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Farmers* Bulletin 1066. 



At 3J years the second intermediates or laterals are cut. They are 

 on a level with the first intermediates and begin to wear at 4 years. 



Fig. 4. — Internal face of incisors at 4 years. 



At to 5 years the corner teeth are replaced, the animal at 5 

 years having the full complement of incisors with the corners fully 

 developed. 



Fig. 5. — Internal face of incisors at 5 years. 



At 5 to 6 years there is a leveling of the permanent pinchers, the 

 pinchers usually being leveled at six and both pairs of intermediates 

 partially leveled and the corner incisors showing wear. 



From seven to eight the pinchers are noticeably worn ; from eight 

 to nine the middle pairs, and by ten years the corner teeth. 



After 6 years the arch gradually loses its rounded contour and 

 becomes nearly straight by the twelfth year. In the meantime the 

 teeth have gradually become triangular in shape, distinctly separated, 

 and show the progressive wearing to stubs. 



Fig. 6. — Internal face of incisors at 12 years. 



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