222 Management ajid Treatmejit of the Horse. 



large in comparison to the size of the jaw, and 

 occupy the whole front, as seen in Plate (Fig. 1), 

 in three weeks or a month the third grinders 

 make their appearance, and within six weeks an 

 additional incisor on each side of the first two 

 both above and below will be visible, and soon 

 after be completed and the jaw will have assumed 

 the form as seen in Fig. 2. The two molars that 

 the foal has at birth remain until the animal is 

 two and a half years of age, when they are forced 

 out of their sockets by the protrusion of the 

 second set, or replacers, as they are commonly 

 called; but from this time there is no use in 

 consulting the grinders as to age, though they 

 should be continually looked to for ragged edges, 

 which frequently cut the mouth and prevent their 

 feeding. After this age the best and easiest way 

 to come at it is by the incisors. 



The supplementary molars appear in the fol- 

 lowing manner, the first two at about ten months, 

 the second at about twenty months, and the 

 third at about from four to six years of age. 



The incisor teeth are continually undergoing 

 change in consequence of the friction produced 

 by the action of their rubbing against each other. 

 The anterior edge being considerably more ele- 

 vated and sharper than the posterior, the wear • 

 first commences there, and in a short time it is 

 level with the posterior, then both wear together. 

 The longitudinal cavity becomes narrower, and 

 afterwards triangular, and finally disappears, and 

 is replaced by the funnel next the root ; it is this 

 regular wear that is said ''loosing the mark.'' 



