THE STRUGGLE FOR LIGHT 47 



on the floor of a wood where life depended on utter acquisi- 

 tiveness of the small rations of sunshine. Plants of course 

 differ immensely in their need of light. The grass, the else 

 invincible grass, which makes its way to the roofs and 

 carpets a neglected roadway in two seasons, pales to a 

 jaundice colour in a twilight situation, and dies out at once. 

 The kexes, especially the lesser chervil, grow a splendid dark 

 green under the shade of very thick hedges, and seem to suffer 

 not at all. St. John's wort, it is generally supposed, delights 

 in shade, and has clothed the ground under many a garden 

 tree with thick cover and flowers as gold and sunny as the 

 sun. But its delight in such places is in part due merely to 

 its earliness. When its leaves begin the canopy of the tree is 

 not yet spread nor the light intercepted. But doubtless it 

 can endure gloom, as may that lusty and at times light-loving 

 plant the periwinkle. It is a little surprising too that the 

 beech, which of all trees is most destructive of life beneath its 

 shadow, will grow in coppice shape under trees that will shade 

 other bushes to death. Happily no place is ever quite bare of 

 the green things whose life is light. Deep mosses mimicking 

 now trees in their form, now jewels in their tints, carpet the 

 woods. On the roofs of dark caves by the coast hang green 

 the ribbon leaves of asplenium marinum, which, like the 

 mosses, steals light out of water and stores reflected rays. 



We all mark the full leafage seeking sunlight and storing 

 its energy. But flowers and fruit have as vital a need of sun- 

 shine as the leaves. The sun is needed at all stages. We 

 just begin to understand that flowers are only fructified when 

 the sun is hot. The fertilising of the flowers of clover and 

 hazel and doubtless many others is a midday function, when 

 the full energy of the sun is directed upon the pollen. Even 

 when fertilised the seed or fruit has not its full strength to 

 resist frost unless it enjoys a bout of sun. When well set 

 it retires for a while in some obscurity behind the leaves and 



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