INTRODUCTION. 11 



given genus in different portions of its range is indicated and 

 the general generic range is briefly given. This compilation 

 permits the student to see at once in which portion of its gen- 

 eral range any given genus is preponderantly developed, and 

 to compare the relative development of allied or distant groups. 

 Citation of authors of genera and species. In order to ob- 

 tain stability of nomenclature it is necessary to provide that the 

 name of a plant, the specific name, can not be changed through 

 caprice or whim. Nor can it be changed through ignorance, 

 providing the mistake through which the change was made has 

 been discovered. The refusal to correct mistakes and the dis- 

 inclination to do thorough bibliographical work before publish- 

 ing a new specific name is the cause of most confusion in botan- 

 ical nomenclature. Hence has arisen the so-called international 

 law or law of priority which provides that the earliest pub- 

 lished specific name of any plant must stand providing that 

 name is not antedated by some other similar name applied to a 

 plant belonging in the same genus. Many botanists do not 

 admit the validity of this principle except in the case of species 

 which they may have themselves named and published. With 

 reference to others they are accustomed to insist that ' ' cus- 

 tom," "long-established-habit" and a conservative condition 

 must be maintained. This is to save the difficulty of having to 

 revise their own systems of nomenclature, and serves in many 

 cases to cover inaccuracies or hastiness. With this conservative 

 position, the unthinking and unbotanical are always distinctly 

 satisfied and are accustomed to declare that botanical nomen- 

 clature is purely a "practical matter " and should be taken out 

 of the hands of the botanists altogether and turned over to 

 some unprofessional commission for settlement (5). Objec- 

 tions of this sort are natural, for the changing of names in 

 our accustomed department of science is always a confusing 

 matter. Such criticism is, however, unthinking and unbotan- 

 ical because it fails to recognise that the whole difficulty has 

 originated on account of just such conditions as are extolled 

 and recommended for perpetuation. The only way to obtain a 

 stable nomenclature is by rigidly enforcing the law of priority 

 with reference to specific names. All instability finds its well 

 spring in the disregard of this law, and stability under our 

 present general system of nomenclature can only be obtained 

 by strict adherence to the oldest available specific name, by 

 whomever or wherever it may have been published. 



(5) Rand: Bot. Gazette, XVI. 318-319 (1891). 



