TKEPHINING. 



285 



trejyhine, or trepan, in various modified forms. There are also 

 others which may be considered as accessory, viz., scissors, bis- 

 touries, forcejis, bone-scrapers and elevators. 



The brace and bit trephine is the orio-inal instrument which 

 has been more or less modified, and which, while it is capable of 

 more rapid execution, is probably less controllable than the ordin- 



FiG. ■,TO.— Bichat'8 Trephine. 



Fig. 293.-01d-Fa8hioned Trephine. 



Fig. 300.— Single-Handed Trephine. 



