different works as a basis of nomenclature.’? This is most cer- 
tainly true; yet I doubt if he would advocate a later work if it can 
be proved that Linnzeus 1s all sufficient as a basis for lichenologist 
—in fact, it seems to me that, in general, the more groups that can 
start from the same point the better, and if, logically, the lichens 
can start from Species Plantarum of 1753, it will make one less 
author to include among the basic works. Let us see now what 
advantages would be gained by adopting Acharius’ Lichenographia 
Universalis of 1810, as suggested by Dr. Farlow. It will be seen 
by again referring to the following list, that, of the eighty Lin- 
nean species, Acharius accepted all but six, thus agreeing almost 
entirely with the famous Swedish naturalist, and showing that 
adoption of the Acharian work would, for the species concerned, 
have little or no advantage. For the genera it would, of course, 
mean much more. In accepting Linneeus we do not lose, however, 
the Acharian genera, but reach them in due time, 
If lichenologists should accept the Acharian work as a basis 
of nomenclature, it would throw out, not only the two earlier works 
of Acharius, but also the important treatises of Hoffmann, Vaillant, 
De Candolle, Dickson, Ehrhart, Hudson, Schreber, Scopoli, Swartz, 
Persoon, Wahlenberg, Wulfen and others, not to mention those of 
Sebrader, Weber, Lightfoot, Link, Bellardi, Clemente, Desfon- 
taines, Sowerby, Gouan, Usteri, Harriman, Schleicher, Schrank, 
Vahl, Rebent, Pollich, Necker, Thunberg, Withering, Weis, 
Weigel, Westring and many more. It would also cause a great 
change in the present cited authorities, and affect such splendid 
recent works as Wainio’s Monographia Cladoniarum. 
Lastly, the discovery of the compound microscope has no 
doubt opened up an enormous field of study, and made possible the 
recognition of hundreds of lichen species unknown to Linneus, 
yet I cannot see why this should in the least affect the case. To 
some the chemical test of species has opened a large tield; but it 
still remains true that we must derive our nomenclature by priority 
from the first diagnostic describer or figurer who used the binomial 
system intelligently. That Linneeus described a large number of 
our cosmopolitan lichens successfully cannot be denied, and in 
this event, why should we search for later authority? By the 
adoption of any later work than Species Plantarum, I see in the 
case of lichens, little to be gained,and much that is eminently 
satisfactory to be disturbed. 
