LICHEN CRUSTS 



The general scheme of Nature is to cover the whole 

 world with green, so that every ray of sunlight may find a 

 working leaf or green frond ready to welcome it and use it. 

 Nature abhors bare rock, barren sand, and empty water, 

 and never ceases to try to bring it under that beautiful 

 covering of green plants and active vegetable life which 

 supports both man and animals. 



We all know that there is a romance in the story of man's 

 colonies. First the explorer searches out the country ; then 

 the pioneer frontiersman settles and builds his log-hut or 

 rough shanty. Next comes the frontier village, which may 

 perhaps in many years' time become a crowded city where 

 active, valuable work is carried on. 



The story of the colonizing of rocks and stones by plants 

 is just as vividly interesting. These tiny lichens are almost 

 the first pioneers, and prepare the ground for those that 

 follow. Upon that bare rock, life is terribly severe. The 

 frost shatters it, sunshine heats it until it almost burns the 

 hand in summer. Floods of rain or of sleet beat against it, 

 and it may be frozen over for weeks. 



What plant can stand such conditions ? Only these 

 minute, tiny, scarce visible lichen films ! 



Gradually new lichen crusts develop upon it. They 

 cover over the first pioneers ; first they suffocate them and 

 afterwards devour their remains. Nature is very businesslike 

 and severe in her working. The lichen crust may be now 

 about one-sixteenth of an inch thick. It is a very slow 

 process. There is a story of a boy who noticed a patch of 

 lichen near his father's door. He went away to Kamschatka 

 or somewhere and came back a very old man of eighty-five 

 years ; but he found that the lichen patch was just the same 

 size as when he went away. That, however, is just a story ! 



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