of the Animals of the Farm. 



43 



years and ten months old, while in some instances they are not 

 cut until three years and six months, or even later. 



In the illustration opposite (Fig. 38), the state of the incisor 

 teeth in forwai^d animals at two years and ten months is depicted. 



The eruption of the corner permanent incisors, the fourth 

 pair of broad teeth, completes the permanent dentition of the 

 ox ; and from what has been stated in regard to irregular erup- 

 tion of the corner teeth, an examiner will realise how necessary 



Fig. 39. — Incisors of Ox at five years. 



it is to be careful in judging an animal's age on the evidence 

 afforded by them. 



After this period the changes in the form of the teeth which 

 are due to attrition will assist the expert in forming an 

 opinion of the age ; but no exact estimate can be based on such 

 evidence. The five-year-old ox (Fig. 39, above) will show a 

 considerable amount of worn surface in the central, middle, and 

 lateral incisors, and the cutting edge of the corner teeth will 

 be marked by a line of wear ; but no one would attempt 



