410 THE BOTANICAL EXCHANGE CLUB OF THE BRITISH ISLES. 



The genus Geranium affords another example. Pelargonium and 

 Eronium, separated from it by L'Heritier in 1787, contain a larger 

 number of species than were left in Geranium. Again this proportion, 

 according to the Kew Index, is maintained. 



Other examples exist in shoals ; we may refer to Myagrum, 

 which had nine species, five belonging to Rapistrum, one each to 

 Myagrum, Vogelia, Cochlearia, and Camelina. Are all the species 

 of Rapistrum to become Myagrum % 



Finally, take the genus Carduus, consisting of twenty-six species. 

 Carduus Acarna Sp. PL, ed. i., is in the 2nd edition transferred to 

 Cnicus. Of the twenty-six species five only are unplumed thistles, 

 e.g., C. nutans, C. acanthoides and C. crispus (which most modern 

 authors unite), and C. pycnocephalus and C. defloratus (which are in 

 ed. i.), whereas there are fifteen species of plumed thistles (Cirsium). 

 The six other species belong to five different genera — Tyrimnus, 

 Mariana, Notobasis, Serratula, and two are Jurinea. Is it seriously 

 contended that Carduus L. is to supersede Cirsium, and that the 

 true Thistles are to be called by some other name 1 



To myself the rule as it stands is fairly clear. In the case of 

 Antirrhinum and others, Linnaeus in the Genera Plantarum gives the 

 various generic names which he has associated together. If these are 

 disassociated, the respective species must be grouped under one or 

 other of those names ; that is Linaria and Antirrhinum for their re- 

 spective species, even if the numerical proportion is larger in one 

 of the subordinate names. See also under Statice. 



May we not, therefore, in view of the enormous upheaval such a 

 course as that foreshadowed in Statice and Nymphaea would entail, 

 modify Article 45 by adding a sentence to it — " That the rule only 

 ajjplies to future divisions of genera or groups, and has no retrospective 

 action. As with the definition of species, so too with genera, the rule 

 of priority shall be enforced 1 ?" The adoption of such a rule appears 

 to be necessary, since, as it stands, at anyrate in the English version, 

 Article 45 is not free from ambiguity, and may, if unaltered, lead to 

 unnecessary disturbances in nomenclature. 



EXAMPLES IN WHICH THE NUMERICALLY INFERIOR PORTION OF A 

 GENUS RETAINS THE ORIGINAL NAME. 



Hyacinth us L. ? 13 species, 2 only of which are Hyacinthus, 



