322 THE HORSE, 
the nippers gradually extend themselves in a straight line from each jaw, 
and, in the very old horse, form an acute angle between them. 
AT ABOUT THE EIGHTH YEAR, the upper nippers present the samo 
appearance as already described in the lower nippers at six years old. 
Both tushes are considerably worn away at their points, and the upper 
ones more so than the lower. 
AT NINE YEARS OF AGE the upper middle nippers are worn down com- 
pletely. The next pair have a slight mark left, but their surfaces are 
quite level, and the corner nippers have only a black stain, without any 
central depression. 
. 
Fia. 10.—THr Lower NIPPERS AND ldSHES oF A S1x-YEAR-OLD HorsE, 
B. The lower jaw. plainly enough, but with the edges of 
i. 1. The central nippers, with the marks the cavity considerably worn. 
worn out. 4. 4, The tushes, standing up three-quarters of 
2, 2. The next nippers, with the marks dis- an inch, with their points only slightly 
appearing. blunted. 
8, 3. The corner nippers, showing the mark 
AFTER NINE YEARS the age of the horse can only be guessed at from his 
teeth, which gradually grow in length, and are more in a line with the 
jaw. The section of each nipper presented to the eye becomes more and 
more triangular instead of being oval, as seen in figs. 10 and 11; but after 
about the twelfth year the triangular section disappears, and the tooth 
becomes nearly round. In accordance with the increase of length is the 
colour of the tooth altered, being of a dirty yellow in very old horses, with 
occasional streaks of brown and black. The tushes wear down to a very 
small size, and very often one or both drop out. 
ALLUSION HAS ALREADY BEEN MADE to the practice of removing the 
milk nippers for the purpose of inducing a more rapid growth of the next 
set, which, however, is not materially affected by the operation , but dis- 
