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to the protection of the plants against evaporation they are likely 

 to be regarded as weekly xeromorphous. 



The shore is formed on the western, northern and eastern 

 coast of great stones and is here quite destitute of vegetation. 

 Only here and there a single sample of Naumburgia or Ly thrum 

 salicaria shoots up between the stones. The stone-reef, which 

 bounds the island, is higher than the interior of the island." Only 

 in the south the bogged interior of the island is gently sloping 

 into the stony bottom of the lake. 



Just east of this spot the stone-reef is very low and can 

 be set under water at high stand of the water. Here grow 

 some small shrubs of alder and several specimens of Myrica. 

 Among the shrubs grow numerous tall herbs, whose leaves and 

 flowers promine to the same height or higher than the branches 

 of the Myrica. As the herbs are as high as the shrubs, the for- 

 mation cannot be regarded as consisting of more stories. The 

 season, in which the upper layer is of biological importance for 

 the under story is chiefly the summer. Table I shows the num- 

 bers of frequency of the species of this formation. Hereof results 

 that it is to be regarded as a formation of mesomorphous 

 or weakly xeromorphous, diageic herbs, with defolia- 

 tion in winter. The soil is stony with loose mouldish mud be- 

 tween the stones. 



Along the other coasts the stone-reef wears a row of alder- 

 wood. Only in a small space in north-east the wood fails and 

 is replaced by a narrow row of low shrubs of Rhamnus. In a few 

 spots on the western coast interruptions of the wood are also 

 found, so that the prairie of the interior is directly facing the shore. 



The wood is formed by a single row of trees. To the shore the 

 branches reach the water. Under the alders Rhamnus frangula grow 

 everywhere, so that the wood has three stories. The shrubs of 

 Rhamnus in connection with the lowest branches of the alders 

 form a dense and shading mass of branches towards the lake. 

 Somewhere on the western coast a few shrubs of Myrica are found 

 outside the alders. On the inside towards the low interior of the 

 island the wood is bordered by a row of low shrubs of Rhamnus, 

 which, where they are most vigorous, are effecting that the nar- 

 row strip of wood gets very shady, so that it locally is very dark 

 in the bottom. On several spots on the eastern coast is found 

 moreover a narrow row of Vaccinium uliginosum between the 



