156 ESSAY ON CLASSIFICATION 



grouping among them into orders or families.^^ Other classifications 

 exhibit the most pedantic uniformity of a regular succession in each 

 class, of sub-classes, orders, sub-orders, families, sub-families, tribes, 

 sub-tribes, genera, sub-genera, divisions, sections, and sub-divisions, 

 sub-sections, etc., but bear upon their face that they are made to suit 

 preconceived ideas of regularity and symmetry in the system, and 

 that they are by no means studied from nature. 



To find out the natural characters of orders from that which really 

 exists in nature I have considered attentively the different systems 

 of Zoology in which orders are admitted and apparently considered 

 with more care than elsewhere, and in particular the Systema 

 Natiirce'^'^ of Linnaeus, who first introduced in Zoology that kind of 

 group, and the works of Cuvier, in which orders are frequently char- 

 acterized with unusual precision; and it has appeared to me that the 

 leading idea prevailing everywhere respecting orders, where these 

 groups are not admitted at random, is that of a definite rank among 

 them, the desire to determine the relative standing of these divisions, 

 to ascertain their relative superiority or inferiority, as the name order 

 adopted to designate them already implies. The first order in the first 

 class of the animal kingdom, according to the classification of Lin- 

 naeus, is called by him Primates, expressing, no doubt, his conviction 

 that these beings, among which Man is included, rank uppermost in 

 their class. Blainville uses here and there the expression of "degrees 

 of organization," to designate orders. It is true Lamarck uses the 

 same expression to designate classes. We find therefore here, as every- 

 where, the same vagueness in the definition of the different kinds of 

 groups adopted in our systems. But if we would give up any arbitrary 

 use of these terms and assign to them a definite scientific meaning, 

 it seems to me most natural and in accordance with the practice of 

 the most successful investigators of the animal kingdom, to call orders 

 such divisions as are characterized by different degrees of complica- 

 tion of their structure, within the limits of the classes. As such I 

 would consider, for instance, the Actinoids and Halcyonoids in the 

 class of Polypi, as circumscribed by Dana; the Hydroids, the Disco- 



"Such are his classes of Cephalopods, Pteropods, Brachiopods, and Cirripeds (Cir- 

 rhopods). Of the Cephalopods, he says, however, they constitute but one order, and he 

 calls them a family, and yet he distinguishes them as a class. Regne animal (2d ed.), 

 111,8, 11,22. 



" [Leiden (1735); 12th ed., 3 vols., Stockholm (1766-1768).] 



