VETERINARY DENTAL SURGE If)'. 33 



external surface and slightly concave on their internal 

 surface, with a groove running the whole length of 

 the tooth. As the teeth become older they change 

 in color, and assume more of a yellowish tint. The 

 growth of the jaw forces 1 them apart, so that each 

 tooth stands by itself. These teeth, unlike the per- 

 manent ones, are seldom covered with a thick coat of 

 tartar. 



The molars are about an inch and a quarter in 

 length and nearly an inch in diameter. The short 

 transverse diameter of the upper molars is about 

 three-quarters of an inch, and of the lower molars 

 much less. The temporary molars are much smaller 

 than the corresponding permanent ones. 



The incisor teeth are shed in the order in which 

 they are cut. The first pair is replaced by permanent 

 teeth at two and a half to three years, and are up and 

 in wear before the next pair are ready for shedding, 

 thus leaving two pairs of sound teeth in wear for 

 masticating food, during the whole process of shed- 

 ding. The second pair are shed at three and one-half 

 to four years, and the third at four and one-half to 

 five years. At five years of age the permanent teeth 

 are all up and in wear. All incisor teeth, both tem- 

 porary and permanent, present their anterior side 

 first; after they are in wear for a short time, it is 

 reduced to a level with the inner surface. 



The fourth molar makes its appearance at the 



