MARKS OF AGE, AND ABUSES. 



471 



age of about eight months. At one year old, the central and 

 the second pairs of nippers are worn nearly level, and the 

 corner tooth, which is now of the same length as its neigh- 

 bors, is rapidly becoming so. 



The two-year old colt has the mark, or kernel — the dark, 

 hard substance in the middle of the crown of the tooth — 

 ground quite out of all the front teeth, or nippers. So far 



LOWER NIPPEBS AND TUSHES OP A FIYE-YEAB OLD HORSE. 



1 1, Central nippers, with their marks almost entirely worn out. 



2 2, Next nippers, showing marks partially worn. 



3 3, Corner nippers, with the marks plainly seen, but the edges giving evi- 



dence of wear. 



4 4, Tushes, with the groove inside aln\ost obliterated. 



the young animal has got along very well with his milk teeth, 

 but now he begins to need others, not merely larger, but also 

 of a firmer, more durable composition and setting ; and this 

 necessity Nature meets by commencing the replacement of 

 the first set by the 'permanent teeth. This operation begins 



