1913) COOPER—ISLE ROYALE 207 
farthest advance the mass had taken the form of a tongue 4m. 
wide, extending 10 m. from the true bog margin. The slope of its 
surface was about 25° and the highest point reached was 4.5 m. 
above the bog level. The sphagnum supported a luxuriant growth 
of Ledum which completely covered it. The unusual abundance of 
flowers in comparison with the 
plants of the bog itself was a 
noteworthy feature, as was also 
the comparatively small size of 
the leaves, both facts perhaps 
indicating somewhat hard con- 
ditions. Vaccinium Oxycoccos 
and Chiogenes hispidula were 
also abundant, and frequent 
small seedlings of birch, black 
spruce, and balsam were found. 
©.6-1 m., and the edges were 
abrupt, but unfortunately the 
fire which destroyed the upland 
forest had encroached somewhat 
upon the bog vegetation, so that 
the marginal conditions could 
not be ascertained. 
4. The bog forest and its 
development 
Although in the Raspberry 
43: 
Bes the upland fo the view is 
Island locality the bog forest is taken from the bog, a oa the bog 
not so extensively developed as vegetation climbing the slope to a height 
i .5m.; berry Island. 
in other places, all the essential 4.5m; Baspoey = 
features are present. A series of four adjoining units was laid out, 
each 5 m. square, the whole forming a broad section cutting through 
all the societies from the sedge zone to the climax forest (quadrat 9, 
fig. 44). The manner of invasion of the sedge mat by the sphagnum 
is shown. To avoid confusion the distribution of the bog shrubs 
is indicated only in a general way. The trees of the various 
species, their locations, and ages are given in the manner made use 
