CuAV. II. ORDERS AMONG ANIMALS. 151 



and families are introduced in gome classes,^ only orders are noticed in others,^ 

 and even some exhibit only a succession of genera under the head of their class, 

 without any further grouping among them into orders or families.^ Other classi- 

 fications 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 Si/stema Naturce of Linnaeus, who first introduced in Zoology that 

 kind of groups, and the works of Cuvier, in which orders are frequently charac- 

 terized with unusual precision, and it has appeared to me that the leading idea 

 prevailing everyAvhere respecting orders, where these groups are not admitted at 

 random, is that of a definite rank among them, the desire to determine the rela- 

 tive 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 Linnaeus, 

 is called by him Priniates, 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 everywhere, the same vagueness in the definition of the diflxirent 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 difler- 

 ent degrees of complication of their structure, within the limits of the classes. 

 As such I would consider, for instance, the Actinoids and Halc^'onoids in the class 

 of Polypi, as circumscribed by Dana; the Hydroids, the Discophorte, and the Cte- 



* In tlie classes Manimali.i, Birds, R('])til('s, .and ^ The classes Eoliinoderms, Acaleplis, and Infu- 



Fishes, Cuvier di,stinf;iiislies mostly families as well soria, arc divided into orders, but without families. 



as orders. In the class of Mammalia, some orders ' Such are his classes of Cephalopods, Pteropods, 



number no families, whilst others are divided into Brachiopods, and Cirripcds (Cirrhopods.) Of the Ce- 



tribcs instead of tainilies. In the class of Gastcropods, phalopods, he says, however, they constitute but one 



Annelids, Intestinal Worm~, and Polyps, some of the order (Ri'gn. An. vol. 3, p. 11), and, p. 22, he calls 



orders only are divided into families, while the larger them a family, and yet he distinguishes them as a 



number are not. class, p. 8. 



