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THE VOYAGE OF H.M.S. CHALLENGER. 



have in every case clear proof that muscles when absent are lost by fusion (as for example 

 the Hare, the Fox-Bat, the Bathyergus, the Cape-Mouse, &c. &c). 



If we study the subjoined tabular views of the intrinsic pedal muscles in mammalia, 

 a considerable amount of light is thrown upon the relations of the different layers to 

 each other. We notice — (1) that the intermediate group is the most constant of the three 

 layers ; (2) that the dorsal layer is the least constant, and the most variable, in several 

 cases being wholly unrepresented ; (3) that there is a striking tendency to fusion between 

 the members of the intermediate and dorsal groups of muscles ; and (4) that the plantar 

 muscles almost invariably remain distinct from the subjacent muscles. 



Intermediate Layer — Flexores Breves. (Table B.) 

 Pentadactylous Feet. 



