60 ZOOLOGICAL PHILOSOPHY 



groups of objects ; and this knowledge compels us to conform to her 

 order. 



The first result obtained from the use of affinities in placing the group» 

 in a general scheme is that the two extremities of the order must be 

 occupied by the most dissimilar beings, since they are the most distant 

 from one another from the point of view of affinities, and consequently 

 of organisation. Hence it follows that if one of the extremities of 

 the order is occupied by the most perfect of living bodies, having the 

 most complex organisation, the other extremity of the order must 

 necessarily be occupied by the most imperfect of living bodies, namely, 

 those whose organisation is the simplest. 



In the general arrangement of known plants according to the natural 

 methods, that is according to affinities, only one extremity is thoroughly 

 known ; and that is occupied by the cryptogams. If the other ex- 

 tremity is not determined with equal certainty, it is due to the fact 

 that our knowledge of plant organisation is much less advanced than 

 our knowledge of the organisation of a great number of known 

 animals. Hence it follows that in the case of plants we have as yet 

 no certain guide to the affinities between the large groups, as we have 

 to those among genera and famiUes. 



The same difficulty does not exist in the case of animals, and both 

 extremities of their general series are thus definitely fixed ; for as long 

 as importance is attached to the natural method, and hence to 

 affinities, the mammals will of necessity occupy one extremity of 

 the order, while the infusorians will be placed at the other. 



For animals then, as well as for plants, there exists in nature an 

 order arising, Hke the objects which it calls into existence, from powers 

 conferred by the Supreme Author of all things. Nature is herself 

 only the general and immutable order created everywhere by this 

 Sublime Author ; she is the sum total of the general and special laws 

 to which that order is subject. By these powers, which she continues 

 unchangeably to make use of, she has given and still continues to give 

 existence to her productions ; she is incessantly varying and renewing 

 them, and thus maintains everywhere the entire order which results. 



We were obUged to recognise this order of nature in each kingdom 

 of living bodies ; and we are already in possession of various parts 

 of it, in our better constituted famiUes and genera. We shall now 

 see that in the animal kingdom it is established in its outUnes in a 

 way that leaves no scope for arbitrary opinion. 



But the great number of divers animals that we have come to know, 

 and the brilUant light shed by comparative anatomy on their organisa- 

 tion, now place it in our power definitely to draw up the general Ust 

 of all known animals, and to assign definitely the rank of the main 



