of the Animals of the Farm. 



13 



temporary incisors, and, if necessary, to refer to the molar teeth, 

 in order to avoid such embarrassing blunders. 



Under ordinary circumstances it will be more frequently 

 necessary to distinguish between a yearling and a two-year-old, 

 than between a one-year-old and a five, and it fortunately happens 

 that at the age of two years another molar, the fifth in situation, 

 is in the mouth, and may be at once distinguished by its recent 

 appearance. Soon after eighteen months the fifth molar begins 

 to protrude through the gum, and by the termination of the 

 second year is level with the other molars, as shown in Fig. 8 

 (p. IG), so that any doubt which may remain after an inspection 

 of the incisors may be settled by reference to the condition of 

 the molars. 



Fig. 5. 



-Incisors of Colt at six months. 



It will be observed in the figure just referred to that the 

 surfaces of four molars are worn level, while the points of the 

 new tooth, the fifth in position, are rounded, excepting a small 

 portion at the inner side of the tooth, which shows the eflfects of 

 attrition, but only to a slight extent. 



The incisor teeth at two years of age have their tables per- 

 fectly formed as a rule ; but, in some instances, the corner teeth, 

 although they have lost their shell-like character, still have a 

 portion of the posterior edge untouched, as shown in the illus- 

 tration of the mouth of a two-year-old filly (Fig. 9, p. 17). 



Between two and three years of age the central temporary 

 incisors of the horse are changed for permanent teeth, and the 

 different phases of the change are sufficiently well defined to 



