140 JH^ ANIMAL KINGDOM 



he might describe them and give them a name. This description would 

 have to be carelul and precise, so that others could use it. If this zoologist 

 were not a specialist on li/ards, he probably would be unable to make 

 either an adequate search of the literature or a proper description of his 

 new animals, and would turn the job over to an appropriate specialist. 



41. The Binomial System 



Although the beginning student cannot, perhaps, appreciate the 

 extreme exactness required in a proper description, he can understand 

 that the naming of a new species must follow a set of rules. Scientific 

 names are made of two words, the name of the genus, a group containing 

 several closely similar kinds of organisms, and the name of the species, 

 the particular kind in that genus. This binomial system performs a 

 function similar to that of naming people, in which the use of both 

 a surname and a given name facilitates the recording and cataloguing 

 of a population. The generic name is always a noun, such as Canis (dog, 

 Perca (perch) or Hymenolepis (a genus of tapeworms), and is always 

 capitalized. The specific name is (in zoology) never capitalized. It may 

 be an adjective (such as Wolf gray), a noun in apposition (such as Cat 

 lion), a noun in the genitive (such as Mouse of California), or any of 

 several other possibilities, always of course in Latin. The name of the 

 species serves only to identify the particular species within its genus. 

 Hence, the same specific name may appear many times in the animal 

 kingdom, providing each time it is in a different genus (Cylichna alba, 

 a white snail, Fredericia alba, a white worm, etc.). 



The generic name may be used only once in the entire animal 

 kingdom, and duplication between the plant and animal kingdoms is 

 discouraged. To facilitate the discovery and elimination of duplication, 

 international lists of genera are maintained. When an instance of dupli- 

 cation is discovered, the earlier usage takes precedence. The author of 

 the second usage is allowed time to rename his genus, but if he fails to 

 do this, any other person may rename it. The same procedure applies 

 when two species within the same genus receive the same specific name. 



When a single species has been named more than once, again the 

 earlier publication takes precedence. The person discovering the error 

 establishes the first published name as the valid name, and places the 

 second name as a synonym having no validity. Synonyms are a nuisance, 

 since papers may have been published in which they were used as identi- 

 fication. They cannot be discarded, nor can they be used later to name 

 new species. 



These are just a few of the rules that govern the system of naming. 

 They are spelled out in 36 articles in the International Rules of Zoo- 

 logical Nomenclature, a document accepted in 1901 by the Fifth Inter- 

 national Zoological Congress. The system is administered by the Inter- 

 national Commission on Zoological Nomenclature, which arbitrates 

 disputes that arise and may offer interpretations or recommend modi- 

 fication of the rules to the congress. Adherence to the system is entirely 

 voluntary, but the need for clarity and uniformity is so obvious that no 



