inferior margin we show the branches of the cervical 

 intervertebral nerves running directly to it. Its attachment 

 to the superior margin of the ligamentum nuchse by f aschia, 

 and its blending posteriorly with trapezius may also be 

 noticed ; by this time its attachments to the fore limb will 

 be shown, i. e. to the spine of the scapula, the point of the 

 shoulder, the humeral ridge with its elongating ligament, 

 and the antero-uiferior depression of the humerus. 



By removal of levator humeri we expose a second layer 

 -of superior cervical muscles. Eunning from the transverse 

 processes of the cervical vertebrae, as far forwards as the 

 third to the superior margin of the scapula is serratus 

 magnus, and from the antero- superior angle of the scapula 

 rhomboideus runs in the form of an extremely elongated 

 triangle to within six inches of the attachment of the 

 •cordiform portion of the ligamentum nuchae to the occiput. 



