159 



three first pre-molars are temporary, or milk teeth, while the anterior 

 pre-molars and true molars are permanent. 



371. Incisors and Tusks. — Two sharp-pointed teeth are to be 

 seen on both sides of each jaw at birth, with an open space in front, 

 and these are the temporary corner incisors and tusks. About the 

 fourth week the central temporary incisors make their appearance, 

 being well in wear b}' the seventh or eighth week, and about the 

 twelfth week the lateral temporary incisors are seen. Between the 

 seventh and eighth month, the corner incisors are replaced by 

 permanent teeth, which are well in wear at nine months, while the 

 permanent tusks are now making their appearance through the gum. 

 When the pig is twelve months old, the central temporary incisors are 

 replaced by permanent ones ; and when about eighteen months old, 

 the lateral permanent incisors take the place of the temporary teeth, 

 and the central incisors show signs of wear at their edges. 



372. Molars and Pre-Molars. — Between birth and up to four 

 weeks old three temporary pre-molars on each side of each jaw, 

 above and below, are seen, the second and third coming through before 

 the first. The fourth tooth or first permanent molar and the anterior 

 pre-molars make their appearance between the fifth and sixth month 

 and are well up at the ninth month. From ten to twelve months 

 the fifth tooth or second permanent molar is seen, and about three 

 months after (15 months old) the three first temporary pre-molars are 

 shed, and permanent teeth take their place, while between the seven- 

 teenth and eighteenth month the sixth tooth and last permanent molar 

 is forward. After this the teeth wear and become dark in colour. 

 Dental derangements in pigs are, however, of rare occurrence, and 

 veterinary aid is seldom or never required. 



373. For further information on the subject of the dentition of the 

 horse, cow, sheep, and pig, the reader is referred to Prof. Sir Geo. 

 Brown's pamphlet — " Dentition and Age of the Animals of the Farm." 

 I may add that I have found this little work very accurate. 



