REMOVAL OF THE SRAm. 433 



especially desirable to preserve the mesal surface of one hemisphere and the parts upon 

 the meson, the plane of section may be 1-3 mm. laterad (usually sinistrad) of the meson. 

 The lateral incisor will be destroyed unless previously removed; but the rest of the skull 

 will be unharmed, and its meson will be available for study. 



§ 1115. Instrumeints and Materials. — The same as for the 

 method first described (§ 1099), with the exception of the nippers, 

 and with the addition of the small back saw (§ 152) and the macro- 

 tome (Appendix). 



§ 1116. Decapitation.— RemoYQ the skin as directed in § 1101 ; 

 if the skin is to be mounted, divide it only from the dextral angle 

 of the mouth. 



With the arthrotome divide the M. temporalis along the dorsal 

 margin of the zygoma and the caudal margin of the orbital process 

 of the 0. malare, and dissect up the muscle for 1-2 cm. 



This will expose the end of the Pre. coronoideus of the mandi- 

 ble ; cut about it so as to free it from muscular and tendinous 

 attachments. 



Separate the masseter (Fig. 67) from the ventral border of the 

 zygoma, cutting to the Pre. coronoideus. At a point nearly mid- 

 way between the meatus aud. and the orbital process of the malar 

 is situated the Arthron temporo-mandibulare ; determine its exact 

 position by pressing with the finger whUe the mandible is moved in 

 various directions. Open the arthron as directed in § 1101. 



Ventriduct the mandible and cut any remaining attachments ; 

 then proceed as directed in § 1101. 



§ 1117. Mesal Hemisection. — With the arthrotome cut between 

 the two mesal incisor teeth and between the nasal bones ; also upon 

 the meson at the Crista lamhdoidalis and the caudal border of the 

 0. hasioccipitale. 



Adjust the slide so that when the head is forcibly pressed against 

 it the cuts just made coincide with the slit and groove of the macro- 

 tome. Rest the head with the canine teeth in the rebate, hold the 

 saw obliquely so that it runs in the slit and cuts through the facial 

 region. Then hold the saw more nearly horizontal ; finally, place 

 the skull flat upon the board and complete the hemisection with 

 long, steady strokes. 



§ 1118. Lateral Hemisection.— 1i it is desirable that the meson 



should be absolutely uninjured, remove a mesal incisor, and make 



the initial guiding cuts through the periosteum about 1 mm. laterad 



of the meson, so that the saw may pass through the vacant socket 



28 



