CHAPTER VIII. 



OF THE NATURAL ORDER OF ANIMALS, AND THE WAY IN WHICH 



i THEIR CLASSIFICATION SHOULD BE DRAWN UP SO AS TO BE 



IN CONFORMITY WITH THE ACTUAL ORDER OF NATURE. 



I HAVE already observed that the true aim of a classification of animals 

 should not be merely the possession of a list of classes, genera and species, 

 but also the provision of the greatest facihties for the study of nature 

 and for obtaining a knowledge of her procedure, methods and laws. 



I do not hesitate to say, however, that our general classifications of 

 animals up to the present have been in the inverse order from that 

 followed by nature when bringing her hving productions successively 

 into existence ; thus, when we proceed from the most complex to the 

 simplest in the usual way, we increase the difficulty of acquiring a 

 knowledge of the progress in complexity of organisation ; and we 

 also find it less easy to grasp both the causes of that progress and of 

 the interruptions in it. 



When once we have recognised that a thing is useful and indeed 

 indispensable for the end in view and that it is free from drawbacks, 

 we should hasten to carry it into execution although it is contrary 

 to custom. 



This is the case with regard to the way in which a general classi- 

 fication of animals should be drawn up. 



We shall see that it is not a matter of indifference from which end 

 we begin this general classification of animals, and that the beginning 

 of the order is not a mere matter of choice. 



The existing custom of placing at the head of the animal kingdom 

 the most perfect animals, and of terminating this kingdom with the 

 most imperfect and simplest in organisation, is due, on the one hand, 

 to that natural prejudice towards giving the preference to the objects 

 which strike us most or in which we are most pleased or interested ; 

 and, on the other hand, to the preference for passing from the better 

 known to what is less known. 



