Bacteria and Viruses 27 



Rule 5. Sect. 1. Naming of Taxa 



For a subsection and a lower subdivision of a genus the epithet is 

 preferably a plural adjective agreeing in gender with the generic 

 name and written with a capital initial letter. 



The treatments of subdivisions of a genus are distinctly different 

 in Botany and in Bacteriology. These differences may be summarized: 



1. Bacteriology recognizes the subgenus as the only subdivision 

 between genus and species. Botany recognizes several, in- 

 cluding subgenus, section, subsection, series and subseries. 



2. Bacteriology and Zoology regard a subgeneric name as subject 

 to the same rules and recommendations as a generic name. 

 Botany has a series of special rvdes: the subgenus and genus 

 are 7iot co-ordinate nomenclaturally. 



3. Bacteriology agrees with Zoology in regarding names of all 

 subgenera, genera and higher groups as uninomial. Botany 

 regards the name of a subgenus as an epithet related to or 

 modifying the generic name. 



4. Bacteriology and Zoology definitely regard the subgenus as a 

 taxon. Whether the subgenus in Botany is a taxon is problem- 

 atical. It is difficiUt to equate epithet and taxon. 



5. Bacteriological and zoological rules forbid the use of the same 

 subgeneric name in different genera. The name of a subgenus 

 may be the same as that of the genus in which it is included, 

 but may not be a homonym of the name of another genus. In 

 Botany the subgeneric epithet in a genus may duplicate the 

 name of another genus or of an epithet of a subgenus in 

 another genus. 



Names of Genera. Although Rule 5 states that almost any combi- 

 nation of letters may be proposed and used as a generic name; authors 

 should hold in mind the directive of Principle 4 which states that 

 names of taxa are usually taken from Latin or Greek, but if taken 

 from any other language or formed in an arbitrary manner they are 

 to be treated as Latin, and Latin terminations should be used so far 

 as possible. In other words, while any combination of letters may 

 be used, certain methods of coining generic names are much to be 

 preferred. One may well observe the Linnaean injunction that the 

 most appropriate and satisfactory generic name is one derived from 

 the Greek, usually the result of joining appropriate Greek stems to 

 form a new word. 

 Examples of generic names, 



With a single Greek stem: Bacterium, Clostridium, Proteus, 

 Plectridiiim. 



Compounds with two Greek stems: Actinomyces, Aerobacter, 

 Chondromyces, Corynebacterium, Streptococcus, Haemophilus, Tre- 

 ponema, Thiothrix, Pseudomonas. 



With a single Latin stem: Vibrio, Spirillum, Sarcina, Bacillus, 

 Cloaca. 



