Dissection of Sheep^s Head. 219 



across the ramus of the jaw, about an inch and a quarter 

 from its lower margin. 2, in a sloping direction across the 

 anterior part of the body of one jaw, about two inches from 

 the teeth and symphysis respectively, posterior to the mental 

 foramen; and 3, a similar cut in the same direction and 

 situation on the other jaw. Then, taking a scalpel, he should 

 scrape away the muscular attachments, &c., along the margin 

 of that jaw the ramus of which has been fractured, and con- 

 tinue the same operation on the inner surface of the jaw, 

 removing as far as possible the periosteum at the same time, 

 so as to avoid cutting any structures internal to it ; pressing 

 the bone away with the thumb of the left hand, and following 

 close to the bone with the scalpel in the right hand. The saw 

 will have cut through the Inferior dental nerve (mentioned 

 above), just as it has penetrated the substance of the Inferior 

 Maxilla to pass forwards in the dental canal beneath the 

 teeth; and again, just before its appearance on the outside of 

 the jaw at the mental foramen. This nerve being the second 

 branch of the Inferior Maxillary division of the Fifth Nerve 

 we have seen ; the first being the Auriculo Temporal branch 

 distributed on the face. 



Examination of Body of Jav^. The Student will do 

 well now to follow the Dental Nerve in the canal contained 

 within the maxilla. This may be accomplished by taking a. 

 chisel and mallet, and making a fracture along the inner side 

 of the anterior two- thirds of the jaw, and then placing the 

 chisel just under the upper edge of the fracture, chipping the 

 bone away towards the teeth and gums along their entire 

 course. By removing this inner plate of bone the implanta- 

 tion of the molars will be well seen ; and generally, at the 

 age a sheep is killed for food, a sac will be disclosed contain- 

 ing a molar tooth in process of formation, posterior to the 

 last molar visible through the gum ; as also three more 

 sacs with teeth, beneath the three anterior teeth that have 



