1905] OLSSON-SEFFER—PH YTOGEOGRAPHIC NOMENCLATURE 181 
shall a writer consider himself bound to follow these rules? They 
will certainly have to be changed from time to time. It is especially 
impossible to decide upon the fixity of special terms, because a name 
may be founded on ideas, which, in the course of time, owing to the 
progress of science, will be shown to be incorrect. No such rules 
as are applicable to the nomenclature of taxonomy can be brought 
into effect in regard to a system of terminology. 
The law of priority, which is the first principle in the nomen- 
clature of systematic biology, cannot be strictly adhered to in this 
connection. It has been proposed by CLEMENTS? that “priority of 
term and of application is to be regarded as the fundamental principle 
of phytogeographical nomenclature.” ENGLER, who must be con- 
sidered as better qualified than most men to judge in such a matter, 
in a footnote to CLEMENTS’ article expresses strong objection to the 
introduction of a law of priority in phytogeography. The acceptance 
of such a law would lead to the retaining of names which are neither 
expressive of the idea they represent nor suitable in other ways. If 
an absolute rule of priority is maintained, how are we to arrange for 
the retaining of names that originally expressed ideas now considered 
as false? Every terminology shows traces of such names. What 
conception in that case shall represent the type of the systematist 
and bear the old name? It can be seen at a glance that the 
tule of priority is not practicable here as it may be in taxonomic 
nomenclature. 
The question whether to retain an old term which is not good, 
or to abolish it and substitute a new name, will always be difficult. 
If a free hand is given, phytogeography will have a heavy load of 
useless synonyms that always will act as a drag on true science, and 
create much more confusion than exists now. If on the other hand 
any restriction can be brought about, it must be to the effect that 
Priority should be conceded to such a name only as has been properly 
defined in a work accessible to scientists. To impose new names 
needlessly upon previously named conceptions will always be con- 
sidered bad form, and a general consensus of opinion prevails as to 
this habit. Suddenly introducing a large number of new terms into 
* CLEMENTS, F, E., A system of nomenclature for phytogeography. Beiblatt 
Bot. Jahrb. 70: — 20. 1g02. 
