140 



ELEPHANTS 



LOWER 

 > Molcur-s 



3 4 5 6. 7 



Molars 



UPPER 



LOWER 



FIG. 15. The teeth in the upper and lower jaw-bone of the common 

 pig drawn from photographs. A and B represent the right half of 

 the lower jaw (A) and the right half of the upper jaw (B) seen in 

 horizontal position. Inc. are the incisors or chisel-like front teeth, 

 three in number, in each half of each jaw and marked i, 2, 3. C 

 marks the canine or dog-tooth, which here grows to be a large tusk. 

 The molars, " grinders," or cheek teeth are marked I to 7. Figs, 

 c and D give a side view of the left halves of the upper (c) and of 

 the lower jaw-bone (D), with the teeth in place. The bone has been 

 partly cul away so as to show the fangs or roots of the teeth, which 

 are double in the molars, and even three-fold in molar No. 7. The 

 explanation of the lettering is the same as that given for figs. A 

 and B. The letter p in Fig. B points to a "foramen " or hole in 

 the upper jaw-bone. These drawings are introduced here as show- 



