172 STUDY OF NATURAL HISTORY., 



of plants and flowers. It is in the investigation of 

 these beings, that some acquaintance with compara- 

 tive anatomy is essential. Having now sufficiently 

 discussed the relative value apparently belonging 

 to different parts of the structure of an animal, 

 little need be said on its composition. This, in fact, 

 is the province of the chemist, whose business it is 

 to analyse, not the form, but the elements of which 

 that form is composed. Such considerations, no less 

 than those belonging to internal structure, are 

 essential to the full and complete knowledge of an 

 organised being ; but, whenever such a being can 

 be defined with sufficient accuracy by more simple 

 means, a redundancy of knowledge and a compli- 

 cation of characters are clearly to be avoided. 



(115.) 2. Let us now pass to the second head of 

 our subject : viz., the properties of an animal. It 

 is evident, to an attentive observer, that the innu- 

 merable beings composing the animal creation are 

 destined to perform different offices therein ; and 

 that they are not only endowed with forms adapted 

 to such offices, but with instincts for carrying them 

 into effect. Our attention is naturally directed, in 

 the first instance, to their forms, because they may 

 be understood and recognised long before we be- 

 come acquainted with the designs for which such 

 forms were created. The properties, therefore, of 

 an animal consist, first, in its habits or instincts ; 

 and secondly, in the mode in which the . qualities 

 contribute to the general economy of nature. 



(116.) The economy of nature, — *that is to say, 

 the harmonious adjustment of all created things, — is 

 preserved by the efforts of all, instinctively directed, 



