of the Animals of the Farm. 
435 
Fig. 48. — Incisors and Tuslcs of Pig at one year. 
the mouth, and may be readily known by their sharp unworn 
points, and their recent appearance, as shown in the illustra- 
tion (Fig. 49, p. 436). These teeth are very regular in their 
development, and afford valuable evidence in cases where an 
opinion cannot be formed from an inspection of the incisors 
alone. 
The next change in the dentition is the final one, and occurs 
between the age of seventeen and eighteen months. At this 
period the sixth molar, a permanent tooth, is cut ; and in 
forward animals the lateral temporary incisors are changed for 
permanent teeth. In many instances the temporary lateral teeth 
remain up to the age of eighteen months, although they are in 
such cases quite loose ; and very often the permanent teeth are 
2 F 2 
