THE CLASSIFICATION OF PLANTS 2133 



the Papilionaceae as constituting an independent family may use that name, 

 although it is not formed in the prescribed manner. 



Article 24. Names of sub-Families are taken from the name of one of 

 the genera in the group, with the ending -oideae. Similarly for tribes with 

 the ending -eae and for sub-tribes with the ending -inae. 



Article 27. Names of species are binary combinations, consisting of the 

 name of the Genus followed by a single specific epithet. The specific 

 epithet when adjectival in form and not used as a substantive agrees in 

 gender with the generic name. 



Article 38. From ist January 1935 names of new groups of recent 

 plants, the Bacteria excepted, are considered as validly published only 

 when they are accompanied by a Latin diagnosis. 



Article 46. For the indication of the name of a group to be accurate 

 and complete and in order that the date may be readily verified it is necessary 

 to cite the author who first published the name in question. 



Article 49. When a genus or a group of lower rank is altered in rank 

 but retains its name or epithet, the original author must be cited in parenthe- 

 sis, followed by the name of the author who eflFected the alteration. The 

 same holds when a subdivision of a genus, a species or a group of lower 

 rank is transferred to another genus or species with or without alteration 

 of rank. 



Article 61. A name of a taxonomic group is illegitimate and must be 

 rejected if it is a later homonym, that is if it duplicates a name previously 

 and validly published for a group of the same rank based on a different 

 type. 



Article 69. In cases foreseen (under the Rules) the name or epithet to 

 be rejected is replaced by the oldest legitimate name. If none exists a new 

 name or epithet must be chosen. 



Article 74. These Rules can be modified only by competent persons 

 at an International Botanical Congress convened for the express purpose. 



The Third International Congress was held in Brussels in 1910 and 

 confirmed the rules proposed by the Vienna Congress. The Fourth Inter- 

 national Congress, which should have been held in 19 15, was postponed 

 owing to the First World War and was held in Ithaca, U.S.A., in 1926. At 

 this congress no changes in the Rules of Nomenclature were made and it 

 was left to the Fifth International Congress held at Cambridge in 1930 to 

 make further changes. 



The Sixth International Congress was held in Amsterdam in 1935 and 

 the Seventh Congress, which should have been held in 1940, was postponed 

 until 1950 in Stockholm, owing to the Second World War. 



THE ALGAE 



The history of the systematic arrangement of the Algae starts from Lm- 

 naeus in 1753, but it is only within the last hundred years that sufficient has 



