62 MANUAL OF DETERMINATIVE BACTERIOLOGY 



RECOMMENDATIONS 



Article 5. In the future it is recommended that authors of generic names definitely 

 designate type species; and that in the selection of types of genera previously pub- 

 lished, but of which the type would not be indicated by the preceding rules, the fol- 

 lowing points be taken into consideration: 



(a) The type species should usually be the species or one of the species which the 

 author had chiefly in mind. This is often indicated by 



1. A closer agreement with the generic description. 



2. Certain species being figured (in the same work). 



3. The specific name, such as vulgaris, communis, medicinalis or officinalis. 



(b) The type species should usually be the one best known to the author. It may 

 be assumed that an indigenous species (from the standpoint of the author), or an eco- 

 nomic species, or one grown in a botanical garden and examined by the author, would 

 usually represent an author's idea of a genus. 



(c) In Linnaean genera the type should usually be chosen from those species in- 

 cluded in the first technical use of the genus in pre-Linnaean literature. 



(d) The types of genera adopted through citations of non-binomial literature 

 (with or without change of name) should usually be selected from those of the original 

 species which received names in the first binomial publication. 



(e) The preceding conditions having been met, preference should be shown for a 

 species which will retain the generic name in its most widely used sense, or for one 

 which belongs to a division of the genus containing a larger number of species, or, 

 especially in Linnaean genera, for the historically oldest species. 



(f) Among species equally eligible, the preference should be given to the first 

 known to have been designated as the type. 



(g) If it is impossible to select a type under the conditions mentioned above, the 

 first of equally eligible species should be chosen. 



While the rules and recommendations of the above botanical codes are ap- 

 plicable in general to bacteria and related microorganisms, the fact that 

 these are not infallible is evident because the rules developed independently 

 by zoologists (see Proc. Biol. Soc. Washington, 39, 1926, 75, for the latest 

 Code of Zoological Nomenclature) frequently follow a quite different course. 

 In some cases at least the zoological rules will appeal to microbiologists as 

 more likely to produce uniformity of usage than the botanical rules. 



For example, microbiologists assembled at the Second International 

 Microbiological Congress in London, 1936 accepted (Jour. Bact., S3, 1937, 

 445) Art. 13 of the International Rules of Zoological Nomenclature as 

 preferable to Rec. 43 of the Botanical Rules to govern bacteriological 

 practice. This reads as follows: "While specific substantive names derived 

 from names of persons may be written with a capital initial letter, all other 

 specific names are to be written with a small initial letter. Some examples 

 taken from bacteriological literature are: Salmonella Schottmuelleri or 

 Salmonella schottmuelleri. Bacillus Welchii or Bacillus welchii, Acetobacter 

 Pasteurianum or Acetobacter pasteurianum, Corynebacterium ovis, Nitro- 

 somonas javanensis, Rhizobium japonicum." 



