HOW BACTERIA ARE NAMED AND IDENTIFIED 



Prof. R. E. Buchanan 



Dean of Graduate School {Emeritus) atid Director of Experiment Station (Emeritus), 

 Iowa State College, Ames, Iowa 



A manual of determinative bacteriology, such as the present volume, has 

 several important functions. These should be recognized and understood by the 

 student if he is to use the volume with satisfaction. 



First, the manual should list and describe all the kinds (species) of bacteria 

 and viruses known through adequate publication in bacteriology or virology. 

 Obviously, however, only those organisms that have usable published descrip- 

 tions can be included. 



Second, the manual should arrange the descriptions of the kinds (species) in 

 smaller or larger groups (taxa, singular, taxon) on the basis of resemblances and 

 differences in an effort to show inter-relationships. 



Third, the manual should indicate for each species its correct name, likewise 

 the correct name for each group (taxon) of related species. 



That branch of biology which has for its purpose the orderly arrangement of 

 the descriptions of species and other taxa, together with the application of the 

 correct names, is termed taxonomy. 



The manual, through its indices, should enable the student who knows the 

 correct name of an organism (or even a synonym of such name) to discover the 

 description of the organism and its characteristics, as well as something of its 

 relationships. If, on the other hand, he has an organism whose characteristics 

 and description he has determined or recorded, but whose name and relation- 

 ships he does not know, a satisfactory manual, through its keys, should enable 

 him to determine the correct name, its probable relationships and its position in 

 a classification. 



Nomenclature. The necessity for applying names to species or kinds of bacteria 

 and to groups of inter-related organisms is self-evident. A name given by one 

 person should be understood by others, and as far as practicable all individuals 

 should use the same name for the same kind of organism. It is helpful, therefore, 

 if there can be agreement regarding the method of naming bacteria and agree- 

 ment as to the correct name for each kind or species. Nomenclature includes all 

 discussions as to methods of naming and of the correctness of particular names. 



What kinds of names are used. Two kinds of names are commonly given 

 to the different species of plants and animals, (1) the common, provincial, ver- 

 nacular or casual names and (2), the international or scientific names. These 

 should be carefully differentiated, and their respective advantages and disad- 

 vantages noted. 



It is inevitable, and on the whole probably desirable, that for each kind of 



15 



