.")"J .1 1/ /•;/.'/ r.lA Ml ShlM criDK JJ-AiL/iTS 



(lis:ij)j)('ar('(| and the only cnaincl jcniaininji is a vviy narrow strip on the 

 anterior hoidci-. The \V('aiin«i- suifacc lias hcconic elliptical, and the 

 ''(lentul star" has changed IVoni a t lansvei-se hne to a lounded spot. 

 The deposit of cement has incicased to ahnost an eighth of an inch in 

 thickness, re('nfoicin<i- tlie old declininji; root, as it were, to j)rolonjr its 

 ser\ice to the \'ei\' last . 



The base of the ciown lias i)asse(l beyond the <iuni line, and at best 

 the tooth could not last many 3'ears longer. 



It is by the examination of these indications that horsemen ascer- 

 tain the a<>;e, althoup;h it is impossible to judjje accurately in the more 

 a(lvanc(Hl staj2;es. Kspecial att(Mition is j!;iven to the size and shape, 

 pi'esence or absence of the cul-de-sac. known amon^" hoi'semen as the 

 "mark." It should be exj)laine(l howe\'ei-, that the lower incisors which 

 ar(^ more easily examined in the living- horse, bein^- somewhat .smaller 

 and havint;- a shallower cul-de-sac than the uj^pers just described, will 

 acciuire a certain ai)j)eaiance of wear at an earlier age. For instance, if C 

 and 1) wei(^ lowei' teeth they would have a similar aj^pearance at the ages 

 of {>itilit and twelve years. ConsidcMinfi; the incisor set as a whole, it 

 shows other marked changes with the advance of age. To render effec- 

 tive service the teeth nuist be in close contact ; therefore, as each tooth is 

 reduced in diameter it moves sHghtly toward the median line, reducing 

 the total transverse measurement of the set. The meeting angle of 

 upper and lower teeth becomes much more acute in old age. An exhibit 

 labeled ''Series of Horse Muzzles" in the wall case shows the general 

 appearance of the incisor teeth at various ages. 



The canine tooth, which is rareh' found in the female except in a 

 very abortive fomi, is of comparatively simple structure and has no 

 apparent function at the present time, but ma^- have been of sen^ice as a 

 weapon at a ver}^ earh' stage of evolution. It receives almost no wear, 

 has little or none of the compensating movement of the incisors and is, 

 in fact, of no very great interest. 



DESIGNATION OF THE TEETH 



THE deciduous oi- milk teeth, which are shed and replaced by 

 permanent ones, are divided into three classes: in front, the 

 deciduous incisoi's. back of these, the very small deciduous ca- 

 nines, and still farther back, the deciduous molars. 



In th(^ permanent set the incisors and canines have leplaced the de- 

 ciduous ()n(>s, and the (kM'iduous molais liavc^ been replaced by the j^i'e- 

 molai's. Still back of the premolars comes a fourth class, the ixM'manent 

 OI- tiiie molars, which have no deciduous predecessors. 



