Vl] THE RULE OF PRIORITY. 113 



One of the most important and frequently disputed questions 

 associated with the naming of species is that of priority. No 

 name given to a plant in pre-Linnaean days need be considered, 

 as our present system of nomenclature dates from the institution 

 of the binominal system by Linnaeus. As a general rule, which 

 it is advisable to follow, the specific name which was first given 

 to a plant, if accompanied by a figure or diagnosis, should take 

 priority over a name of later date. If A in 1850 describes a 

 species under a certain name, and in 1860 B proposes a new 

 name for the same species, either in ignorance of the older 

 name or from disapproval of A's choice of a specific term, the 

 later name should not be allowed to supersede ^'s original 

 designation. Such a rule is not only just to the original 

 author, but is one which, if generally observed, would lead to 

 less confusion and would diminish unnecessary multiplication of 

 specific names. Some writers would have us conform in all 

 cases to this rule of priority, which they consistently adhere 

 to apart from all considerations of convenience or long-esta- 

 blished custom. There are, however, cogent reasons for main- 

 taining a certain amount of freedom. While accepting priority 

 as a good rule in most cases, it is unwise to allow ourselves to be 

 too servile in our conformity to a principle which was framed in 

 the interests of convenience, if the strict application of the rule 

 clearly makes for confusion and inconvenience. A name may 

 have been in use for say eighty years, and has become perfectly 

 familiar as the recognised designation of a particular fossil ; it is 

 discovered, however, that an older name was proposed for the 

 same species ninety years ago, and therefore according to the 

 priority rule, we must accustom ourselves to a new name in 

 place of one which is thoroughly established by long usage. 

 From a scientific point of view, the ideal of nomenclature is to 

 be plain and intelligible. To prefer priority to established usage 

 entails obscurity and confusion. If priority is to be the rule 

 which we must invariably obey in the shadowy hope that by 

 such means finality in nomenclature^ may be reached, it becomes 

 necessary for the student to devote no inconsiderable portion 



1 Knowlton (96) p. 82. 



