368 PRINCIPLES AND METHODS OF PALAEONTOLOGY. 



of birds, of reptiles, of arapliibians, and of fishes; and if we select any 

 of these subordinate plans we find it a^ain modified so as to constitute 

 the plans of the minor subdivisions of these great assemblages. The 

 reptilian plan is modified in one way to form the plan of the turtle tribe, 

 in another to constitute that of the crocodiles, in another that of the 

 lizards, of the snakes, and so forth. And, in like manner, the common 

 plan of any great division of the animal kingdom is seen, in nature, to 

 be modified into a series of more and more altered and specialized plans, 

 each of which is common to the members of a progressively smaller sub- 

 division of the group, until at length we arrive at the smallest assem- 

 blage of beings which can be said to possess a particular common jjlan ; 

 or, in other words, which exhibits characters common to all its constitu- 

 ents, and not possessed by those of any other group. 



It is by reason of these singular relations among the forms of living- 

 beings that Avhat is termed a "natural classification" is possible. In the 

 ordinary business of life, whenever it is necessary to recollect and have 

 at command a multiplicity of objects, we "classify" those objects; we 

 arrange them in groups or packets distinguished by particular marks 

 and having a particular order. Thus it is that the merchant arranges 

 his wares, the librarian his books, the lawyer his papers; and the 

 imturalist, in like manner, would find it utterly impossible to grapple 

 with the details of the two or three hundred thousand distinct forms of 

 living beings, which are the object of his study, unless he could in some 

 way classify and arrange them. 



Now the aiui of classification may vary. Many persons imagine that 

 natural history is the knowledge of the names which have been affixed 

 to animals and plants by men of science; and the wish of such i^ersons 

 is to have a classification so contrived as to enable them, with the least 

 possible trouble, to ascertain what name has been affixed to an object, 

 or, better still, to determine that no name has been given to it, when 

 they have the satisfaction of baptizing it themselves. These " natural- 

 ists," necessarily, desire in a classification only a good index and diction- 

 ary of the names of animals and plants, and it matters not by what marks 

 they designate their groups so long as those marks are easily discovera- 

 ble and readily remembered. Thus, plants might be divided according 

 to the number of stamens in the flower, while animals might be classed 

 according to the number of their teeth, the shape and number of their 

 legs, &c. ; and arrangements of this kind, if skillfully made, might have 

 no small value and use in helping us to discover what animals and plants 

 are, and what are not known, but it is clear they would be purely arbi- 

 trary ; there would be no necessary relation between the members of the 

 sarious groups beyond the single point in which "they agree ; in other 

 words, the classification would be "artificial" and not "natural." 



But the low conception of the objects of the science of natural history, 

 from which such artificial classifications flowed, has given ifiace to other 

 and higher views, and with it all artificial systems have become exploded, 

 or relegated to their proper place as mere aids to the memory. The nat- 

 uralist of the present day, in fact, stands to him of the past in the relation 

 of a iSf iebuhr, a Hallam, or a Guizot, to the gossiping compiler ofuchroniquc 

 scandidciiscj or, at best, to a Froissart or a Burnett. Without despising 

 the importance of a knowledge of the names and habits of living beings, 

 he sees beyond this, and overruling it, a higher and a nobler aim — the 

 investigation of the laws of life, of the principles discoverable amid the 

 multiform structures of living beings, and of the relations in which they 

 stand to one another and to the surrounding universe. 



For such objects an artificial classification is useless, if not obstructive. 



