LICHENOLOGY OF ICELAND 109 
on the unity where others see diversity of species, show a com- 
prehension of the relationship of the lichens which, I believe, will 
prove to contain many truths when once, at some future time, we 
succeed, by experiments, in clearing up the limitation of the 
species. But it should be borne in mind that, for the time being, 
his systematic considerations (which are excellent according to my 
opinion) are theories, pure and simple, which experiment alone 
can set upon a firm foundation, and Deichmann Branth him- 
self must have had a clear understanding of this. It is only to be 
hoped that, one day, the necessary culture-experiments will be made, 
which will eventually do that justice to his considerations, which 
up to the present, has been too scanty. 
To the other group of investigators belong virtually all the 
lichenologists of the present day — all those who so often establish 
species upon quite slight peculiarities of structure in the individuals 
considered. 
The inconveniences this causes with regard to the synonymy 
of the lichens, is evident. The same name is sometimes used in a 
limited and sometimes in a very wide sense. The same species is 
sometimes referred to one, and sometimes to another genus. This 
creates a confusion, which in several cases, is simply impossible 
to reduce to order. 
In order to clear away the difficulties with regard to synonyms, 
it has been the custom from the earliest times, to preserve in mu- 
seums “original specimens,” i. e. the specimens on which the author 
has founded his species. This custom is very commendable, but 
by no means so satisfactory, as we are frequently inclined to be- 
lieve; the fact being that lichens alter rather essentially in the course 
of time, frequently change colour, and alter their chemical reactions, 
etc., to say nothing of the fact that the specimen may not be cut 
up to ascertain the anatomical resemblance between it and other 
specimens, the identity of which is wished to be ascertained; and 
without such anatomical investigation, comparison is simply worth- 
less in all difficult cases. This fact should be emphasized in order 
to remove, once for all, the entire foundation built up under the 
persistent worship of “original specimens.” We must demand that 
the author of the species should describe his species well, and not 
only leave some gnawed or doubtful original specimen, which is 
respected.so highly that no one dares to dissect it, and thereby 
deprive it of its importance, while often the very specimen proves, 
