CLASSIFICATION. 165 



animal and vegetable kingdoms are systematically 

 divided into certain groups, and these into successively 

 smaller groups until we arrive at the species. These 

 groups are founded upon the possession of certain 

 points of resemblance by their members, forming the 

 distinguishing characters, and their names are signi- 

 ficant and definite. They usually run as follows, the 

 larger and higher groups standing first in order : 

 Kingdoms, Subkingdoms, Classes, Orders, Families, 

 Tribes, Genera, and Species. But it must be observed 

 that the term species has a different value from that 

 of the other terms ; for the individuals of which the 

 species consist are not only related by resemblance 

 of structure, but also by their origin being supposed 

 to have derived their origin from a parent of original 

 creation ; while the other groups have, as far as we 

 know, no other relation than that of similarity of 

 structure. 



It is obvious that the characters of the various 

 groups might be founded upon peculiarities of any 

 kind. But on this point two methods must be speci- 

 ally distinguished, in one of which the groups are 

 founded upon the sum of all the peculiarities, while 

 in the other they are based upon the structure of 

 single parts or organs. In the former case the system 

 is called natural, in the latter artificial. And while the 

 latter often brings together beings which have per- 

 haps but one or two points of resemblance, and sepa- 

 rates others which are closely related, the former 

 associates those which are really and naturally similar. 



All the groups have special names, so that they 

 may be referred to and spoken of as in the case of 

 common things ; the names being composed of Greek 

 or Latin words, so that they may be intelligible to all 

 nations ; and as these are dead languages, they will 

 remain good for all time. 



In mentioning the name of an animal or plant, the 

 name of the genus is always used with that of the 



