CHAPTER XXXV 



PLANTS THAT HAVE NO FLOWERS 



LICHENS MOSSES FERNS 



LICHENS 



IF we could look back into the distant past history of our earth, 

 and picture to ourselves the vegetation that clothed the dry land 

 at the time when what we now dig up as coal was green and alive, 

 we should be struck by the absence of flowering plants. In the 

 place of trees, shrubs, and herbs which now cover our country side, 

 we know that mosses and ferns existed, and rush-like plants, many 

 of them vastly larger than their present day descendants. In fact, 

 the science of geology teaches us that flowering plants did not 

 appear until long afterwards. They are now the dominant group 

 in nearly all parts of the earth's surface, except at high altitudes, 

 but it seems not improbable that if, as astronomers tell us, our 

 earth will one day be like the moon, its vegetation will once more, 

 before life becomes extinct, consist solely of the flowerless plants. 



Of these, perhaps, none are more interesting than the lichens, 

 not only because of their double nature, but because they are 

 essentially the vegetation of rocky and stony ground. Let us 

 imagine a volcano which has recently erupted and thrown up a 

 vast mass of liquid lava to the surface. This not only happens 

 nowadays, but doubtless was far more widespread in former ages. 



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