Chap. XIV.] CLASSIFICATION. g05 



or as an artificial method of enunciating, as briefly as 

 possible, general propositions, — that is, by one sentence 

 to give the characters common, for instance, to all mam- 

 mals, by another those common to all carnivora, by 

 another those common to the dog-genus, and then, 

 by adding a single sentence, a full description is given 

 of each kind of dog. The ingenuity and utility of this 

 system are indisputable. But many naturalists think 

 that something more is meant by the Natural System; 

 they believe that it reveals the plan of the Creator; 

 but unless it be specified whether order in time or space, 

 or both, or what else is meant by the plan of the Creator, 

 it seems to me that nothing is thus added to our knowl- 

 edge. Expressions such as that famous one by Lin- 

 naeus, which we often meet with in a more or less con- 

 cealed form, namely, that the characters do not make 

 the genus, but that the genus gives the characters, seem 

 to imply that some deeper bond is included in our classi- 

 fications than mere resemblance. I believe that this 

 is the case, and that community of descent — the one 

 known cause of close similarity in organic beings — is 

 the bond, which though observed by various degrees of 

 modification, is partially revealed to us by our classifica- 

 tions. 



Let us now consider the rules followed in classifica- 

 tion, and the difficulties which are encountered on the 

 view that classification either gives some unknown plan 

 of creation, or is simply a scheme for enunciating gen- 

 eral propositions and of placing together the forms most 

 like each other. It might have been thought (and 

 was in ancient times thought) that those parts of the 

 structure which determined the habits of life, and the 

 general place of each being in the economy of nature. 



