APPENDIX. 



INTRODUCTORY. 



OF THE ANIMAL KINGDOM IN GENEKAI,. 



SYSTEMS are conventional arrangements, to enable naturalists 

 the more easily to classify species, so that their identity may be 

 traced, and compared, and investigated. As new species were 

 discovered, the task of ascertaining them became so difficult 

 and uncertain, that the necessity of Systems was the more 

 apparent. Accordingly, systematic arrangement was practised 

 to a limited extent before the time of Linnaeus, but to him we 

 are indebted for the production of a new and compreliensive 

 classification. He reduced all natural objects into three great 

 divisions : these he called Kingdoms ; viz. the Animal, Vege 

 table, and Mineral Kingdoms. These kingdoms he divided intc 

 Classes, Orders, Genera, Species, and Varieties. 



A plurality of species constitute a genus, a variety of genera 

 an order, and several orders a class. When, therefore, an ob- 

 ject presents itself, with which we are totally unacquainted, our 

 lirst business is to consider what is the class to which it be- 

 longs : having ascertained this, we next compare it with the 

 characters of the orders ; and having determined to which it is 

 allied, we proceed to investigate its generic characters -. when 

 we have satisfied ourselves as to this, we come to the last and 

 most difficult point, namely, the discovery of its species ; which 

 often rests on very trivial distinctions. 



See an account of vai'ious systems, vol. I. p. 4.38, &c. 



The St/stema NnturcB of Linnaeus, laid the foundation on 

 which almost all succeeding systems have been built. He ar- 

 ranged the Animal Kingdom into six classes, as follow ;- 



IV. 2 o 



