CLASSIFICATION. 503 



experiment upon the Kind itself; no inference respecting its properties 

 from the properties of things not connected with it by Kind, goes for 

 more than the sort of presnmption usually characterized as an analogy, 

 and generally in one of its fainter degrees. 



Since the common properties of a true Kind, and consequently the gen- 

 eral assertions which can be made respecting it, or which are certain to 

 be made hereafter as our knowledge extends, are indefinite and inexhausti- 

 ble; and since the very first principle of natural classification is that of 

 forming the classes so that the objects composing each may have the great- 

 est number of properties in common; this principle prescribes' that every 

 such classification shall recognize and adopt into itself all distinctions of 

 Kind, which exist among the objects it professes to classify. To pass over 

 any distinctions of Kind, and substitute definite distinctions, which, how- 

 ever considerable they may be, do not point to ulterior unknown differ- 

 ences, would be to replace classes with more by classes with fewer attri- 

 butes in common; and would be subversive of the Natural Method of 

 Classification. 



Accordingly all natural arrangements, whether the reality of the distinc- 

 tion of Kinds was felt or not by their f ramers, have been led, by the mere 

 pursuit of their own proper end, to conform themselves to the distinctions 

 of Kind, so far as these have been ascertained at the time. The species 

 of Plants are not only real Kinds, but are- probably, all of them, real lowest 

 Kinds, Infirase Species ; which, if we were to subdivide, as of course it is 

 open to us to do, into sub-classes, the subdivision would necessarily be 

 founded on definite distinctions, not pointing (apart from what may be 

 known of their causes or effects) to any difference beyond themselves. 



In so far as a natural classification is grounded on real Kinds, its grouj)s 

 are certainly not conventional : it is perfectly true that they do not depend 

 upon an arbitrary choice of the naturalist. But it does not follow, nor, I 

 conceive, is it true, that these classes are determined by a type, and not by 

 characters. To determine them by a type would be as sure a way of miss- 

 ing the Kind, as if we were to select a set of characters arbitrarily. They 

 are determined by characters, but these are not arbitrary. The problem 

 is, to find a few definite characters which point to the multitude of indefi- 

 nite ones. Kinds are Classes between which there is an impassable bar- 

 rier; and what we have to seek is, marks whereby we may determine on 

 which side of the barrier an object takes its place. The characters which 

 will best do this should be chosen : if they are also important in them- 

 selves, so much the better. When we have selected the characters, we 

 parcel out the objects according to those characters, and not, I conceive, 

 according to resemblance to a type. We do not compose the species Ra- 

 nunculus acris, of all plants which bear a satisfactory degree of resemblance 

 to a model buttercup, but of those which possess certain characters select- 

 ed as marks by which we might recognize the possibility of a common 

 parentage; and the enumeration of those characters is the definition of the 

 species. 



The question next arises, whether, as all Kinds must have a place among 

 the classes, so all the classes in a natural arrangement must be Kinds? 

 And to this I answer, certainly not. The distinctions of Kinds are not 

 numerous enough to make up the whole of a classification. Very few of 

 the genera of plants, or even of the families, can be pronounced with cer- 

 tainty to be Kinds. The great distinctions of Vascular and Cellular, Di- 

 cotyledonous or Exogenous and Monocotyledonous or Endogenous plants, 



