_The Corner Teeth only show slight wear, and the posterior Margins are round._] [Illustration: _SIX YEARS OFF._ _The Corner Teeth look more firmly set, and their edges begin to be uneven._] 49. _At six years of age, the corner teeth look more firmly set, and their edges begin to be uneven_; they have become more square in the figure of the external surface; the edges of the teeth, when the mouth is closed, fairly meet; the round appearance of the posterior border is nearly lost, and the teeth are altogether of a most prominent character. The table of the corner teeth, nevertheless, is still confined to the part anterior to the infundibulum, which cavity is not yet fairly circumscribed or surrounded by a level margin. The infundibula may be lost in the central incisors, and those of the lateral teeth may begin to look shallow; but more generally these cavities are retained at six years old. The tables, likewise, have somewhat changed their positions, and the semi-circle which they formed at the fifth year, now is hardly so perfect, though still well marked. The above description will be the better understood by reference to the coloured engraving, which has been compared with the mouths of numerous animals, viz., Skeleton Sorella, and a brown horse, the property of Mr. T. Brown, &c., &c. The reader, however, will at once recognise the general truth of the drawing, the purpose of which the accompanying wood-cut will serve to explain. The alteration in the semi-circular arrangement will be better perceived by contrasting the present diagram with the one which preceded it, and though the change may not seem very great, nevertheless, sufficient is indicated to instruct the eye accustomed to observe it. The corner teeth have now acquired a degree of surface which will fairly represent a table, though it is still imperfect. The more darkly shaded portion of the separated table denotes the part which has yet received no attrition, but notwithstanding it is readily discerned that the nipper has come into active use. [Illustration]