8 OPERATIVE TECHNIQUE. 



which a wooden rod is thrust. This is apphed to the hind hmb, about 

 four to six inches above the hock, and is tightened by twisting the rod. 



It being impossible to apply the ordinary cord twitch to the ox, a 

 kind of forceps is used, which grasps the lower section of the nasal 

 septum. The bull-holder, as this is called (Fig. 8), is provided with 

 loops at the free ends of the handles, by means of which it can be 

 secured to the animal's horns. In the bull-holder shown in Fig. g 

 pressure is applied by means of a screw. 



Nose-rings may here be mentioned ; the most convenient are those 

 which can be inserted without the assistance of an instrument. 

 Hauptner's pattern (Fig. lo) is very practical. It consists of two semi- 

 circular pieces connected by a hinge ; one end is pointed and cutting, 

 for the purpose of transfixing the nasal septum ; this fits into a corre- 



FiG. 6. — The loop twitch. 



Fig. 7. — The loop-twitch tightened by 

 inserting: a wooden rod. 



sponding depression in the other end, and is provided with a notch to 

 receive the spring catch shown in the figure. Figs. 11 and 12 represent 

 leaders for animals in which these rings have been inserted. 



To means of restraint also belong gags — instruments for holding apart 

 the jaws to allow of examining or operating on the cavity of the mouth 

 or pharynx without danger of being bitten. Some are fixed, others mov- 

 able, the latter allowing the mouth to be more or less opened as desired. 

 One of the simplest forms of fixed gag consists of a heart-shaped piece 

 of iron with two transverse branches fixed about four inches apart. 

 It is thrust into the mouth horizontally until the upper cross-piece 

 comes in contact with the upper molars, and then rotated so that the 

 upper cross-piece remains in contact with the interdental space and 

 the animal's chin lies in the lower rounded space. Movable gags are 



