45 



Sheep and goats do not change their horns : one 

 year, therefore, being counted for the point, and an 

 additional year for each circle they prefent around 

 them, furnifhes the obferver with their ages. 



Dogs have no exaft criterion of their age ; but 

 their habits of domeftication enable us to judge 

 with confiderable certainty relative to it. At about 

 four years the teeth lofe their points, and gain a 

 furface, which increafes as the age advances; they 

 likewife become lefs white, and more uneven ; and 

 frequently by picking of bones one or more are lofl. 

 At feven or eight the hair about the eyes becomes 

 (lightly grey, which gradually extends over the face; 

 but it is not till ten, eleven, or twelve years, that 

 the eyes lofe their luftre : whenever that takes place,^ 

 the dog breaks faft, though many dogs laft fifteen, 

 fixteen, or feventeen years, and I have feen a mo- 

 ther and fon, vigorous at twenty and twenty-one 

 years. 



The age of horfes is alfo gained by a knowledge of 

 the appearances their body puts on at different pe- 

 riods : as they become old, their eyes fink, their 

 muzzles turn white or grey, and their eye-pits be- 

 come hollow ; but this fo much depends on their 

 previous ufage, that the exa6l age cannot be gained 

 from an attention to any of thefe appearances : we 

 therefore have recourfe to the teeth, which furnifli 

 certain alterations in their appearance every year in 



