206 AGE OF ANIMALS. 



" At eighteen years the sides of the triangle of the middle 

 nippers are longer at the sides of the teeth than in front. 



" At nineteen years the middle nippers become flattened 

 from side to side and long from front to rear. 



" At twenty years the second pair assume the same form. 



" At twenty-one years all of the teeth of the lower jaw 

 have become flattened from side to side ; the greatest diam- 

 ter having become exactly the reverse of what it was in 

 youth." 



TO FIND THE AGE OF CATTLE. 



In the cow the horn is often regarded as affording, by the 

 number of its rings, a criterion of the animaFs age. The 

 horn of a heifer remains smooth or unprotuberant till the 

 expiration of the second year of its life. A circle of thicker 

 matter, or sort of horny button then begins to be formed, 

 which is completed in another year ; the next year this circle 

 or button moves from the head, or is impelled by the cylin- 

 dric growth of the horn, and another circle or button begins 

 to be formed, which after another twelve-month is also im- 

 pelled outward, and so on year after year of the whole life 

 of the animal, so that by counting the number of rings on 

 the cow's horns, and adding 2 to their number, its age is 

 arrived at. 



The rings on the ~buWs horns do not begin to appear until 

 he is five years old, so that to arrive at his age we must add 

 5 to the number of rings. The horn of the ox is so very 



