CIRCULATORY SYSTEM. 191 



with an inclination forward and downward, crossing the buccina- 

 tor muscle a little in advance of the anterior border of the nias- 

 seter. Having run as high as the level of the bony ridge from 

 which the masseter arises, it detaches a large branch, and then 

 winds upward and spreads into an arborescent expansion upon 

 the upper and fore part of the face. a. It mostly sends one or 

 two masseter branches backward, h. Buccal twigs from both 

 sides, c. The superior labia/, the branch whose origin has just 

 been shewn, takes its course below the false nostril, to which it 

 sends ramifications, to the upper lip, wherein it anastomoses with 

 the terminating branches of the palatine arteries and also with its 

 fellow, d. Long slender branches, commonly two, to the false 

 nostrils, e. Terminating ramifications to the cellular substance 

 and skin covering the fore part of the face, which anastomose 

 with others making their exit from the infra-orbitar foramen, and 

 also with some straggling twigs escaping from the cavity of the 

 orbit. 



2. The parotideal branches are those we may consider 

 next to the submaxillary branch of the external carotid. They are 

 too variable in number, size, and mode of origin to admit of spe- 

 cial description : they come off as the vessel continues its course 

 under the gland. 



S. A large branch, internally, to the pterygoideus. 



4. One much longer, externally, the posterior masseter artery. 



5. The posterior auricular commonly comes off from 

 the external carotid immediately opposite to the last -mentioned 

 branch. It emerges from underneath the parotid gland, and as- 

 cends in a direct line to the back of the concha of the ear, where 

 it splits into three divisions, which thence proceed along its dor- 

 sum to its tip, distributing branches right and left; and these 

 anastomose freely with one another, and likewise with the other 

 auricular arteries, and thereby form a beautiful vascular net-work. 

 It also gives branches to the parotid gland, to the muscles of the 

 concha, the meatus auditorius externus, and membrana tympani. 



6. The temporal artery, the anterior auricular, and the 

 internal maxillarij, may be considered as the terminating branches 

 of the external carotid. The temporal leaves the trunk just as it 

 is issuing from the depth of the parotid gland, and then curves 

 upward and forward around the neck of the jaw, a little below 

 the condyle, which serves as a guide to cut down upon it; from 

 this, it runs in a straight line towards the outer circumference of 

 the orbit, opposite to which margin it dips into the substance of 

 the masseter, and so eludes further trace without the aid of dis- 

 section. We find it henceforward corresponding in course to the 

 line of the maxillary ridge, sending branches down into the 



