532 



3160. A premolar of the upper jaw, with the last remnant of the crown of the deci- 

 duous molar which it was about to displace, of a Horse. 



The absorbed surface of the crown is so exactly coadapted to the inequalities of that of the 

 succeeding tooth, as to be firmly attached to it, although a part of the new crown has come 

 into use : here therefore we have an instance of a grinding surface being formed by two teeth 

 projecting from the same socket. 



Hunterian. 



3161. A transverse section of the lower jaw of the Horse, exposing a molar tooth in 

 its alveolar cavity, and showing the great extent of the crown therein im- 

 bedded. Purchased. 



3162. Portions of two longitudinally bisected incisors of a Horse. 



They show the long conical pulp-cavity extending into the crown from the base, and the 

 cavity produced by the inflected fold of the matrix extending in the opposite direction, or 

 from the crown towards the base. A layer of enamel and cement are continued into this 

 cavity, as upon the exterior of the tooth. 



Presented by Sir Everard Home, Bart., V.P.B.S. 



3163. The left lower canine of a Horse. 



The short enamelled crown is convex on the outside : it has two longitudinal impressions 

 on the inside, near the margins of the crown, producing a wavy transverse section on that 

 side. 



Hunterian. 



3164. The second premolar, left side, upper jaw, of a Horse. 



The crown, which has been cut transversely and polished, shows the sinuous folds of enamel 

 surrounding the dentine and inflected into the interior of the crown, with the dentine on one 

 side of the enamel and the thick cement on the other side. The degree of polish corresponds 

 with the degree of density of these different substances. 



Hunterian. 



3165. The first true molar, right side, upper jaw, similarly prepared, of a Horse. 



Hunterian. 



3166. The first true molar, left side, upper jaw, of a Horse. 



It has been longitudinally bisected, to show the depth of the internal folds of the enamel 

 and cement. A transverse section has been removed from the outer moiety of this tooth. 



Hunterian. 



