PROCO^SS OF TEETHIXa. 37 



At 4 years tlie central nippers will be fully 

 developed, witli the edge somewhat worn off, 

 and the mark in them shorter, wider and feinte-^- 

 the next pair will have made their aj)pearance 

 with the mark deep^ and extending entirely 

 across them. The corner nippers will he larger 

 than the inside ones, yet smaller than they were 

 and flat, with the mark nearly effaced. The 

 sixth grinder will have become level with the 

 others, and the tushes beginning to make their 

 appearance. 



At 5 years the horse's mouth is almost per- 

 fect. The corner nippers are quite up with the 

 long, deep mark, irregular on the inside, and 

 the other nippers bearing evident tokens of in- 

 creasing wearing. The tush is much grown, 

 the grooves have almost or quite disaj)peared, 

 and the outer surface is regularly convex: 



At 6 years the mark on the central nippers is 

 worn out, though there is still a difference in 

 the color of the centre of the teeth. The ce- 

 ment filling the hole, made by the dipping in 

 of enamel, will present a browner hue than the 

 other part of the teeth. 



