Chap. XIII. 
CLASSIFICATION. 
413 
genera descended from (I). So tliat we here have many 
species descended from a single progenitor grouped into 
genera; and the genera are included in, or subordinate to, 
sub-families, families, and orders, all united into one class. 
Thus, the grand fact in natural history of the subordi^ 
nation of group under group, which, from its familiarity, 
does not always sufficiently strike us, is in my judgment 
explained. 
Naturalists 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 to¬ 
gether those living objects which are most alike, and for 
separating those which are most unlike; or as an artificial 
means for enunciating, as briefly as possible, general pro¬ 
positions,—that is, by one sentence to give the charac¬ 
ters common, for instance, to all mammals, by another 
those common to all carnivora, by another those com¬ 
mon to the dog-genus, and then by adding a single sen¬ 
tence, 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 specifled whether 
order in time or space, or what else is meant by the plan 
of the Creator, it seems to me that nothing is thus added 
to our knowledge. Such expressions as that famous one 
of Linnaeus, and which we often meet with in a more or 
less concealed form, that the characters do not make the 
genus, but that the genus gives the characters, seem to 
imply that something more is included in our classifica¬ 
tion, than mere resemblance. I believe that something 
more is included; and that propinquity of descent,—the 
only known cause of the similarity of organic beings,— 
is the bond, hidden as it is by various degrees of modifi- 
