Bacteria and Viruses 17 



Principle 11. 



PRINCIPLE 11. The application of the names of taxonomic groups (taxa) is 

 determined by means of nomenclatural types. A nomenclatural type is that 

 constituent element of a taxon to which the name of the taxon is perma- 

 nently attached. 



NOTE. The nomenclatural type is not necessarily the most typical or repre- 

 sentative element of a taxon. It is merely that element with which the name 

 of a taxon is permanently associated. 



ANNOTATIONS 



Principle 11. The meaning and significance of this principle defining 

 the phrase nomenclatural type are developed by Rule 9 (j). 53) . 

 For example, the species Bacillus subtilis has been designated as the 

 nomenclatural type of the genus Bacillus. Whenever a genus Bacillus 

 is recognized by an author, he must include within it the species 

 Bacillus subtilis. One might even define the genus Bacillus as con- 

 sisting of the type species, Bacillus subtilis, together with such other 

 species as are placed with it because presumably sufficiently closely 

 related (congeneric) . 



The corresponding statement in the Botanical Code of 1952 (Article 

 18) is essentially the same, with the exception of the second sentence, 

 which reads: 



A nomenclatural type (typus) is the constituent element of a taxon 



to which the name of the taxon is permanently attached, whether 



as an accepted name or as a synonym. 

 The type concept is outlined in Articles 18, 19, 21 and 22. 



The Zoological Code outlines the type concept in much greater 

 detail than does either the Bacteriological or Botanical Code. 



