Classification 43 



The starting point of taxonomy is considered to be the tenth edition 

 (1758) of Linnaeus's Systema Naturae. Names previous to that date 

 are invahd. Since the time of Linnaeus, many new species of animals 

 have been described, and their naming is determined by a set of rules 

 known as the International Rules of Zoological Nomenclature. 



In describing a new animal, the taxonomist chooses one indi- 

 vidual which he designates as the type. This particular specimen is 

 then considered to be the standard for this species. The first name 

 given to a species is the valid name, providing that the describer has 

 complied with various rules of nomenclature. This is known as the 

 law of priority. 



What Is a Species? — The whole system of classification is based 

 upon the fact that definite kinds or species of animals do exist, that is, 

 any one kind of animal has a set of characteristics which set it apart 

 from all other animals. In general, a species is considered to be any 

 assemblage of animals which are in agreement so far as most details 

 of their anatomy are concerned and which interbreed. A species has 

 a constant recognizable form which clearly differentiates it from other 

 species. Species which resemble one another quite closely are grouped 

 as genera. 



Advantages of Scientific Names.— Scientific names are of ex- 

 treme importance in scientific research. Unless exact names are used, 

 no other worker can be sure of the test animal involved in an experi- 

 ment. Although there are common names for many of the larger ani- 

 mals, innumerable small forms of economic and biological importance 



have no such names. 



Common names, furthermore, are very carelessly used. The same 

 name as used in different sections of a country may refer to an en- 

 tirely different animal. Through much of the United States the scor- 

 pion is an animal with a sting in its tail, but through the southern parts 

 of this countrv, this same name refers to a lizard. Similarly, a gopher 

 through the Middle West refers to a small rodent ; m the Southeast it 

 refers to a burrowing turtle. A scientific name can never result m such 

 confusion for it refers to but a single species. 



Classifying Animals.-The scientific name of an animal is of 

 utmost importance in showing its immediate relationships. But no 

 onlv does any one kind of animal belong to a genus -^ ^P--';^ 

 belongs to other large groups. In fact, the entire classification of any 

 one animal shows it relationships to all other animals. 



