50 MANUAL OF DETERMINATIVE BACTERIOLOGY 



INTERNATIONAL RULES OF BOTANICAL 

 NOMENCLATURE, 1930-1935 



Chapter I. General Considerations and Guiding Principles (Art. 1-9) 



Art. 1. Botany cannot make satisfactory progress without a precise system of 

 nomenclature, which is used by the great majority of botanists in all countries. 



Art. 2. The precepts on which this precise system of botanical nomenclature is 

 based are divided into principles, rules, and recommendations . The principles (Art. 

 1-9, 10-14, 15-19) form the basis of the rules and recommendations. The object of the 

 rules (Art. 19-74) is to put the nomenclature of the past into order and to provide for 

 that of the future. They are always retroactive; names or forms of nomenclature 

 contrary to a rule (illegitimate names or forms) cannot be maintained. The recom- 

 mendations deal with subsidiary points, their object being to bring about greater 

 uniformity and clearness in future nomenclature : names or forms contrary to a recom- 

 mendation cannot on that account be rejected, but they are not examples to be 

 followed. 



Art. 3. The rules of nomenclature should be simple and founded on considerations 

 sufficiently clear and forcible for everyone to comprehend and be disposed to accept. 



Art. 4. The essential points in nomenclature are: (1) to aim at fixity of names; 

 (2) to avoid or to reject the use of forms and names which may cause error or ambigu- 

 ity or throw science into confusion. 



Next in importance is the avoidance of all useless creation of names. 



Other considerations, such as absolute grammatical correctness, regularity or 

 euphony of names, more or less prevailing custom, regard for persons, etc., notwith- 

 standing their undeniable importance, are relatively accessory. 



Art. 5. In the absence of a relevant rule, or where the consequences of rules are 

 doubtful, established custom must be followed. 



Art. 7. Scientific names of all groups are usually taken from Latin or Greek. 

 When taken from any language other than Latin, or formed in an arbitrary manner, 

 they are treated as if they were Latin. Latin terminations should be used so far as 

 possible for new names. 



Art. 8. Nomenclature deals with: (1) the terms which denote the rank of tax- 

 onomic groups (Art. 10-14) ; (2) the names which are applied to the individual groups 

 (Art. 15-72). 



Art. 9. The rules and recommendations of botanical nomenclature apply to all 

 groups of the plant kingdom, recent and fossil, with certain distinctly specified ex- 

 ceptions. 



Chapter II. Categories of Taxonomic Groups, and the Terms 

 Denoting Them {Art. 10-14, Rec. I, II) 



Art. 10. Every individual plant belongs to a species (species), every species to a 

 genus {genus), every genus to a family (Jamilia), every family to an order (orda) 

 every order to a class (classis), every class to a division (diviso). 



Chapter III. N^ames of Taxonomic Groups (Art. 15-72, Rec. III-L) 

 Section 1. General Principles: Priority {Art. 15-17, Rec. Ill) 



Art. 15. The purpose of giving a name to a taxonomic group is not to indicate the 

 characters or the history of the group, but to supply a means of referring to it. 



Art. 16. Each group with a given circumscription, position, and rank can bear 

 only one valid name, the earliest that is in accordance with the Rules of No- 

 menclature. 



