-32- 
oaespitosa (L.) Beauv. (huirgrass). The former was found 
growing within 3 dm. of the water; the latter is undoubtedly 
the commonest grass growing in the crevioes of the shore 
rooks. 
Pig. 14 represents a typical situation for crevice 
vegetation. Such a habitat enables even woody plants to 
come in very early. In the foreground is shown a large 
specimen of ninebark ( Physooarpus opulifolius ) and in the 
background a small speciman of mountain ash ( :pyr us sitchensis j♦ 
The former has assumed more or less of the krummholz form of 
growth, especially on the lake or windward side; its habit 
of growth thus makes it more efficient as a conserver of 
soil and moisture. 
The rate of succession along the outer shore is evi¬ 
dently not to be measured by the character of the plant life, 
the highest forms being found with the lowest. As before 
indicated, this rate is exceedingly slow, due to the severity 
of the situation. In spite of this, a large number of species 
are found. One group may be olassod as typical crevice plants. 
Among these, besides those mentioned, are Campanula rotund! - 
folia L. (bluebell), Aster Faxoni Porter, Soneoio Balsamitae 
Muhl. (groundsel), Fragaria virgin!ana Duchesne (strawberry), 
Achillea Millefolium L. (yarrow), Bquisetum arvense L. (horse¬ 
tail ). 
