LICHENS 



Sometimes they are of the richest deep crimson or lake, 

 set against a pure snow-white crust. Those of Lecanora 

 vitellina are, though tiny, a brilliant yellow, and quite 

 startling when first one notices them. Many of these con- 

 trasts and shades are never used by artists, and even from 

 the mere artistic point of view they have great interest. 



But if, after spending a few minutes in carefully looking 

 over the rocks at a distance of six or seven inches, one stands 

 up and goes back to four or five feet away, the whole of this 

 colour scheme fades away and there is only the monotonous 

 indeterminate grey or neutral tint of the wall. 



Now why is this ? Why should these delicate and exquis- 

 ite shades be wasted on such minute and scarcely distinguish- 

 able forms ? 



There are always two sides from which one can look at 

 any subject, namely the inside and the outside. 



From the inside (that is from the point of view of the 

 little lichen itself) these colours are decidedly useful. Small 

 insects crawl about on such walls or hover a few inches in 

 front of them, and to those insects these cups will be as con- 

 spicuous and attractive as a scarlet geranium is to ourselves. 



Just as we habitually go to look at a geranium, so those 

 insects fly towards the cups and crawl about on them. Then 

 when the spores and dust of the lichen begin to stick in 

 their hairs and feet, they go to a bare place and clean or 

 brush them off. Thus the spores and dust are carried to a 

 new part of the rock, where they will grow if they can find 

 an unoccupied place. The taste in colour of these insects, 

 moreover, is apparently not very different from that of man. 



But perhaps a still more interesting point of view is that 

 from the outside. Why are those lichens there ? What are 

 they doing, and are they of any use .'' 



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