50 ILLUSTRATED STOCK DOCTOR. 



hooks are seated alone, over each corner tooth, but nearer to the cornef 

 teeth of the upper than those of the lower, so that they, (the hooks), 

 never come iu contact with each other. 



The horse has always attained the age of four and a half or five years 

 before he has a full number of perfect teeth. Before this time, th« 

 younger the animal the fewer the teeth, and even these are not all perma- 

 nent. 



The more a permanent incisor loses m length, by friction, the more it 

 also loses in width, so that the nearer the friction surface approaches to 

 the root, the narrower and thicker it must appear. 



Every new hook tooth is cylindrical and somewhat hooked, with a cone^ 

 shaped projecting grinder, and this is surrounded by a spoon-shaped edge, 

 turned toward the hollow of the mouth, so that the cone cannot be seen 

 from the outside ; and the whole grinder, or hard, enamelled part, has 

 the appearance of the back part of the bowl of a spoon — the edge, like a 

 screen, suiTounding the short cone, but so that two deep furrows remain 

 between. Except this grinder, the rest of the body is uniformly round, 

 and the surface almost even. As pre\iously said, however, these by 

 themselves afford no reliable indication as to age. 



Figures 2, 3, 4, 5, 6 show how the age of a colt may be determined 

 till he is two years old. The following further explanations, taken in 

 connection with the chart from Fig. 7 to Fig. 46, inclusive, will teach 

 how the age, from two to thirty, can be ascertained. 



Large horses have, of course, larger teeth than small ones ; but taking 

 a horse of medium size as a standard, one can make allowances for either 

 larger or smaller, and easily arrive at just conclusions. 



The incisors being our main reliance, our remarks must be understood 

 to refer chiefly to them. The length of the tooth of a horse of medium 

 size is three inches, or thirty-six lines. After the changed tooth has 

 arrived at its proper length, it shoots up a line regularly every year, and 

 if the teeth stand right, the grinder is worn off a line every year. It is 

 also, as has been said, worn off in both width and breadth, so that the 

 grinder becomes, from year to year, shorter and smaller, as shown by the 

 chart. 



If, however, the teeth stand too far forward, (in-egular teeth, seo 

 ehart. Fig. 41), they do not wear down in the same proportion as they 

 shoot upward, and they become very long. The age in this case can be 

 ascertained with ease and exactness by observing directions given under 

 Fig. 41, and noticing with care the following points : At the age of five 

 years, the corner teeth of the low^er jaw have grown up five lines above 

 the gum ; each middle tooth, seven lines ; and each nipper, nine. At 

 eight years, and older, each corner tooth of the same horse projects only 



