406 THE BOTANICAL EXCHANGE CLUB OF THE BRITISH ISLES. 



It may be well to state that in my correspondence with Alphonse 

 de Candolle in 1891, I gave the reason which had induced me to 

 formulate a rule {Pharmaceutical Journal 1892) that both generic and 

 specific citation should date from the Species Plantarum of 1753, the 

 names of genera at that time dating from 1737. This allowed a large 

 number of competing names to intervene between the earlier and the 

 later works of Linnaeus, so that Kuntze (Rev. Gen. PI.) made an 

 enormous number of plant changes by using genera which had been 

 described between the dates alluded to. After some considerable ex- 

 change of views, the veteran botanist wrote to me in 1892, saying he 

 should no longer oppose, but in future would support the date 1753 as 

 the starting point of both genera and species. Quite independently 

 the great botanist Ascherson also entered into communication with De 

 Candolle on the same subject, and chiefly by his efforts, the matter 

 was put before the botanical world, and was eventually adopted at the 

 Vienna Congress. It is, however, greatly to be regretted that, in order 

 to avoid temporary inconvenience, the principle of priority should have 

 been sacrificed by the vote taken at that meeting, when an arbitrary 

 "List of Nomina Conservanda " was issued on most illogical and un- 

 just lines, the very unfairness of which will probably prevent them 

 having a more than temporary place in the Rules of Nomenclature. 

 The permanence of the trivial, in whatever grade it is placed, should 

 also have been insisted on, and it would have been on the whole ad- 

 vantageous had there been no exception to the permanence of the 

 oldest trivial, even if the name had been subsequently used for another 

 plant in the genus. In such cases, and they are not sufficiently numer- 

 ous to warrant the infringement of a great principle, the more recent 

 combination would have to be renamed. 



Article 45. " When a genus is divided into two or more genera, 

 the name must be kept and given to one of the principal divisions. If 

 the genus contains a section or some other division, which, judging by 

 its name or its species, is the type or the origin of the group, the name 

 is reserved for that part of it. If there is no such section or sub- 

 division, but one of the parts detached contains a great many more 

 species than the others, the name is reserved for that part of it." This 

 rule has been recently construed by the eminent botanist M. Briquet 

 into using Nymphaea vice Castalia, and the consequent restoration 

 of Smith's JVuphar, which is so much later than Salisbury's Castalia ; 

 although in this instance the Linnean genus Nymphaea consists of 



