of the Animals of the Farm. 
399 
Fig. 7. — Incisors of Colt at one year. 
mistakes have occurred ; and it is therefore not out of place to 
suggest that care should be taken to discriminate between the 
temporary incisors, and, if necessary, to refer to the molar teeth, 
in order to avoid such embarrassing blunders. 
Under ordinary circumstances it will be more frequently 
necessary to distinguish between a yearling and a two-year-old, 
than between one-year old and five, and it fortunately happens 
that at the age of two years another molar, the fifth in situation^ 
is in the mouth, and may be at once distinguished by its recent 
appearance. Soon after eighteen months the fifth molar begins 
to protrude through the gum, and by the termination of the 
second year is level with the other molars, as shown in Fig. 8, 
p. 400, so that any doubt which may remain after an inspection 
of the incisors may be settled by reference to the condition of 
the molars. 
It will be observed in the figure just referred to that the surfaces 
of four molars are worn level, while the points of the new tooth, 
the fifth in position, are rounded, excepting a small portion at 
the inner side of the tooth, which shows the effects of attrition, 
but only to a slight extent. 
The incisor teeth at two years of age have their tables 
perfectly formed as a rule ; but, in some instances, the corner 
teeth, although they have lost their shell-like character, still 
