SNOUT OF THE PIG. 161 



the growth of the tusks or canine teeth. At four years, or 

 somewhat earlier, the upper canines begin to lift up the lip ; 

 at five they appear through the lips ; at six the canines of the 

 lower jaw come to display themselves out of the mouth, while 

 they take on a spiral form. The latter acquire a prodigious 

 size in old animals, particularly in the entire boar, and, as 

 they grow in length, they take on a curved form in an out- 

 ward and backward direction becoming often so crooked 

 as to require the file or nippers to restore a free motion to 

 the jaw. 



For what relates to the structure of the teeth in the pig, 

 enough may be gathered from what has been already stated 

 under the head of the teeth in the horse (p. 13 et seq.) 



Snout. A comparison between the face of the pig and that 

 of other animals shows that the object of the structure is to 

 give firmness and strength to the snout. The snout is the 

 implement with which the pig, in a state of nature, digs in the 

 ground for his food. 



In the pig the nasal bones are large and elongated ; they 

 extend as far as the anterior extremity of the ascending branch 

 of the intermaxillary or os incisivum ; they terminate by a 

 simple spongy point. The superior maxillary bone, properly 

 so called that is, to the exclusion of the os incisivum or in- 

 termaxillary consists essentially of a superior branch, more or 

 less vertical, and of an internal, horizontal, or palatine branch. 

 In the pig the superior maxillary is high posteriorly, extending 

 vertically downwards. The os incisivum, another name for 

 the intermaxillary, in the pig is long and broad. The facial 

 branches, by their upper and posterior extremity, touch the 

 external border of the nasal bones. The palate bones are 

 formed of a vertical branch and a horizontal branch, united 

 together at a right angle. The bones of opposite sides are 



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