Horse’s Teeth 55 
a colt becomes a horse and a filly becomes a mare. 
The temporary teeth are usually shed easily; the per- 
manent teeth pushing up from below cause the roots of 
the temporary ones to be absorbed, until they finally 
become mere “ caps,” 
attached to the gum. 
Sometimes the tem- 
porary corner in- 
cisors are extracted 
in order to make a 
colt or a filly appear 
older than it is. 
Such a practice is not 
to be commended. 
When the perma- 
nent incisors are first 
erupted, well-defined 
“date-cavities” exist 
in their upper sur- 
faces. These cavi- 
ties, dark brown or 
black in color, nar- 
-vow from before back 
and wide from side to 
side, extend quite a 
depth into the tooth. Hach date-cavity is surrounded 
by a very narrow band of enamel, which can be 
distinguished from the yellower dentine that com- 
poses most of the substance of the tooth. The date- 
cavities wear out and disappear from the lower incisors 
at the following ages: From the lower central incisors 
Fig. 19. Horse’s teeth at six years of age 
Fig. 20. Horse’s teeth at seven years of age 
