OF ARTS AND SCIENCES. 95 



some of the Latreillean genera to Linne's time, and even to insist, for 

 the first time, upon the necessity of employing Plebeius and similar 

 words in a generic sense and of accrediting them to Linne. It may be 

 added that some of these subordinate names of Linne are used in what 

 I deem to be their true signification, as names of groups, in my Syste- 

 matic Revision. 



Other subsidiary principles, which are employed in this essay, should 

 be stated. A generic name founded upon that of any species intended 

 to be included therein, or of any synonyme of such species, must fall ; 

 and if any name falls, from this or from any other cause, it should be 

 dropped altogether in zoology. I have here adopted the views of 

 biologists who allow the repetition of names in its two departments 

 of zoology and botany, but no further. And no attempt has been 

 made to discover whether the older name (under which another may 

 fall) is in actual use or not, since in the ever-changing sentiment among 

 naturalists, of the generic limitation of groups, this is practically 

 impossible, and would lead to the instability of nomenclature. The 

 author, department, and date of publication of the older name before 

 which any generic appellation falls, has been given, whenever possible, in 

 order that any person may, if he choose, follow out any reference for 

 himself, here as elsewhere. If a species is designated as type of a 

 genus whose name cannot stand, it retains that significance when a new 

 generic name is proposed to supplant it. 



By thus calling the attention of naturalists to historical facts 

 (which they may interpret in any way they judge best), I hope to have 

 done something toward introducing some degree of fixity, logic, and 

 precision in the generic nomenclature of the group under consider- 

 ation. More perhaps than any other class of animals, unless we 

 except Mollusca, butterflies have suffered from the writings of un- 

 educated naturalists ; and it is impossible, such has become the multi- 

 plicity of names, to reduce to order the chaotic mass of facts, excepting 

 through their patient collation and chronological exposition. If other 

 facts are discovered by which the result is affected, they can at once be 

 brought into proper collocation ; if a wrong interpretation is given, 

 it is the more readily seen and pointed out. The method is clear and 

 precise, although tedious and painful in the extreme ; and such is the 

 interrelation of usage among certain names, and the heterogeneous 

 nature of others, as often to render the study very perplexing. The 

 result reached in some cases will surprise many entomologists, as it 

 has myself, and in not a few instances I would gladly see a logical way 

 out of the necessity of change among names which have had long 



