84 THE GARDEN OF EARTH 



They take in hand the raw materials, which are 

 dissolved in water and brought to them from the soil, 

 together with the gases which they receive from the air ; 

 and they work up these materials and gases into what 

 is known as " Organic Substance " that is, into such a 

 substance that LIFE CAN WORK IN AND THROUGH IT. 



Life cannot work through all kinds of substance. It 

 cannot, for example, through marble or granite. But 

 when the leaves have prepared this " organic sub- 

 stance " it has become fit for food of animals and men, 

 for Life can enter into it and can use it. 



Each day with early dawn the toil of the green sub- 

 stance of leaves begins. At night, in hours of darkness, 

 it rests; but no sooner does sunlight return than it is 

 once more hard at work. 



How many leaves would you imagine to be on a tree ? 

 Counting is no easy matter with one of any consider- 

 able size, they cluster in such dense masses. But a 

 reckoning was made with an Oak, probably a large 

 tree, for the result gave about seven hundred thousand 

 leaves ! What, then, must be the multitudes in a wood, 

 in a forest, in the whole world ? 



Not only are their numbers enormous, but their 

 kinds and shapes and varieties are endless. Some are 

 large, some small; some are thick, some almost trans- 

 parent ; some are strong, some fragile ; some are long and 

 narrow, some short and broad ; in fact, every imaginable 

 description of make may be found. 



And they grow so differently : some in pairs, one 

 opposite another; some alternately; some in circles or 

 " whorls " around the stem. 



