THIRD PERIOD. 



ERUPTION" OF THE PERMANENT OR ADULT TEETH. 



This period commences at the age of two or two and a 

 half years, and finishes at five years. 



About Two and a Half Years. — Successive falling out of 

 the temporary pincher teeth; swelling of the gums and appear- 

 ance of the anterior borders of the permanent pinchers. Ordi- 

 narily these teeth appear in the superior jaw first, and the 

 piercing of the gums is completely effected in about six weeks 

 to two months. 



Rising Three Years. — As the colt is approaching the age 

 of three years, we find in the superior jaw the permanent 

 pinchers wholly out of the gums and almost reaching the level 

 of the temporary intermediate teeth. In the inferior jaw, the 

 borders and sometimes a greater extent of the free extremities of 

 the teeth have appeared through the gums, though the teeth are 

 still virgin ; the intermediate temporary teeth are free from the 

 gums at their neck, and very much worn. The corner teeth 

 are worn so that they touch each other by their external 

 borders. (Figs. ^^, m, 67.) 



Three Years. — At three years of age all of the permanent 

 pinchers are out of the gums and have reached the level of the 

 temporary teeth. The permanent pinchers are wider trans- 

 versely, square, and darker in color than the temporary teeth, 

 and show little gutters on their anterior face. They differ dis- 

 tinctly from the others, which are smaller, more convex, have a 

 constriction in the neighborhood of the gums, are whiter, and 

 are not marked with gutters. 

 (74) 



