8 INTRODUCTION. 



its characters or peculiarities. The more numerous 

 the objects we have to distinguish, the greater must 

 be the accumulation of such distinctive characters, 

 so that accurately to distinguish any one object 

 from every other beside it would be found neces- 

 sary, without some more concise method, to enter 

 into a complete description of it. To obviate this in- 

 convenience, divisions and subdivisions have been in- 

 vented. Thus a certain number of objects, similar 

 to each other in general conformation, and differing 

 only in minor particulars, are arranged together, 

 and the gross is denominated a genus. 



To avoid the same inconvenience in distinguish- 

 ing the genera the operation is repeated, and the 

 genera which are assimilated to each other are, in 

 like manner, formed into an order, and these again 

 which border on each other constitute a class. In- 

 termediate subdivisions are also established when 

 necessary. The application of these several divi- 

 sions of classes, orders, and genera, to the animal 

 world, will be considered hereafter. They are em- 

 ployed in the mineral and vegetable, as well as in 

 the zoological division of natural history. 



This scale of divisions, of which the superior con- 

 tain the inferior, is what is called a svstem or me- 

 thod. It is, in some respects, a sort of dictionary, 

 wherein, from the properties of things, we proceed 

 to discover their names, thus forming the inverse 

 of ordinary dictionaries, wherein the names direct 

 us to the properties. 



But, if any proposed system or method be good, 



