ELEMENTS OF HIPPOLOGY. 



33 



At six the hollow of the mark has been worn off the tables 

 of the center teeth, but the enamel is still there; it is discolored, 

 and sometimes appears not very different from the marks in the 

 other teeth — a little less dark and its margin less pronounced. 

 The mark is plainly present in the intermediates and corners, 

 and the wall of the corner tooth is up all around. The tables of 

 the teeth at six usually lose something of the rectangular shape, 

 becoming more rounded on the longer sides. 



Looking at the exterior faces of the teeth, the hook is be- 

 ginning to appear and the teeth are losing their fresh, clean ap- 

 pearance. There is nothing positive to go by in the six-year-old 

 mouth, except the presence of the mark in the intermediates 

 and corner teeth, and even this is sometimes misleading:. 



Figure 22. — The Tables at Five. 



