22 ZOOLOGICAL PHILOSOPHY 



to insects, the entomology of Fabricius presents a special schematic 

 classification. All the progress made in recent times by the philo- 

 sophy of natural science has been necessary, in France at least, to carry 

 the conviction that the natural method should be studied. Our 

 classifications should conform to the exact order found in nature, 

 for that order is the only one which remains stable, independent of 

 arbitrary opinion, and worthy of the attention of the naturalist. 



Among plants, the natural method is extremely difficult to 

 estabhsh, on account of the obscurity prevailing in the character 

 of the internal organisation of these living bodies, and of the differences 

 presented by plants of different famihes. Since the learned observa- 

 tions of M. Antoine-Laurent de Jussieu, however, a great step has 

 been made in botany in the direction of the natural method ; many 

 families have been constituted with direct reference to their affinities ; 

 but the general position of all these famihes among themselves, and 

 consequently of the whole order, remains to be determined. The fact 

 is that we have found the beginning of that order ; but the 

 middle, and especially the end, are still at the mercy of arbitrary 

 opinion. 



The case is different with regard to animals ; their organisation 

 is much more pronounced, and presents different systems that are easier 

 to grasp. The work has, therefore, in their case made greater pro- 

 gress ; as a result, the actual order of nature in the animal kingdom 

 is now sketched out in its main outhnes in a stable and satisfactory 

 manner. It is only the boundaries of classes and their orders, of 

 famihes and genera, that are still abandoned to arbitrary opinion. 



If schematic classifications are still found among animals, these 

 classifications are only minor, since they deal with objects belonging 

 to one class. Thus, the hitherto received classifications of fishes and 

 birds are stiU schematic classifications. 



With regard to living bodies, the farther one descends from the 

 general to the particular the less constant become the characters 

 serving to determine affinities, and the more difficult to recognise 

 is the actual order of nature. 



Classes. — The name class is given to the highest kind of general 

 divisions that are established in a kingdom. The further divisions 

 of these receive other names : we shall speak of them directly. The 

 more complete is our knowledge of the affinities between the objects 

 composing a kingdom, the better and more natural are the classes 

 estabhshed as the primary divisions of that kingdom, so long 

 as attention has been paid to recognised affinities in forming them. 

 Nevertheless, the boundaries of these classes, even the best of them, 

 are clearly artificial ; they will therefore continue to undergo 



