136 College of Forestry 
has been built up and upon this, mats of reindeer lichen are 
established. See Fig. 22. Further up and on more level 
ground, a matrix of fine sand covers the bed rock. A thicker 
layer of duff covers the sand and this supports a shrub vege- 
tation chiefly of heath species and especially blueberry ( Vac- 
cinum angustifolium), but this way beneath a stand of 
red pine which has become established at this point. Farther 
back from the lake, the vegetation history has proceeded so 
far that the rock strewn area is quite generally hidden be- 
neath a deep cover of duff in drier places (under conifers) 
and of leaf mold in moister places (under hardwoods). Even 
large boulders rising above the general level are more or less 
covered with a soil matrix which supports at least polypody 
(See Fig. 23) and perhaps small shrubs and even young sap- 
lings (e. g. Betula lutea). Finally, the main area of the 
promontory, which, to begin with, was strewn with boulders 
and big angular rock fragments, is covered in general with a 
climax forest dominated by sugar maple, yellow birch, beech, 
hemlock, some paper birch and red spruce and a varied forest 
floor vegetation. 
Returning now to the problem of the bare rock surface: it 
is quite within probability that with such a steep slope and 
so full an exposure to sun and storm, the instense drying 
effect, the wash of rainfall and the sliding snow and iee, 
vegetation could never establish itself strongly enough to 
build up a supporting humus cover. But even this seemingly 
hopeless invasion may be carried through especially with help 
given by the established vegetation at the crest. But as to 
the general status of the boulders covering the promontory, 
for the greater number, the problem is solved by their being 
covered by the great mass of debris which accumulates over 
the area on which they lie. There are, however, some so 
large that they stand out free from the general substratum. 
A, rounded boulder more or less exposed to the sun had only 
this vegetation: (1). Closely adhering crusts of lichen; 
(2), patches of dark colored moss (Grimmia ovata?) (3) ; 
