Palmer — Flora of the Grand Falls Chert Barrens. 101 
like masses thus detached lie isolated at the foot of the 
cliff or well out in the stream itself, bearing mute testi- 
mony to the slow ravages of time. The general and ex- 
tensive fracturing of the beds, due to the brittle nature 
of the rock, has doubtless been caused by stress and dis- 
placement, resulting either from a general upward move- 
ment of the region or a local settling in consequence of 
solution of the underlying limestone. Both causes have 
been operative at times more or less remote, and the lat- 
ter at least is still going on to some extent. 
Where a fissure has determined the line of cleavage the 
face of the cliff is often smooth and bare, not even a lichen 
finding foothold on its barren surface. However, owing 
to the peculiar gnarled and brecciated nature of the rock, 
the cliff faces are usually very irregular, affording many 
hollows, crevices and shelves, where soil borne by the 
wind or transported by rainwater from the hills above 
or by the alluvium laden waters of the stream in times 
of flood, finds ready lodgment. Here soon a few hardy 
mosses, grasses and other herbaceous plants establish 
themselves, adding vegetable mold to the deposit from 
year to year, and thus affording sustenance to other immi- 
grants, until in time the face of the cliff is adorned with 
a diversified flora wherever a little shade and moisture 
exist. 
In such situations are found several ferns, some of 
them not known elsewhere in the region. These are Dry- 
opteris marginalis, Asplenium Trichomanes and Cheil- 
anthes lanosa, although the last also extends up into the 
barrens and flourishes wherever a ledge or irregularity 
of surface affords a little protection. Asplenium par- 
vulum, Woodsia obtusa and several other ferns also 
abound, and Melica nitens and Arabis laevigata are quite 
characteristic, with many other plants common to the 
barrens and surrounding woods. 
Where the horizontal surface of the chert is smooth 
and level a condition of absolute barrenness prevails. This 
is however the case only over very small spots, as in gen- 
