APPENDIX xiii 



THE Cow 



The cow has eight incisors in the lower jaw and none above. The middle 

 pair, as in the horse, are known as the middles ; the next, as the first inter- 

 mediates ; the third pair, as the second intermediates ; and the outer pair, as 

 the corners, or laterals. 



At birth the calf usually possesses the middles ; if not, they make their ap- 

 pearance in a very few days and are followed within the first month by the 

 remaining incisors. When the animal is from eighteen to twenty-four months 

 old the middle pair of milk teeth is erupted and the permanent ones take their 

 place. A similar change occurs in the first intermediates at from twenty-seven 

 to thirty-six months, in the second intermediates at from thirty-six to forty- 

 eight months, and in the corners at from forty-five to sixty months. After this 

 the age can be only roughly estimated from the wear shown by the teeth. 



THE SHEEP 



The sheep, like the cow, has eight incisors in the lower jaw and none above. 



Incisors are usually not present in the mouth of the lamb at birth, but by the 

 end of the first month are all in. The milk teeth are replaced by the perma- 

 nent teeth as follows : the middles, at from fifteen to eighteen months ; the first 

 intermediates, at about two years; the second intermediates, at from three to 

 three and one-half years ; and the corners, at from four to four and one-half 

 years. After this the determination of age is largely a matter of guesswork, 

 for the wear of the teeth varies greatly, and depends upon both the animal 

 and the feed. 



THE PIG 



The pig has six incisors in either jaw, the corner pairs being present at birth 

 and the middles and intermediates appearing when the animal is three or four 

 months old. At from six to ten months the corners are replaced by the per- 

 manent corners ; the intermediates change at from twenty to twenty-four months 

 and the middles at from thirty to thirty-six months. It will be noticed that this 

 order of appearance of permanent teeth is the reverse of that of the horse, 

 cow, and sheep, as it commences at the corners and works toward the center. 



