3138 THE HORSE. 
overtake their fellows. Between the sixth and ninth months the corner 
nippers are cut, and towards the end of the first year reach their full size. 
This first set of nippers consists of teeth considerably smaller in size than 
the permanent teeth and somewhat different in shape. They are more 
rounded in front, and hollow towards the mouth, the outer edge being at 
first much higher than the inner. As they wear down, these two edges 
soon become level, but the corner nippers maintain this appearance for 
a long time. At six months the central nippers are almost level, with 
the black “mark” in their middle wide and faint ; and about the ninth 
month the next nipper on each side above and below is also worn down 
almost to a level surface. 
DvuRING THE SECOND YEAR the following changes take place :—In the 
first month, and sometimes towards the end of the first year, a fourth 
grinder is cut all round, which commences the set of permanent teeth, 
the three first molars only being shed. At a year and a half, the mark 
in the central nippers is much worn out, and has become very faint ; the 
second is also worn flat, but is not so faint; and the corner nippers are 
Hic. 6.—THREE-YEAR-OLD Mouvu. 
&. Anterior maxillary bone. 3. 3. Corner milk teeth, still showing central 
1. 1. Central permanent nippers, nearly full- mark. 
grown. 4, 4. Tushes concealed within the jaw. 
2, 2. Milk teeth worn down. 
flat, but present the mark clearly enough. In colts which have been 
reared on corn and much hay, the wearing down proceeds more rapidly 
than in those fed upon grass alone. 
THE THIRD YEAR is occupied by the commencement of the second 
dentition, which is effected in the same order in which the milk teeth 
