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nivalis. These are all of them densely tufted plants with a 

 powerful, deepstriking main-root anchoring them solidly. The 

 individuals are vigorous — the biggest Silene-iwii that I saw 

 was 8 cm in diameter — but on all sides surrounded by the 

 clay which rises 8 — 14 mm above the borders of the tufts 

 (see flg. 7); here and there are tufts, which are inundated 

 barring the inmost shoots, and dead tufts, which have evi- 

 dently once been buried, but have been bared again by abra- 



Fig. S. Young "Rudemark". Л gently inclined flat of clay covered with algæ 

 and Hepaticae with new crevices. Fame Islands. (From photo by Chr. Kruuse). 



sion, are also seen. Here the crack-systems go across the 

 flat (at right angles to the inclination) but are little arched, 

 so that a series of corresponding checks make an arch with 

 the convexity towards the sea. It is evident that the extremes 

 of the clayey flats "trail" against the rocks, so that the move- 

 ment is strongest in the middle. 



Wherever the humidity has kept a little longer in the 

 summer the surface is covered by a blue-gray, abt. 5 mm 

 thick layer of algae with a spare admixture of Anthelia ju- 



1 



