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BEGINNERS' ZOOLOGY 



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Fig. 342. — Foot of Bear 

 {Plantigrade). 



eaten. The feet vary according to use in obtaining food 

 or escaping from enemies. This will explain the differ- 

 ence in the length of legs of lion 

 and horse, and of the forms of 

 the teeth in cat and cow. Make 

 a careful study of the teeth and 



the limbs as shown in the figures 

 and in all specimens accessible 

 Write out the dental formulas as 

 indicated at the top of page 194. The numerals above the 

 line show the number of upper teeth, those below the line 

 show the number of lower teeth, in one half of the jaw. 

 They are designated as follows : I, incisors ; C, canine ; 

 M, molars. Multiplying by two gives the total number. 

 Which skulls in the chart have the largest canines ? 

 Why ? The smallest, or none at all ? Why ? Compare 

 the molars of the cow, the hog, and the dog. Explain 

 their differences. In which skulls are some of the molars 

 lacking ? Rudimentary ? Why are the teeth that do not 

 touch usually much smaller than those that do? 



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Fjcj. 343. — Polar Bear ( C'rsus maritimus). 



