PAROTID GLAND AND REGION. 25 



lar vein lie beneath the gland ; the external carotid, accom- 

 panied by several large veins, passes through its middle, 

 sending off numerous branches ; curving from behind for- 

 ward the facial nerve divides within its substance. Its 

 own vessels and nerves are derived from the external 

 carotid artery and the facial nerve. 



The examination of the parotid will demonstrate the danger, if 

 not the impossibility, of completely extirpating this body during 

 life ; even in the dead subject it will be found that it is a very nice 

 dissection to remove it neatly and properly. The scissors will be 

 found a useful instrument in this operation, which should be com- 

 menced from the external carotid ; the branches of this, many of 

 which are small, should all be saved, so that when the gland is 

 removed the artery shall be left with all its offsets. 



The MASSETER MUSCLE arises from both surfaces of the 

 zygoma and from the malar bone, and is inserted into the 

 outer surface of the coronoid process, ramus, and angle of 

 the inferior maxillar}^ bone. In shape it is quadrilateral; 

 externally it is covered by a strong shining aponeurosis 

 obscuring its muscular fibres, and which is not to be 

 removed. The direction of the superficial fibres of this 

 muscle is obliquely backward ; of its deeper fibres obliquely 

 forward. 



The TEMPORAL APONEUROSIS is a brilliant fibrous mem- 

 brane covering in, and at its upper part adherent to, the 

 temporal muscle : it is attached superiorly to the curved 

 line that limits the temporal fossa, and below to the 

 Z3'goma by two layers, between which there is a layer 

 of loose fat and cellular tissue. 



The TEMPORAL ARTERY ramifies upon the temporal 

 aponeurosis ; it is one of the terminal branches of the 

 external carotid, arising within the parotid gland, where 

 it gives off the transverse facial branch (p. 23). Ascending 

 upon the temporal fascia, just above the zygoma, it sends a 

 small branch, called the middle temporal, through the fascia 

 to the temporal muscle, and then divides into two branches, 

 anterior and posterior ; the anterior is distributed in a very 

 tortuous manner to the forehead, where it anastomoses with 

 the supra-orbital branch of the ophthalmic artery; the pos- 

 terior passes backward to the occiput, where it anastomoses 

 with the occipital artery. 



The temporal aponeurosis is to be incised around its edges and re- 

 moved ; the zygoma is to be cut through with a chisel just in front of 

 the ear, and the malar bone is to be sawed through in front of the mas- 

 3 



