200 



ANATOMY OF THE WOOD RAT 



TABLE 1— Continued 



addition, many of these muscles play a relatively minor role 

 in the economy of the animals. Hence, a more detailed 

 consideration of each point of difference is hardly worth 

 while; but certain trends that seem to be apparent should 

 be discussed. 



Directly correlated with myological variations are osteo- 

 logical differences, or at least many of them. Certain of 

 the latter are undoubtedly attributable to causes other than 

 the direct influences of the muscles. There are certain 

 hereditary characters of one sort or another, such as long- 

 face or broad-face in man, which vary irrespective of the 



