8 Dentition as indicative of the Age 



of the structures of the tooth in the shape of a hollow cone, 

 the apex of which reaches into the fang. In the recent tooth 

 the cavity extends quite across the table, but, necessarily, as 

 the tooth is worn it becomes more and more circumscribed, 

 and at length the apex of the hollow cone is reached, and 

 the "mark" consists of a mere speck, and then is entirely 

 obliterated. 



Owing to the inflexion of the whole of the tooth-structures 

 to form the hollow cone, the tables of the incisors have, besides 

 the ivory and crusta, two distinct rings of enamel, which are 

 distinguished from the other parts by their pearly whiteness — 

 an external or larger ring which forms the outline of the table, 

 and a central ring which surrounds the cavity in the centre of 

 the table. That part of the tooth which is situated in the front 

 of the mark is described as the anterior edge, and the portion 

 behind it as the posterior edge. 



All these parts are indicated in the diagram (Fig. 2), and it 

 is necessary that the reader should clearly recognise them, in 

 order to understand the description of the changes which are 

 occasioned by the wear to which the teeth are subjected. 



While the temporary dentition is proceeding, and also during 

 the time that the permanent are taking the places of the tem- 

 porary teeth, the examiner may form an opinion of the age by 

 merely noting what teeth are in the mouth; but when these 

 changes are completed, he is compelled to base his conclusion 

 upon the evidence which he gains from an inspection of the 

 tables of the incisor teeth, those of the lower jaw being gene- 

 rally selected. In doing this, he has to observe whether the 

 cavity or mark extends across the tooth, or is surrounded by a 

 line of worn structure, in which case the table is said to be fully 

 formed, as it appears in Fig. 2. The width of the worn surface 

 in front of the cavity, as compared with that at the back, should' 

 be taken into consideration, and also the shape of the table, 

 whether oval, or square, or triangular. 



No particular importance can be attached to the tusks as a 

 means of judging the age. They only occur in the horse, and> 

 are less regular than the other teeth in the time of their erup- 

 tion. The small rudimentary teeth which sometimes exist in 

 place of tusks in the mare need not be taken into account at 

 all. 



There may in certain cases be reason to suspect that the 

 mouth of the horse under examination has been manipulated, 

 with the view to make the animal appear younger or older than 

 it really is. Up to the age of five years it may be advantageous 

 to the seller to convince the purchaser that the horse is above 



