THE AGE OF THE HORSE. 53 



presented for inspection. When the whole of 

 the incisor teeth are grooved, this method 

 becomes comphcated. The groove extends about 

 a third of the way down by the time the 

 animal is fifteen or sixteen years of age ; two- 

 thirds at twenty years ; and the whole of the 

 way between twenty-five and thirty years. So 

 far, very little mention has been made of the 

 molar teeth as a medium for ascertaining age. For 

 ordinary purposes it is not necessary to refer to the 

 molars, but it may become expedient to do so. 

 At one year the fourth permanent molar is on a 

 level with the first, second and third molars, but 

 it is cut about nine months. At eighteen months 

 the fifth molar is on a level with the others, and 

 between three and a half and four years, the sixth 

 molar is level. The first, second and third tem- 

 porary molars have to be replaced, and the first 

 and second are replaced at two and a half years, 

 whereas the third one is replaced at three years, 

 making a complete permanent set of molar teeth. 

 The tusks are sharp at six years, but blunt 

 at seven. In some instances of abnormal den- 

 tition the upper row of incisor teeth completely 

 overlaps the lower ones, whereas in others, the 

 lower teeth project beyond the upper ones. The 



