327 



teeth are level. (Figs. 56, 57, 58. 59, 60, 61, 62, and 



63). 



About ten years of age the upper firsts and thirds 



— the latter particularly — appear grooved. The 

 grooves are well marked, and run in a longitudinal 

 direction, in consequence of the shrinkage of the gums 

 from the teeth, and as the teeth wear and the gums 

 recede, the crowns grow nearer the grooves. There 

 are all also grooves on the inside walls of the firsts, 

 which correspond fairly to those on the outside. 

 When both are uniform the age of a horse is more 

 easily determined. From ten years of age to twenty- 

 one the horse will wear his teeth so fast away that the 

 crowns will touch the bottom of the grooves, so that, 

 in order to arrive at a correct conclusion of his age, a 

 calculation is necessary between ten and twenty-one. 

 When the grooves are half-way down the teeth the 

 horse will be about fifteen years of age, and when they 

 are intermediate on either side between the gums and 

 the crowns, i.e., quarter and three-quarters down, he 

 will be from twelve to thirteen, and from seventeen to 

 eighteen respectively. The grooves in the firsts and 

 thirds, along with the general formation of the teeth, 

 render it possible to arrive at Very accurate conclusions. 

 Generally speaking, the older a horse gets his teeth 

 assume a darker hue in consequence of discoloration 

 caused by ordinary wear, and sometimes by disease, 

 so that the colour of the teeth must always be carefully 

 considered in reckoning the age of a horse. (Figs. 64, 

 65, and 66). 



