74 BITS AND BRIDLE GEAR. 



due in almost all cases, to its having been put on wrongly, or 

 to its faulty construction. Respecting these points, see pages 

 103 to 1 06, and 77 to 84. 



ACTION OF CURBS. 



When the reins of a curb are drawn tightly, the following 

 pressures are exerted in the manner shown by arrow-heads in 

 Fig. 91. 



1. On the bars of the lower jaw and on the tongue by the 

 mouth-piece. 



2. On the chin-groove, which is the smooth and rounded 



Fig. 92. View of under-surface of Lower Jaw. 



portion of bone on the under surface of the lower jaw, and 

 immediately in front of the bifurcation of the branches of that 

 jaw (Fig. 92). 



3. On the poll of the horse's head, over which the crown- 

 piece of the headstall passes. 



4. The pull of the reins. 



From the remarks already made about the principles of 

 bitting, and the action of snaffles, we may conclude that the 

 pressure of the mouth-piece is the only legitimate one for 

 restraining a horse. 



The pressure of the curb-chain on the chin-groove should 

 be rendered as little irksome to the animal as possible; because 



