LOWER INCISORS. 



5. A horse's lower incisors are shown at seven years. The hinder part of the table in 

 the corner incisors is well in wear. The tushes are now growing much longer in appearance. 



6. A horse's incisors at eight years. The central incisors are losing their mark, and the 

 table of the tooth is now fairly triangular in its outline ; the inner enamel ring in the lateral 

 incisors is less elongated. When a horse has turned eight it is usual to speak of such as 

 being "aged." After this age it is impossible to form any accurate or fairly accurate 

 opinion as to its age. 



7. A horse's lower incisors about twelve years. All these teeth are assuming the 

 triangular. 



8. The teeth of a very old horse. The great length of the teeth is due to shrinkage of 

 the gum. The dental arch has now become almost obliterated ; the age is probably about 

 thirty years. 



D. Sucking or milk tooth. 



E. Permanent tooth. 



F. Permanent tooth ; unworn sucking tooth. 



[Facing page 54. 



