THE HOMEWARD JOURNEY 



bour. The inland-ice is never a safe route ; if anything happens 

 here all results disappear without a trace, and all our toil and 

 stubborn fights for food have then been to no purpose whatever. 

 The precious articles have now been freighted through water 

 and whirlpools, through clefts and over glacier edges, and imme- 

 diately another aspect of the problem must be faced. The col- 

 lections must be brought forward to mankind, and all this 

 makes them doubly precious to one. 



Outside the tent Wulff is sitting preparing the only vege- 

 tation we have found so far here in the Devil's Cleft, grey 

 lichens covering some of the stones. These plants, which grow 

 right on the very stone blocks, are surely unique in contenting 

 themselves with so little, and I therefore get Wulff to tell me 

 something about their biology. 



Lichens are organisms consisting of an alga and a fungus 

 which have united for the benefit of mutual housekeeping. The 

 alga is that shareholder in the limited company which is the sole 

 possessor of an ability to create organic substance out of 

 inorganic matter. The fungus, on the contrary, forms the 

 small aerial roots with which the lichen clings to the substance. 

 The colour of the lichens, as we see it, is a result of the respec- 

 tive colours of the alga and the fungus. 



The lichens are highly impervious to drought, warmth, and 

 cold, and are oidy able to vegetate in turgid condition, but are 

 at rest when it is dry. In this climate they probably vegetate 

 merely a few days in the year, and a patch as big as a penny can 

 often be more than a hundred years old in this neighbourhood, 

 where vegetation is at rest for 350 days of the year. Their chief 

 nourishment they get from the stone through its slight crum- 

 bling, and that cannot be much. The lichen thus is a plant 

 which in all its meanness has eternity before it. 



CAMP 5.— THE MIDGARD SNAKE 



August 9th. — We broke camp on the 9th in the morning, 

 and drove slowly up the great firns of the Devil's Cleft to the 

 north-east. We ascended at an even gradient, groaning under 



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