472 ORGANS OF DIGESTION. 



very concave: owing to their thinness for some distance from 

 the cutting edge, they are apt to be broken. In early life, their 

 cutting edge is slightly serrated. They have each but one 

 root, which is conoidal, terminates by a sharp point, and is not 

 unfrequently impressed longitudinally on each side by a super- 

 ficial furrow. 



The central incisors of the upper jaw are broader and longer 

 than the outer ones ; the anterior face of the latter is more con- 

 vex, and their cutting edge more rounded. The incisors of the 

 lower jaw are much narrower than those of the upper, and 

 have their roots flattened on the sides; they do not differ essen- 

 tially among themselves, except that the external ones are some- 

 what wider than the internal. 



The enamel of the incisors is continued farther down, and is 

 thicker on their anterior and posterior surfaces than laterally; 

 it is also thicker on the front than on the back part.* 



The Cuspated Teeth (Denies Cuspidati, Canini,) are next to 

 the incisors, one on each side. Their body is conoidal, and is 

 brought to a sharp point at its summit; the principal obliquity 

 in effecting the latter, being on the side of the interior of the 

 mouth. They are more convex externally, than the incisors, 

 but not so concave internally, they are also thicker and more 

 cylindroid. They have each but one root, which is conoidal, 

 and which, as also the body, is longer than the corresponding 

 portion of any of the other teeth. They stand nearly perpen- 

 dicularly, and are more covered on their sides with enamel 

 than the incisors. 



The cuspated teeth of the upper jaw have longer roots than 

 those of the lower, and are called, in common language, eye- 

 teeth : those of the lower jaw sometimes are called stomach- 

 teeth. 



The Bicuspated Teeth (Denies Bicuspidati,) two in number 

 on each side, are situated behind the cuspate; they are also 

 called small molar. They are almost precisely alike, with the 

 exception that the first is smaller than the other, and resembles 

 rather more the type of the cuspidatus than the second does. 



* Natural History of the Human Teeth, by J. Hunter, London, 1778. 



