ORDERS AMONG ANIMALS. 229 



terizcd and introduced into our systems, it would seem 

 as if this kind of groups were interchangeable with fami- 

 lies. Most botanists make no difference at all between 

 orders and families, and take almost universally the terms 

 as mere synonyms. Zoologists have more extensively ad- 

 mitted a difference between them, but while some consider 

 the orders as superior, others place families higher ; others 

 admit orders without at the same time distinguishing 

 families, or vice versa introduce families into their classi- 

 fication without admitting orders ; others again admit 

 tribes as intermediate groups between orders and fami- 

 lies. A glance at any general work on Zoology or Botany 

 will satisfy the student how utterly arbitrary the systems 

 are in this respect. The Regne animal of Cuvier exhibits 

 even the unaccountable feature, that while orders and 

 families are introduced in some classes, 1 only orders are 

 noticed in others, 2 and some exhibit only a succession of 

 genera under the head of their class, without any further 

 grouping among them into orders or families. 3 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., and bear evidence upon their face that they 

 are made to suit preconceived ideas of regularity and 



1 In the classes Mammalia, Birds, 3 The classes Echinoderms, Aca- 



Reptiles, and Fishes, Cuvier mostly lephs, and Infusoria are divided into 



distinguishes families as well as orders, but without families, 



orders. In the class of Mammalia 3 Such are his classes of Cephalo- 



some orders number no families, pods, Pteropods, Brachiopods, and 



whilst others are divided into tribes Cirripeds (Chrhopods). Of the Ce- 



instead of families. In the class of phalopods, he says, however, they 



Gasteropoda, Annelids, Intestinal constitute but one order (Regn. An., 



Worms, and Polyps, some of the vol. 3, p. 11), and p. 22, he calls them 



orders only are divided into families, a family ; and yet he distinguishes 



while the larger number are not. them as a class, p. 8. 



