THE TEETH. 171 



central front teeth appear either before or soon after birth, and in 

 about three weeks after birth, the whole of the twenty temporary 

 teeth appear. The first change in the teeth occurs at the age of 

 three months, when the lamb cuts a permanent molar tooth. The 

 next change also occurs at the back of the mouth, when at nine 

 months old, another, the second permanent molar tooth appears. 

 At one year old the lamb has but eight permanent teeth, or two at 

 the back of each side of each jaw. The age of fourteen months is 

 marked by the appearance of two permanent incisor teeth at the 

 center of the front of the jaw. In judging of the age of a sheep, 

 the condition of the molars may be studied with advantage. If a 

 sheep is certified to be not exceeding one year old, and the fifth 

 molar, (the second permanent one, and the last one on each jaw), is 

 found to be sharp on the edges and but slightly worn, the age may 

 be regarded to be properly stated, even though the central pair of 

 front teeth have already appeared. But if these teeth are well up 

 and the last molar is worn and smooth, and there is a space be- 

 tween this tooth and the angle of the jaw, the sheep is certainly 

 over a year old. The sixth molar tooth is in its place at the age 

 of eighteen months, and this is the only test of this age of the 

 sheep. The second pair of front teeth, one on each side of the 

 first pair, appear at twenty-one months of age, and at two years 

 are fully grown and stand well up from the gum and level with 

 the first pair. After the sixth molar is cut, the three forward and 

 temporary molars are replaced by permanent teeth, which are 

 fully grown at the age of twenty-seven months. At two years 

 and a half the third pair of front teeth have become fully grown, 

 although in some forward sheep of the quickly maturing breeds, 

 these teeth may appear at two years of age. Generally they indi- 

 cate an age of two years and a half. At the age of three j^ears, in 

 the Cots wolds and other forward breeds, the fourth and last pair 

 of front teeth appear; but in other breeds they are not present 

 until three and a quarter or three and a half years. The sheep is 

 then what is known as " full mouthed." The following table of 

 the periods of dentition will be found useful in determining the 

 age of a sheep : 



At one month, 8 temporary front teeth and three temporary molars on 

 each side of each jaw. 



At three months, a permanent molar is added to these three. 

 At nine months, the second permanent molar appears. 

 At fourteen months, two permanent incisors appear, (as a, a, fig. 62). 

 At eighteen months, the third permanent molar appears. 

 At twenty-one months, there are four permanent incisors, ( a,ot,fig. 63) 



