ANIMAL DENTISTR"y. 



61 



months, assumes the shape of a tooth during the second year, 

 reaches the alveolar border at three years, expels the tem- 

 porary shell at three and a half years and takes its place at 

 the level of the arcade at four years. 



Comer Incisor — Is very rudimentary at one year, begins 

 to develop at two years, assumes the shape of a tooth at 

 three years, reaches the alveolar border at four years, expels 

 the temporary shell at four and a half years and takes its 



Fig. 44. 

 Molars of a Horse Approaching the Age of 2 Years. 



place at the level of the arcade at five to five and a half years. 



Canines — Erupt at the age of four to four and a half 

 years, but may be delayed in their outward course by the 

 hardness of the jaw. Occasionally their growth, especially 

 of the superiors, is arrested beneath the gums until the sev- 

 enth year of the animal's life. The inferior canines always 

 erupt slightly in advance of the superior. 



First, second and third molars begin to develop in the 

 foetal life of thie colt. At birth they are small, rudimentary 



