ANIMAL DENTISTRY. 59 



entire jaw behind the interdental space until the age of ten 

 months. In the herbivora the fourth molar forces its way 

 to the surface in the same relative position that the sixth 

 molar occupies in the mature animal. The jaw is therefore 

 always filled with molars, the fourth, fifth and sixth forcing 

 their way behind their successive neighbors. 



Fig. 42. 

 Molars of a Horse Approaching 5 to 6 Months. 



During the first year the only prominent visible event in 

 the evolution of the permanent teeth is the eruption of the 

 fourth molar. The invisible events occurring in the germs 

 located at the roots of the temporary are, however, of no 

 less importance. They are developing rapidly into teeth of 

 normal shape and size, gradually transgressing upon and 

 shortening by absorption the fangs of the temporary teeth, 



