THE CANID^, OR DOGS. 



261 



has in the upper jaw four premolars or ieeth that 

 have replaced the milk-teeth, and two molars. Of 

 the premolars the fourth Q) 4 )is remarkable owing 

 to its size, compressed form and sharp edge, also 

 by possessing an inner process in front ; this is the 

 carnassial or ' flesh-tooth.' Corresponding with it 



FIG. 48. Jaw of the Fox. After Huxley. 



below we have not the p*, but the first of the three 

 molars or grinders, m 1 . The connection and origin 

 of the different species of Dogs is determined by 

 the, in some cases, undistinguishable shades of 

 difference in the tubercles and processes, by the 



distances of these points from each other, and by 

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