462 Lichenes of New England. 
and several authors have treated the subject at large. 
I will enumerate a few of our New England species, 
which in other countries have been found valuable 
for the purposes of dying. Nearly all the common - 
Parmelie ; Squamaria Candelaria; Cetraria Islandica 
and C. juniperina $. pinastri ; several Lecanore, and 
especially L. tartarea, which is the “cud bear” of 
commerce, and of which ‘whole cargoes” are im- 
ported into Britain, and L. Parella, the “ perelle ” of 
commerce, and also an article of trade in Europe; 
several Gyrophore; Usnea plicata, and others of the 
filamentous lichens, may be mentioned.  Evernia 
vulpina is not only employed as a dye-stuff, but it is, 
according to Pontoppidan, (and a similar account: is 
given in L. Fl. Suec.) very poisonous, and used in 
Sweden and Norway to kill wolves; which would 
lead us to suspect some active principle in this lichen 
worth examining; though I have not found its sen- 
sible properties very perceptible to the taste. A 
slight sensation of burning in the mouth continued, 
however; for some time after I made the experiment, 
which, I supposed, was caused by the lichen. © This 
mode of experimenting on the properties of these 
plants, will be found easy and interesting. The fla- 
vor of nearly allied species of the same genus will 
be found very different, while the same lichens agree 
nearly in taste with species of other genera differing 
from them in almost every other respect. A E 
remark is quoted from “ Weiss Pl. Crypt. Fl. Gott." 
in Humboldt's “FÌ. Friberg,” p. 25, to the effect that 
the virtues of lichens vary with the trees on whie 
they grow: — * Lichenum enim eædem species, si 
