ERUPTION OF PERMANENT TEETH. 



179 



Fig. 168. 



I, one year. II, eighteen months. Ill, two years, three months, a, external 



face. 6, mternal face. 



precocious races the eruption of the pinchers takes place at one 

 year, while in the common races it may not until fifteen months. 

 Again, a question of individual development may hasten or 

 retard the eruption by a month or two ; so that the better-bred 



