THE AGE. 119 



At SIX years, tlie mark is almost gone from the second 

 [)air, and the outer edge of the corner teeth is 'worn down. 



At seven years, the mark is entirely gone from the second 

 pair, the edges of the corner teeth are worn somewhat flat; 

 though there is still a slight cavity in the centre. 



At eight years, the teeth of the lower jaw are worn en- 

 tirely flat, the mark having disappeared from all of them. 

 The form of the surface of the tooth has become oval, and 

 the central enamel is long from side to side, and is near to 

 the front of the tooth. 



At nine years, the middle nippers are rounded on the 

 inner side, the oval of the second pair and of the corner 

 teeth becomes broader, the central enamel is nearer to the 

 inner side, and the marks have disappeared from the teeth 

 of the upper jaw (fig. 5). 



At ten years, the second pair are rounded on the inner 

 side, and the central enamel is very near to the inner side. 



At eleven years, the corner teeth are rounded, and the 

 central enamel becomes very narrow. 



At twelve years, the nippers are all rounded, and the cen- 

 tral enamel has entirely disappeared from the lower jaw, 

 but it may still be seen in the upper jaw. 



At thirteen years, the middle nippers commence to assume 

 a triangular form in the lower jaw, and the central enamel 

 has entirely disappeared from the corner teeth -of the up- 

 per jaw. 



At fourteen years, the middle nippers have become trian 

 gular, and the second'pair are assuming that form. The 

 central enamel has diminished in the middle nippers of the 

 upper jaw. 



At fifteen years, the second pair have become triangular; 

 the central emamel is still visible in the upper jaw. 



At sixteen years, all of the teeth in the lower jaw have 



