THE STRUCTURE OF THE TEETH 67 



be left where the second stood, or they will begin to peep 

 above the gum, and the corner ones will be diminished in 

 breadth, worn down, and the mark becoming small and 

 faint. At this period, likewise, the second pair of grinders 

 will be shed, and, previous to this, will be the attempt of 

 the dealer to give to his three-year-old an additional year, 

 but the fraud may be detected by an examination similar 

 to that which we have already described. 



Four Years Old. — Here the two lateral horse- teeth are 

 seen with the full " bean " in them, the two front incisors 

 doing the principal work, as is shown by their surfaces 

 and their inner enamel edge. We have here four pairs of 

 horse-teeth well up (in the two jaws), the two outside milk- 

 teeth in each remaining. In the outside view the gum 

 is swelling, and the corner milk nippers are about to go. 

 The horise incisors will soon come in their place. The 

 surface of the teeth is clearly delineated in our dental 

 map. Yon here perceive the central nippers fully de- 

 veloped, the edge somewhat worn off, the mark shorter, 

 and wider, and fainter. The next pair will be up, but 

 they will be small, with the mark deep, and extending 

 quite across them, the corner nippers larger than the 

 inside ones, yet smaller than they were, fiat, and the mark 

 nearly effaced. In the back part the sixth grinder will 

 have risen to a level with the others, and the tushes will 

 begin to appear. 



Now, more than at any other time, will the dealer be 

 anxious to put an additional year upon the animal ; for 

 the difference between a four-year-old colt and a five-year- 

 old horse in strength, utility, and value is very great ; 

 but the want of wear in the other nippers, the small size 

 of the corner ones, the little or no growth of the tush, 

 the smallness of the second grinder, the low forehand, 

 the legginess of the colt, and the thickness and little 

 depth of the mouth, will, with the man of experience, 

 detect the cheat. 



The tushes are four in number, two in each jaw, situated 

 between the nippers and the grinders, much nearer to the 

 former than the latter, and nearer in the lower jaw than 

 in the upper ; but this distance increases in both jaws 

 with the age of the animal. In shape, they somewhat 

 resemble a cone, protruding about an inch from the gum, 

 and having their extremity sharp-pointed and curved. 



