84 

 penetrates through the gum, and before it is fully up 

 the covering of the third permanent molar is re- 

 moved. This effected, the colt has six molars on 

 either side of both jaws, and whenever that number 

 is found they may be assumed to be all of a per- 

 manent character ; so at four years old the tables of 

 the central incisors exhibit some considerable wear, 

 the infundibula no longer extend entirely across, but 

 have become circumscribed and well defined. The 

 tables of the lateral incisors, on the contrary, are 

 only beginning to be formed, and very often the part 

 posterior to the infundibulum has not received any 

 attrition. The infundibula in these last extend the 

 entire breadth of the table, and in consequence of 

 an indentation on that side which touches the corner 

 milk teeth, the space is there free. The reader will 

 comprehend this particular formation, by referring to 

 the wood-cut of the table of the tooth presented at 

 page 79, the appearance being so much alike as not 

 to necessitate a repetition to enforce it. When the 

 fourth year, however, has been for a month or two 

 perfected, the tables then assume the form represented 

 in the following wood-cut, which exhibits the change 

 that has taken place in the central incisor, and also 



