DESCRIPTIVE TEEMS. 5 



plane. The words anterior and posterior, superior and inferior, and several others 

 indicating position, are employed in human anatomy strictly with reference to the 

 erect posture of the body. But now that the more extended study of comparative 

 anatomy and embryonic development is largely applied to the elucidation of the 

 human structure, it is very desirable that descriptive terms should be sought which 

 may without ambiguity indicate position and relation in the organism at once in. 

 man and animals. Such terms as dorsal and ventral, neural and visceral, cephalic 

 and caudal, central and peripheral, proximal and distal, axial and appendicular, pre- 

 axial and postaxial, are of this kind, and ought, whenever this may be done con- 

 sistently with sufficient clearness of description, to take the place of those which are 

 only applicable to the peculiar attitude of the human body, so as to bring the 

 language of human and comparative anatomy as much as possible into conformity. 

 In many instances, also, precision may be obtained by reference to certain fixed 

 relations of parts, such as the vertelral and sternal aspects, the radial and ulnar, and 

 the tibial and fibular borders, the flexor and extensor surfaces of the limbs, and 

 similarly in other parts of the body. 



