84 THE MULE. 



age of three and a half or four j-ears the next pair of 

 nippers will be changed, and the mouth at that time 

 cannot be mistaken. The central nippers will have 

 nearly attained their full growtli, and a vacuity will bo 

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

 above the gum, and the corner ones will be diminished 

 in breadth and worn down, the mark becoming small 

 and faint. At this period also the second pair of grind- 

 ers will be shed. At four years the central nippers will 

 be fully developed, the sharp edges somewhat worn off, 

 and the marks shorter, wider, and fainter. The next 

 pair will be up, but they will be small, with the mark 

 deep and extending quite across. Their corner nippers 

 will be larger than the inside ones, yet smaller than 

 they were, and flat, and nearly worn out. The sixth 

 grinder will have risen to a level with the others ; and 

 the tushes will begin to appear in the male animal. 

 The female seldom has them, althougii the germ is 

 always present in the jaw. At four years and a half, 

 or between that and five, the last important change 

 takes place in the mouth of the mule. The corner nip- 

 pers are shed, and the permanent ones begin to appear. 

 When the central nippers are considerably worn, and 

 the next pair are showing marks of wear, the tush will 

 have protruded, and will generally be a full half inch in 

 height. Externally it has a rounded prominence, with 

 a groove on either side, and is evidently hollow within. 

 At six years old the mark on the central nippers is 

 worn out. There will, however, still be a difference of 

 color in tlie center of the tooth. The cement filling up 

 the hole made by the dipping in of the enamel, will 



