72 THE ORANGE COUNTY 



At the expiration of five or six weeks, the two next incisors 

 may be seen. At three months they will have overtaken the 

 central ones, and both pairs will have nearly attained their 

 natural level. A third grinder will then have appeared; and 

 a little before or after the eighth month, the third nipper, 

 above and below and on each side, will have protruded. The 

 colt will now have his full complement of front or cutting 

 teeth. 



These teeth are beautifully adapted to their purpose. 

 They have in front an elevated cutting edge of consider- 

 able sharpness. It is formed of enamel, a polished sub- 

 stance which covers the tooth, and is almost too hard to be 

 acted on by a file. This elevated edge is bent somewhat in- 

 wards, and over the tooth, so that there is a depression be- 

 hind it which gradually becomes stained by the food, and 

 constitutes what is called " the mark," in the mouth of the colt 

 or horse. 



This elevated edge of enamel, hard as it is, is gradually 

 worn down in the act of nipping and cutting the food; and 

 as it wears away, the hollow behind becomes diminished, and 

 is at length totally obliterated. By the degree in which this 

 mark is effaced, the horseman, not only with regard to the 

 first, but the permanent teeth, judges of the age of the ani- 

 mal. This obliteration begins to be manifest at a very early 

 age. At six months it is sufficiently evident in the four cen- 

 tral nippers. At a year and a half the mark will be very 

 faint in the central nippers, diminished in the other two, and 

 the surface of all of them will be flattened. 



At twelve months a fourth grinder protrudes, and a fifth 

 at the expiration of two years. 



These are all temporary teeth. They were only designed 

 to last during an early period of the life of the animal; and 

 when his jaws become considerably expanded, they give way 

 to another set, larger, firmer, and that will probably last dur- 

 ing life. The permanent teeth had been long growing in the 

 socket beneath the temporary ones, and had been pressing 

 upon their roots, and that pressure had caused an absorp- 

 tion of these roots, until at length they lost all hold and were 

 displaced. 



When the animal is about three years old, the central pair 

 of nippers, above and below, are thus removed, and two fresh 

 teeth, easily distinguishable from the first by their increased 

 size, make their appearance, so that a three-year-old colt is 

 easily recognized by these two new and enlarged central 

 nippers. 



