GENERAL INTRODUCTION. 



ON THE PRINCIPLES OF ZOOLOGY. 



Biology is that branch of scientific inquiry which 

 undertakes to investigate the nature and relations 

 of living bodies. It is the object of this science, 

 by a careful study of the several beings of which 

 the organic world is composed, to ai-rive at a 

 knowledge of those general " laws " by which it is 

 governed. 



Every living being may be regarded from two 

 points of view, which it is necessary to distinguish 

 clearly from one another. The first of these ex- 

 hibits to us living beings as possessing definite 

 forms, which, in most instances, are found to be 

 made up of a number of dissimilar parts or organs ; 

 while the second takes cognisance of the vital 

 actions ox functions which those organs perform. 

 That department of Biology which determines 

 the former is termed Morphology; that which 

 investigates the latter Physiology, Hence the 



