756 



seen how the Ininina of the Laminaria hijperborea was sucked into 

 the waves and kept swaying- to and fro when they rushed over 

 tlie rock; it is certainly exposed to a very strong pull here. But 

 Laminaria hijperborea is excellently constructed for resisting this 

 attack of the sea, its stalk being bolh thick and slifT at the bottom 

 but becoming thinner and more elastic towards the apex, so that 

 the flexible lamina can easily follow the motion of the water. It 

 is firmly attached to the bottom by aid of the strong haptera. It is 





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tm. 



Fig. IGO. Laminaria hijperborea with numerous epiphytical Rlwdynienia palmata rising above the surface 

 of the sea at low tide. Illustration from the neighbourhood of Thorshavn. (F. B. phot.) 



a well-known fact to anyone who has dredged among the Lami- 

 naria hijperborea, that only by a very strong pull, or by the teeth of 

 the dredge cutting through the haptera more often through the stalk 

 itself, can the plant be torn from the bottom. I have often tried 

 from a boat to pull up the plants that grew in shallow water, 

 but I have hardly ever succeeded in loosening them without cutting 

 through the haptera. Thus the plant may resist a very strong pull 

 without being detached from the bottom. Its gregarious growth also 

 helps to protect it from the attack of the sea. 



This association covers large areas with an almost unmixed 

 growth of its characteristic alga. It would therefore look very uni- 

 form but for the very luxuriant subvegetation of epiphyles, mainly the 



