THE CHARACTERS FURNISHED BY THE TEETH. 653 



It is especially at the end of this period that the observer must 

 exercise his perception and judgment in giving to all the variations of 

 the wear their proper value, particularly that of the corners and the 

 superior incisors. He will see, little by little, the free portion of the 

 pincers diminishing in length, their necks insensibly protruding above 

 the gums, and their color assuming a brownish hue. As they are 

 pushed out they become loose, movable, break off in fragments, and 

 naturally fall out, preparatory to being replaced by the permanent teeth. 

 This falling out will mark the third period of the life of the horse. 



Third Period. — Eruption of the Permanent or Adult In- 

 cisors. — The eruption of these teeth commences at the age of two and 

 one-half years and terminates at that of five years. 



About Two and One-half Years. — The successive shedding 

 of the milk pincers, the tumefaction of the gums at their level, and 

 the appearance of the anterior border of the one or the other permanent 

 pincers usually begin in the superior jaw ; in six weeks or two months 

 their evolution is completed. 



Rising Three Years. — This expression indicates that the colt 

 has not yet attained its third year, but that it is closely approaching 

 this age. 



In the superior jaw the adult pincers have perforated the gums 

 and are at the point of reaching the level of the milk intermediates ; 

 in the inferior jaw their borders and sometimes a variable portion of 

 the crown emerge from the gums. In all cases these teeth are unworn. 

 The milk intermediates appear constricted at their base and much worn 

 off; as to the corners, the wear involves their external border. (Plate 

 XII.) 



Three Years. — The animal has now completed his third year, 

 and his jaws present four permanent pincers well emerged through the 

 gums, whose surface of friction is found at the same level as that of 

 the neighboring teeth. By carefully examining the mouth, the pres- 

 ence of the incisors of the second dentition can now be immediately 

 recognized. By their greater volume, their slightly-square form, their 

 deeper color, and the groove on their anterior face they can be clearly 

 differentiated from the others, always constricted at their base, smaller, 

 more convex, whiter, and not grooved in front. We must also take 

 cognizance of the time of the year and the race in fixing the age of 

 three years. Thoroughbred colts attain it in the month of January, 

 wdiile those of the common races, whose birth takes place later, — " in 

 the spring-time, in the grass," as it is called, — will reach this age only 

 in the months of March, April, or May. 



