ANIMAL DENTISTRY. 



145 



leaving the fissure oris free from obstruction. They have 

 the advantage also of opening the mouth to any w^idth de- 



j^i^Cl £m 



Fig. ioi. 



sired, and the disadvantages of being none too reliable. The 

 ratchet may break or slip when the jaws of a powerful horse 



Fig. 102. 

 are set against its strength. Slipping of the ratchet is a very 

 frequent accident after the catches have become worn from 

 constant use. 



