TOOTH INDICATIONS OF AGE AFTER EIGHT 499 



and a hollow or saddle-back. From Galvayne's Twentieth 

 Century Book on the Horse, with acknowledgments. 



To make an animal look young, the teeth of old horses 

 are sometimes " bishoped " by low dealers that is, artificial 

 hollows are made in their crowns,, but the deception is easily 

 recognised by the absence of the marginal ring of enamel. 



It is claimed for the method described by Galvayne, of 

 studying the changes that take place as the teeth wear, that 

 the age of a horse between ten and thirty can be accurately 

 determined within a margin of one year. He says : " When 

 the lower permanent incisors are first developed they are 



When first 

 developed at 

 five years. 



At fifteen 

 to sixteen 

 years. 



At thirty 

 years. 



FIG. 37. Side view of both 

 jaws at nearly twenty years 

 of age. 



Fio. 38. Sections of an incisor 



Reduced from Galvayne's Twentieth Century Book on the Horse* 



quite twice as wide across as they are thick through. In 

 a thirty-year-old horse they are just the opposite, namely, 

 twice as thick through as they are wide across. At 

 twenty the thickness through of the two centrals is 

 approximately equal to the width. In the young horse the 

 teeth are nearly perpendicular. In the old one they are 

 at an angle of 30 to 40, according to age. When first fully 

 developed the lower centrals are usually nearly three inches 

 long," but wear with age, as indicated in Fig. 37. " In 

 an old horse the gums become atrophied. In a young 

 animal the gums are full and circular in formation round 

 the teeth." 



A valuable auxiliary to the foregoing indications of age 



