18%.] The FortnubUum 9/ the Natural Sciences. 109 



III. Nomenclature. 



Nomenclature is like pens, ink and paper; it is not science, 

 but it is essential to the pursuit of science. It is, of course, for 

 convenience that we use it but it does not follow from that 

 that every kind of use of it is convenient. It is a rather com- 

 mon form of apology for misuse of it to state that as it is a 

 matter of convenience, if makes no difference how many or 

 how few names we recognize or use. An illustration of this 

 bad method is the practice of subdividing a genus of many 

 species into many genera, simply because it has many species. 

 The author who does this ignores the fact that a genus has a 

 definite value, no matter whether it has one or five hundred 

 species. I do not mean to maintain that the genus or any 

 other value has an absolute fixity in all cases. They un- 

 doubtedly grade into each other at particular places in the 

 system, but these cases must be judged on their own merits. 

 In general there is no such gradation. 



Nomenclature is then orderly because the things named 

 have definite relations which it is the business of taxonomy, 

 and nomenclature its spokesman, to state. Here we have a 

 fixed basis of procedure. In order to reach entire fixity, a rule 

 which decides between rival names for the same thing is in 

 force. This is the natural and rational law of priority. With the 

 exception of some conservative botanists, all naturalists are, so 

 for as I am aware, in the habit of observing this rule. The 

 result of a failure to do so is self evident. There is, however, 

 some difference of opinion as to what constitutes priority. 

 Some of the aspects of the problem are simple, others more 

 difficult. Thus there is little or no difference of opinion as to 

 the rule that the name of a species is the first binomial which 

 it received. This is not a single date for all species, since 

 some early authors who used trinomials and polynomials 

 occasionally used binomials. A second rule which is found 

 in all the codes, is that a name in order to be a candidate for 

 adoption, must be accompanied by a descriptive diagnosis or 

 a plate. As divisions above species cannot be defined by a 

 plate, a description is essential in every such case. 



