150 ESSAY ON CLASSIFICATION. Part I. 



same manner do genera differ more or less one from the other, even in the same 

 family; and such inequality, and not an equable apportionment, is the norm through- 

 out nature. In classes, it is not only exhibited in the variety of their forms, but 

 also, to an extraordinary extent, in their numbers, as, for instance, in the class of 

 Insects compared to that of Worms or Crustacea. The primary divisions of the ani- 

 mal kingdom differ in the same manner one from the other. Articidata are by far 

 the most numerous branch of the whole animal kingdom ; their number exceeding 

 greatly that of all other animals put together. Such facts are in themselves sufficient 

 to show how artificial classifications must be Avhich admit only the same number 

 and the same kind of divisions for all the types of the animal kingdom. 



SECTION III. 



ORDERS AMONG ANIMALS. 



Great as is the discrepancy between naturalists respecting the number and limits 

 of classes in the animal kingdom, their disagreement in regard to orders and fiimilies 

 is yet far greater. These conflicting views, however, do not m the least shake 

 my confidence in the existence of fixed relations between animals, determined by 

 thoughtful considerations. I would as soon cease to believe in the existence of 

 one God, because men worship Him in so many different ways, or because they 

 even worship gods of their own making, as distrust the evidence of my own senses 

 respecting the existence of a preestabhshed and duly considered system in natiu-e, 

 the arrangement of which preceded the creation of all things that exist. 



From the manner in which orders are generally characterized and introduced 

 into our systems, it would seem as if this kind of groups were interchangeable 

 with famHies. Most botanists make no difference even between orders and families, 

 and take ahnost universally the terms as mere synonyms. Zoologists have more 

 extensively admitted a difference between them, but while some consider the orders 

 as superior, others place families higher; others admit orders without at the same 

 tune distinguishing fanoUies, and vice versa introduce families into their classification 

 without admitting orders ; others stUl admit tribes as intermediate groups between 

 orders and families. A glance at any general work on Zoology or Botany may 

 satisfy the student how utterly arbitrary the systems are in this respect. The 

 R^gm animal of Cuvier exhibits even the iniaccountable feature, that whUe orders 



