VE TERINAR T DENT A L S URGER T. 1 45 



and one-half to three; three and one-half to four 

 years, and their full growth can be considered at the 

 time when the tables of the teeth are in perfect con- 

 tact. The growth however does not stop at that 

 time. I believe their growth out of the alveoli 

 keeps on going if opposed by the rubbing of a tooth 

 opposite; an even wearing takes place if nothing 

 arrests it; or if there is no wearing the tooth keeps 

 on growing out of its cavity and may overlap or 

 overgrow the other teeth by inches. In other words 

 the free part after having reached its full develop- 

 ment, if not exposed to wear, is growing. The 

 tooth becomes too long, but its length is made at the 

 expense of its root which becomes shorter. Take a 

 tooth which has not been in wear, as in the case of 

 the opposite being removed; let it grow to its 

 utmost, then pull it. Its roots will be very short. 

 Again take one which is softer than normal, it 

 undergoes an excess of wear. When it is project- 

 ing but little, extract it and the roots will be corre- 

 spondingly longer. And then again take that of a 

 very old horse in which the wearing has been per- 

 fect and then both roots will be very small." 



It is of great importance in operating that we 

 should know when the tooth ceases to grow, for 

 operations may be performed on a full grown tooth 

 that would not be admissible where the pulp exists to 

 any considerable extent. The pulp is highly supplied 



