A DISPLAY OF ENERGY. 91 



light, the plant-world is busy storing up "energy" 

 for the future wants and possibilities of its life. 

 Think of what this bright- sunlit day means to every 

 leaf, every blade of grass, and every other green thing 

 around you. Under the influence of the light, the 

 living cells of the leaves, aided by the screen of green 

 colouring matter each cell possesses, are absorbing the 

 carbonic-acid gas which the atmosphere is offering 

 them. They are decomposing this gas into the carbon 

 and the oxygen whereof it is composed, and are stor- 

 ing up, or, at least, retaining, the carbon as part of 

 their food, while the oxygen is being set free into 

 the air. 



The carbon will go to aid in forming the starches 

 and sugars and other products of plant-life, and will 

 thus help to build up the living fabric of the plant. 

 Along with the water and minerals absorbed by the 

 root, and a trifle of ammonia which comes chiefly from 

 the soil, the carbonic-acid gas will then build up the 

 plant. All this wealth of leaf and wood, of budding 

 flower and unrolling frond around us, only represents 

 so much non-living matter (or food) elaborated and 

 transmuted by the cells of the plants into vegetable 

 and living tissue. And all the beauty of the summer- 

 flowering, and the richer glory of the later harvest- 

 time, which by and by will make glad the fields that to- 

 day are only showing a faint greenness, will similarly 

 arise out of the transformation of the crude matters of 

 earth and air into the forms and tissues of our plants. 



Now, do you suppose all this building of leaf and 

 stem, this fashioning of bud and flower, is accom- 

 plished without a tremendous expenditure of that 

 energy whereof we have already discoursed ? You 

 can really get no result in the way of work done in 



