1886.] 1^ [Stowell. 



proximal third, and is distributed throughout the muscle ; it often com- 

 municates with the cervico- facial nerve about 10 mm. peripherad of its 

 origin. As it crosses the post-auricular artery it gives two or three fila- 

 ments to the sympalhic plexus around this blood-vessel. 



Cephalic Division of the Nerve-Trunk. — As the common trunk emerges 

 cephalad from the foramen of exit, it lies dorsad of the stylo- mastoid 

 artery (a small twig from the post-auricular), and crosses the lateral border 

 of the post-auricular artery ; at the dorsal border of the artery the trunk 

 divides into the cervico-facial and the temporo-facial rami. (In some in- 

 stances this trunk seems to give origin to the stylohyoid nerve.) 



N. cervico-facialis. — This is the cephalic and ventral ramus of the com- 

 mon trunk ; it is ectad of the carotid artery and the facial vein, entad ot 

 the submaxillary gland, and upon the ectal surface of the masseler 

 muscle. At the cephalic border of the submaxillary gland it divides into 

 three rami, the infra-maxillary, supra-maxillary and the buccal. 



The first brancli of the cervico-facial trunk is given off at the origin of 

 this nerve ; it lies ectad of the carotid arterj^ and is directed dorsad and 

 laterad upon the ectal surface of the parotid gland ; about 12 mm. from its 

 origin, ectad of Stenon's duct, it bifurcates, each division again branching 

 into two or four ramuli and terminating in the dermal muscle ectad ot the 

 gland (Platysma myoides). A few filaments may be traced to the zygo- 

 matic muscles. 



This branch receives a considerable accession from the temporo-facial 

 nerve near its origin ; some of the filaments seem to terminate in the sub- 

 stance of the parotid gland. 



5-8 mm. peripherad of the origin of the cervico-facial nerve a second 

 fascicle is sent to the zygomatic muscles. 



N. infra-maxillaris. — This is the ventral division of the cervico-facial 

 nerve ; it lies ectad of the facial artery and the facial vein ; 5 mm. periph- 

 erad of its origin it divides into several rarnuli which anastomose freely and 

 terminate upon the platysma. A large fascicle joins the superficial cer- 

 vical nerve from the cervical plexus. 



N, supra-maxillaris. — This is the middle division of the cervicofacial 

 nerve. (It often arises as a branch of ihe buccal nerve, given off at the; 

 border of the orbicular muscle at the angle of the mouth ; its distribution 

 is constant.) 



Its general course is toward the angle of the mouth ; it lies ectad of the 

 facial artery and vein ; it forms a dense plexus upon the ectal surface of 

 the ventral lip ; the ventral ramuli supply the muscle between the fora- 

 men mentale and the mandibular symphysis (M. depressor labii), and 

 anastomose with the mental branch of the mandibular division of the tri- 

 geminus nerve; .its filaments are also given to the orbicular muscle (M. 

 orbicularis oris). 



N. buccalis is the dorsal branch of the cervico-facial nerve ; it gives 

 several anastomotic filaments to the infra orbital branch of the tempuro- 

 tacial nerve ; it joins the plexus at the angle of the mouth (Plexus labi- 



