122 GENERAL SYSTEMATIC BACTERIOLOGY 



Subsection 3. Names of genera and divisions of genera 



Article 24. Genera receive names, substantives (or adjectives used as sub- 

 stantives) in the singular number and written with a capital letter, which maybe 

 compared with our own family names. These names may be taken from any 

 source whatever and may even be composed in an absolutely arbitrary manner. 



Examples: Rosa, Convolvulus, Hedysarum, Bartramia, Liquidambar, Gloriosa, 

 Impatiens, Manihot. 



Comments. Examples of bacterial genera are Bacillus, Actinom.yces 

 and Vibrio. 



Not infrequently, particularly in medical writers, one finds a decided 

 tendency to ignore the rule that a genus name must, when used as such, 

 always be written with a capital letter. Many of our medical journals 

 and even some which publish scientific articles on medical bacteriology' 

 write bacillus typhosus or bacillus tuberculosis. It is true that sometimes 

 a word with the same spelling as a generic name may be used as a 

 morphologic designation. It cannot be considered incorrect to speak 

 of tubercle bacillus, for this is a common name or vernacular designation. 

 As Stiles (1905, p. 16) says: (this same rule holds in zoological 

 nomenclature) 



This custom of capitalizing the generic name has come down to us from former 

 centuries, and while it now has its practical basis, its historic basis is probably due 

 to the custom earlier authors had of capitalizing all Latin substantives when used 

 in nomenclature. At present the custom is so thoroughly established that bota- 

 nists and zoologists experience much the same sensation in seeing "bacillus 

 tuberculosis" or "plasmodium malariae," instead of Bacillus tuberculosis and 

 Plasmodium malariae. that they would if they found a reference to "american" 

 authors or to "doctor s. weir mitchell." 



It is also considered good form to write names of genera, particularly 

 when associated with a specific name, in italics. Some of our medical 

 journals have recentlj^ abandoned this practice under the plea that 

 it is an unnecessary expense and that italics should be used only for 

 the sake of emphasis. This is unfortunate as it has in the past served 

 as a satisfactory method to indicate clearly in a text just when names 

 were being used in a strict scientific sense. 



Some purists have taken exception to the statement that these names 

 may be taken from any source whatever and may even be composed in 

 an absolutely arbitrary manner. Clements (1902) in his paper on Greek 

 and Latin in biological nomenclature states that vernacular names 

 should be invalid, and that a name or term should be regarded as invalid 

 unless constructed according to the principles of word formation in 



