Lichenes of New England. 463 
. diversis arboribus innascuntur, diversum habitum 
VIRES que sibi assumunt." And another writer has 
stated that where,the same lichens are found growing 
on rocks as well as trees, the plants from the former 
are “evidently more productive ” of color, than those 
from the latter. More observations of this kind 
would be very valuable. And perhaps the remark 
may be allowed, that chemical analysis might be ap- 
plied more extensively than it has yet been, to settle 
the real character of these groups and species, which 
appear to be reputed as remarkably different in their 
properties, as they are like in habit. By this means, 
it is probable, some general results would be obtained 
and a more complete view of the subject. Sticta 
pulmonacea, or Oak-lungs, is one of the ancient sim- 
ples which were employed forthe cure of pulmona- 
ry complaints. 'The doctrine of signatures, which 
found some resemblance in the reticulated thallus of 
this plant to the figure of the lungs, aided probably 
in giving the lichen the distinction it acquired ; but 
later experimenters have detected in it “a portion, 
equal to one eighth of its substance, of a reddish 
gum, having a slightly bitter taste," which, perhaps, 
may also in part account for its reputation. Variola- 
ria faginea is now extensively used in France, says 
Hooker, in the manufacture of oxalic acid. It is 
further remarked by the same author, that this prin- 
ciple has been found to be common to several other 
crustaceous lichens; and Braconnot considered the 
oxalate of lime as bearing “the same relation to the 
Cryptogamia, as carbonate of lime to corals, and 
