The Fall of the Leaves 



Other minerals the sap brought from the soil contribute reds 

 and yellows and purples to the colour scheme. As drainage 

 proceeds, with the chemical changes that accompany it, the 

 pageant of autumn colours passes over the woodlands. No 

 weed or grass stem but joins in the carnival of the year. 



Crisp and dry the leaves fall. Among the crystals and 

 granules that remain in their empty chambers there is little but 

 waste that the tree can well afford to be rid of substances that 

 have clogged the leaf and impeded its work. 



We have been mistaken in attributing the gay colours of 

 autumnal foliage to the action of frost. The ripening of the 

 leaves occurs in the season of warm days and frosty nights, but 

 it does not follow that the two phenomena belong together as 

 cause and effect. Frost no doubt hastens the process. But 

 the chemical changes that attend the migration of the carbohy- 

 drates and albuminous materials from the leaf back into twig 

 and trunk and root for safe keeping go on no matter what the 

 weather. 



In countries having a moist atmosphere autumn colours 

 are less vivid. England and our own Pacific coast have nothing 

 to compare with the glory of the foliage in the forests of Canada 

 and the Northeastern States, and with those on the wooded 

 slopes of the Swiss Alps, and along the Rhine and the Danube. 

 Long, dry autumns produce the finest succession of colours. The 

 most brilliant reds and yellows often appear long before the first 

 frost. Cold rains of long duration wash the colours out of the 

 landscape, sometimes spoiling everything before October. A 

 sharp freeze before the leaves expect it often cuts them off before 

 they are ripe. They stiffen and fall, and are wet and limp next 

 day, as if they had been scalded; all their rich cell substance lost 

 to the tree, except as they form a mulch about its roots. But 

 no tree can afford so expensive a fertiliser, and happily they are 

 not often caught unawares. 



Under the trees the dead leaves lie, forming with the snow 

 a protective blanket for the roots. In spring the rains will leach 

 out their mineral substance and add it to the soil. The abundant 

 lime in dead leaves is active in the formation of humus, which 

 is decayed vegetable m.atter. We call it "leaf mould." So 

 even the waste portions have their effectual work to do for 

 the tree's good. 



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