262 SYLVAN WINTEE. 



replaced, and it is in this direction that the wise 

 economy of Nature is exercised, and provision is 

 made for returning to the plant just those par- 

 ticular elements needed to supply its particular 

 or individual requirements. 



How admirably this purpose is fulfilled, will be 

 suggested by a visit to the untouched ' floor ' of 

 a forest. There lie, thickly scattered, dead and 

 dry, the hosts of leaves ; the dead and withered 

 blossoms, and the ungathered and shrivelled 

 fruit, shorn indeed of the gloss and beauty of 

 summer, shorn even of the exquisite tints of 

 autumn, but rich still in all those essential 

 constituents which make up the glory and beauty 

 of the seasons of warmth and genial sunshine. 

 Except their moisture, which is mostly gone with 

 those gases which compose it, the dead leaves 

 embody nearly all the plant-food which the 

 living ones contained : carbonic acid, lime, mag- 

 nesia, phosphoric acid, potash, silicic acid, soda, 

 and sulphuric acid, with sometimes metallic 

 oxides of aluminium, copper, or iron, and it may 

 be bromine, fluorine, and iodine, and sometimes 

 salts. The evaporated moisture is soon returned 



