26 ANATOMY OP THE HEAD AND NECK. 



seter muscle; this muscle being partially detached from the surface 

 of the ramus of the jaw, and turned downward with the portion of 

 the zygoma and malar bone, and a layer of fat and soft cellular tissue 

 removed, the whole temporal muscle will be exposed. 



The TEMPORAL MUSCLE arises from the temporal aponeu- 

 rosis and from the surface of the depression on the side of 

 the skull known as the temporal fossa. Its fibres converge 

 to form a strong, flat tendon, which is inserted into all the 

 inner surface of the coronoid process of the inferior maxil- 

 lary bone, from its apex to near the last molar tooth. 



DISSECTION III. 



DURA MATER AND SINUSES. 



The removal of the calvaria may be accomplished by breaking 

 through the skull on a line just above the frontal sinuses and tlie 

 tops of the ears, with the sharp part of a French hammer, or it may 

 be done more neatly with a saw, the track for which has been marked 

 out by the aid of a string tied round the head. The saw is to be carried 

 through the outer table of the bone only, and the inner one fractured 

 by a chisel and mallet ; this saves the membranes of the brain from 

 being wounded, but does not leave the bones in so neat a condition 

 for preservation, when that is desired. The sensation communicated 

 to the hand by the saw, and the color of the bone-dust, tell the ope- 

 rator when he has got through the outer table and reached the vascular 

 diploe between the two tables. The application of very considerable 

 force will be required, by either prying or pulling with a hook or 

 chisel introduced into the line of the incision, to effect the detachment 

 of the calvaria from the membranes adherent to it. 



The DURA MATER is the most external of the cerebral 

 membranes; it acts as periosteum to the bones of the skull 

 and as a support to the brain ; it is rough externally, where 

 it is torn from the calvaria, and especially so along the line 

 of the sutures ; parts of it are occasionally left adhering 

 to the detached calvaria. Upon its surface along the 

 median line some small fibrous bodies, called PaccJiionian 

 glands, will be noticed ; they are wanting in infancy and 

 most numerous in old age ; depressions in the bone corres- 

 ponding to them will sometimes be found. 



The dura mater should be cut with scissors along the 

 margin of the sawed skull except at the median line in 

 front and behind. The two flaps thus formed may be 

 turned up on to the top of the brain. It will now be seen 



