AGE, AS INDICATED BY THE TEETH. 315 



body of the tooth consists. As age increases, this indication of the fanff 



Fig. 151. 

 Tooth Showing Mark and Fang-Hole. 



hole, which is sometimes called the '*' Secondary mark " becomes rather 



more plain. It, however, affords no reliable data by 



which to judge of the age, and is only mentioned in 



this place, lest the reader should mistake it for the 



remains of the infundibulum. The enamel, it will 



be remembered, is pearly white, whilst the mark of 



the fang-hole is brownish-yellow. The position of 



the fang-hole, marked B, is shown in Figure 151. 



Further Changes indicating the Age. — It will 

 be seen, that about nine the " marks " entirely fail ns, 

 and indeed after seven or eight they can hardly be 

 said to afford any very reliable data. 



From eight years old and upwards the best indica- 

 tions of the age arc given by the gradual alterations 

 which take place in the shape of the teeth from wear 

 and in closing of the mouth. 



Lateral hreadtli, etc. — The teeth originally are 

 hroad laterally at their upper surfaces, otherwise 

 called their croAvns or "tables," and thin from front 

 to rear. Figs, 142, 143, and 144. They narrow grad- 

 ually towards their necks and fangs. Hence, as their 

 upper surfaces wear off, the teeth become narrower 

 year by year. In very old horses there is often a posi- 

 tive interval between the teeth, Figures 160 and 161 Fiq, 153. 



, ,, Ti !• 1 • 11 • Changes in the Crown 



and they appear like sticks m the jaw. of tij^ xeeth. 



