430 GLAbSlFIGATION. 



that minerals and the elemental substances can be thus 

 arranged. In this case there is of course no relation to 

 genealogical succession, and no cause can at present be 

 assigned for their falling into groups. But with organic 

 beings the case is different, and the view above given 

 accords with their natural arrangement in group under 

 group; and no other explanation has ever been attempted. 



Naturalists, as we have seen, try to arrange the species, 

 genera and families in each class, on what is called the 

 Natural System. But what is meant by this system? 

 Some authors look at it merely as a scheme for arranging 

 together those living objects which are most alike, and 

 for separating those which are most unlike; or as an 

 artificial method of enunciating, as briefly as possible, gen- 

 eral propositions — that is, by one sentence to give the char- 

 acters common, for instance, to all mammals, 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 in- 

 genuity 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 knowledge. Expressions such as that famous one 

 by Linnaeus, which we often meet with in a more or less 

 concealed 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 classifica- 

 tions 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 classifications. 



Let us now consider the rules followed in classification, 

 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 general 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 deter- 



