THE TEETH OF MAN. 11 



not in so great degree as is the case in the . anthropoid 

 apes. 



The pulp cavity bears a general resemblance to the ex- 

 ternal contour of the tooth ; towards the cutting edge it is 

 very thin, and is prolonged at its two corners to a slight 

 extent into "cornua;" at the neck it is cylindrical, and is 

 also cylindrical in the root, tapering gradually till it ap- 

 proaches close to the apex, when it becomes suddenly con- 

 stricted. 



Upper lateral incisors are in every dimension some- 

 what smaller than the centrals. They widen somewhat 

 abruptly near to the cutting edge, but below this they taper 

 pretty regularly to the end of the root ; the labial surface 



FIQ. 2 1 . 



is convex in each direction, while the lingual surface is 

 perhaps rather flatter than that of a central incisor. 



The outer (distal) angle of the crown is far more rounded 

 or sloped away than in the centrals, and the distal surface, 

 looking towards the canine, is in a slight degree convex; 

 the median surface may be slightly concave. 



The enamel terminates towards the gum in contours pre- 

 cisely similar to those which obtain in the centrals : but 

 the basal ridge, or cingulum, is often more strongly pro- 

 nounced, and the presence of a central tubercle upon it is 

 less infrequent. From this greater prominence of the cin- 



( J ) Front and side view of a left upper lateral incisor. 



