MEMOIR OF ARJSTOTUE. 103 



enemies, and explains the ordinary means by which 

 each ctess provides for its preservation and defence. 

 In taking this wide survey of animated nature, 

 Aristotle pretends not to exhaust its infinitely va- 

 ried branches, for these defy the grasp of science ; 

 but in the multitude of important and well as- 

 certained facts which he relates, and which is in- 

 comparably greater than will be found in any work 

 of equal compass, it is his main purpose to illustrate 

 the general heads above mentioned, and to expound 

 the properties or affections common to the greatest 

 or most distinguished portion of the whole animal 

 kingdom. To these general heads or common pro- 

 perties, he constantly has respect in the historical 

 part of the work ; so that his minutest observations 

 respecting the humblest and least perfectly organized 

 animal are often found to elucidate or confirm some 

 important law of the animal economy *. His sys- 

 tem, inasmuch as the range of his observation was 

 limited, was necessarily defective. The world created 

 by the microscope had not any existence for the phi- 

 losophers of antiquity. By means of this and other 

 inventions, the chain of being has been extended far 

 beyond what the unassisted eye could possibly have 

 reached. Our wider acquaintance with the different 

 regions of the globe, has increased our knowledge 

 of the animal kingdom ; and our superiority in ex- 

 perimental science has thrown new light on the struc- 

 ture and functions of the animal economy. The ap- 



* Gilliea's New Analysis of Aristotle's Works, voL i. 

 p, 146. 



