THE HORSE 43 



they (the hooks) never come in contact with each 

 other. 



The horse has always attained the age of four 

 and a half or five years before he has a full num- 

 ber of perfect teeth. Before this time, the younger 

 the animal the fewer the teeth, and even these are 

 not all permanent. 



The more a permanent incisor loses in 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 some- 

 what 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, enameled part, 

 has the appearance of the back part of the bowl of 

 a spoon — the edge, like a screen, surrounding 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 previously said, however, these by 

 themselves afford no reliable indication as to age. 



Large horses have, of course, larger teeth than 

 small ones ; but taking a horse of medium size as 



