THE CLASSIFICATION OF PLANTS 213 1 



would discard it altogether. This would be all the more advisable if the 

 tendency to divorce the Fungi from the rest of the Plant Kingdom were to 

 become more widely accepted. It may be desirable therefore to raise the 

 Algae, the Fungi, possibly with the Lichens associated with them, and the 

 Bacteria, each to Phylum rank, equal with the Bryophyta or Pteridophyta. 

 The new names would therefore be: the Phycophyta, the Mycophyta and 

 the Bacteriophyta. 



Within these more primitive groups we may expect to find divergences 

 of opinion most strongly expressed, and the methods of classification most 

 variable. In fact, the more critically and extensively a group of organisms 

 is studied, the more various become the methods of classification. The 

 Lichens, which have been studied by comparatively few workers, still 

 retain the same outline classification which was proposed over fifty years 

 ago. On the other hand, because of the activity and number of mycologists, 

 the Fungi have never settled down to any fixed system of classification. 

 Similarly the Bryophyta have a relatively definite system, but the systematic 

 arrangement of the Angiospermae is in a constant state of flux. 



LAWS OF BOTANICAL NOMENCLATURE 



If the names of plants are to have international value it is necessary 

 that some body of rules should be adopted to govern nomenclature. More- 

 over, since it is quite possible for the same plant to be described and named 

 by two independent investigators working independently at difi^erent times 

 or in difi^erent parts of the world, some principle must be adopted to decide 

 which name shall be accepted and which rejected. Again there must be a 

 starting-point in respect of the names to be considered in the case of plants 

 which have been known since ancient times. Bearing in mind that in pre- 

 Linnean times botanical plant names were more like brief Latin descrip- 

 tions than the binomial Latin names we are familiar with today, it is easily 

 realized that the correct application of old names is often uncertain. 



The first attempt to draw up a code of rules was made at the Inter- 

 national Congress of Botanists held in Paris in 1867. The application of 

 these rules evoked criticisms and a revision was undertaken at a further 

 congress in Vienna in 1905, which was devoted mainly to this topic. The 

 Rules of Nomenclature formulated at this congress have formed the basis 

 of all subsequent discussions, and, though they have been amended and 

 extended in later congresses, the greater part of the Vienna rules still apply. 



The rules themselves are fairly simple in form and are considered 

 binding upon all botanists. They are accompanied by a series of more 

 extensive recommendations, which have not the force of rules and the 

 observance of which is optional. The following excerpts from selected 

 articles of the latest published code, that of 1950, include the rules of most 

 general application. 



Article 10. Every individual plant, interspecific hybrids and chimaeras 

 excepted, belongs to a Species, every Species to a Genus, every Genus to a 



