354 PRIMARY FACTORS OF ORGANIC EVOLUTION. 



transverse. The successive increase in depression in 

 the bones of the feet with the advance of time is to be 



a'g. 



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 X ' a 



t? M 

 -* M 



fe>S,"l 



^ (D 

 <o" if 



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n ~ . 

 3. 2. S: 



P 



Ms 



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n o 



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 3 ^ ft 



s 



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most readily seen in the order Amblypoda, where we 

 pass from Pantolambda to Coryphodon and Uintathe- 



