158 



368. Incisors.— From the birth of the lamb to the end of the 

 fourth week the six temporary incisors and the two canine or 

 corners are cut, also the first, second, and third temporary pre-molars, 

 and at twelve months the crowns of the incisors are well worn, the 

 teeth being small and far apart. At about 15 months the two central 

 temporary incisors are shed and two permanent teeth take their place. 

 About 22 months the middle laterals (incisors) are replaced by two 

 more permanent teeth and the animal now has four broad teeth. At 

 two years or two years and three months the permanent laterals 

 make their appearance and the sheep shows six broad teeth, and 

 at three years old the corner or canine permanents are up. 



369. Molars. — About the age of three months the first permanent 

 molar, or fourth tooth, makes its appearance ; at nine months the 

 fifth tooth, or second permanent molar, is seen, and at eighteen 

 months the sixth tooih, or last permanent molar, comes into view; 

 and from twenty to twenty-two months old the first and second 

 temporary pre-molars, above and below, on each side, are replaced by 

 permanent teeth, and at about two years old the third temporary is 

 shed and a permanent tooth takes its place, the sheep now having 

 twenty-four permanent molar teeth, viz., f pre-molars f molars on 

 each side, and in some early mouths possibly six permanent incisors. 

 The permanent teeth, both incisors and molars, are much larger and 

 darker in colour than the temporary ones. 



THE PIG. 



370. The dentition of the pig differs a good deal from that of the 

 cow and sheep. Pigs have six incisor teeth above and below in front of 

 the jaws ; behind the corner teeth on each side in the upper and lower 

 jaws are the canine teeth, or tusks ; and between the latter and the 

 first pre-moiar teeth, one on each side, both above and below, are 

 the anterior pre-molars, while there are six molars on each side, above 

 and below, viz., three pre-molars and three molars. This makes a 

 full total of 44 teeth, i.e., 12 incisors, 4 canines, 4 anterior pre-molars, 

 12 pre-molars, and 12 molars (pnr. 345). The incisors, canines, and 



