CHAPTER V 

 MYOLOGY 



PREFATORY NOTE 



In works on anatomy it is usual to have the osteological 

 portion precede the myological, but in the present instance 

 so much information on the muscles is included with the 

 descriptions of the bones that for the sake of convenience 

 the chapter on myology is placed first. 



It is, perhaps, unfortunate that no two works on myology 

 have ever employed the same arrangement of the muscles, 

 but this is inevitable with our present state of ignorance 

 regarding the group relationship of many muscles. To 

 assemble them by regions, save in the broadest sense, is 

 misleading and meaningless. As group relationship of 

 the muscles is established by their innervation one must 

 arrange them with this constantly in mind. It is always 

 found, however, that no inflexible rule can be followed, 

 and any arrangement now used must be largely theoretical 

 and ideahstic. In the present instance the arrangement 

 employed takes into consideration the probable basic 

 grouping of the muscles of mammals in general — not of the 

 wood rat in particular. This, at first glance, may not seem 

 to conform to the functional grouping presented on page 185 

 but closer attention will show that practically it does. 

 The more purely phylogenetic arrangement can not be 

 strictly logical in all instances, however. For instance, the 

 M. quadriceps surae is placed with the flexors of the lower 

 leg, although the soleus does not act as such but only as 

 an extensor of the foot. 



The neurology of the genus Neotoma was investigated 

 only to the extent necessary to establish the innervation of 



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