HORSES AND MULES 



47 



FIG. 2. At two years of 

 age the jaw shows greater width 

 than at one year of age, and the 

 teeth are all in contact and show 

 considerable wear. 



FIG. 1. At^one year of age the 

 jaw is narrow, the temporary teeth 

 are small and the corner incisors are 

 not yet in contact. 



FIG. 3. At three years of 

 age the permanent incisors above 

 and 'below are in wear. Note the 

 greater width and length in com- 

 parison to the temporary teeth. 



FIG. 4. At four years 

 of age the permanent and in- 

 termediate incisors on lower 

 and upper jaws are in wear. 

 The corner pair of temporary 

 teeth have not been dis- 

 placed; they appear very 

 small in comparison with the 

 permanent teeth. 



NOTE. Photographs showing teeth at various ages, by courtesy of Prof. S. T. 

 &fmpson, Agricultural Extension Service, Missouri Experiment Station. 



