INTRODUCTION 3 



indicate the more general matters of relative size 

 and position. The nomenclature ordinarily used 

 in standard anatomical literature has been fol- 

 lowed. The signification of the general terms of 

 direction is : 



Anterior toward the head. 



Posterior toward the tail. 



Dorsal toward the region of the back. 



Ventral toward the region of the belly. 



Lateral. ...'.... toward either side. 



Proximal toward the central axis of the body. 



Distal away from the central axis of the 



body. 



The terms right and left refer to the right and 

 left of the animal being dissected, and not neces- 

 sarily to the right and left of the dissector. 



