THE AGE OF SHEEP 563 



similar breadtn, almost flat, and very smooth on their 

 outer surface, and considerably concave internally. 



Fig. 3 shows their aspect at two years of age, in 

 which the two central teeth are considerably broader 

 than the others, with the cutting edge not nearly so 

 much arcuated as at two years. 



Fig. 4 represents the structure of the teeth at 

 three years, from which it will be observed that the 

 four central ones are considerably broader and longer 

 than the other two on each side, which rather suddenly 

 shorten, the external teeth being shortest and narrow- 

 est : the cutting edge of the four central ones is but 

 slightly curved. 



Fig. 5 characterises the teeth at four years, and 

 shows that the six central ones are nearly of uniform 

 breadth and length ; their cutting edge being but 

 very slightly curved, the external tooth on each side 

 being materially shorter than the others. The whole 

 of the teeth are much stronger than in any of the 

 preceding years. 



Fig. 6 shows the structure of the teeth on the fifth 

 year. It will be observed that the whole eight teeth 

 are nearly straight on their cutting margin, and that 

 there is but a small difference in their breadth, and 

 they almost gradually diminish from the centre to 

 the sides. The basal range above the gums is also 

 nearly parallel. 



Fig. 7 shows the character of the teeth on the 

 sixth year, when the general length and breadth con- 

 tinue nearly as in the fourth and fifth years ; but the 

 two central ones are generally considerably worn down, 

 or broken, as exhibited in our figure, and frequently 

 dark-green, or brown, at their base above the gums, 

 and their hue rather yellow. 



As in cattle, so in sheep, selection and feeding 



