104 THE GARDEN OF EARTH 



" How does the wood come to be there at all ? " one 

 may ask; and perhaps you would answer, "Why, it 

 grows ! It is the trunk itself." Yes, it is ; but it has 

 to be made. It has to be built up, year by year, within 

 and by itself, layer upon layer. And even there, 

 though in a sense the leaves do not carry on the work, 

 it is more or less due to them. For if they did not 

 faithfully perform their share, by changing the raw 

 sap into finished sap and sending it back through count- 

 less channels to nourish every part of the tree, no wood 

 could grow. 



Other materials, such as rubber, are made in the 

 stems of trees, and not actually by the leaves; and 

 the same may be said of seeds and fruits, formed in and 

 by the flowers. Yet in all these cases the leaves lend 

 a hand. 



From early morning till evening they are at it inces- 

 santly ; gathering air and water ; choosing the materials 

 that they need; working all up under the sun's rays; 

 and turning out in the end that which it is their duty to 

 produce. 



Then at last the completed sap is ready. And 

 the different uses of it, made by different plants — the 

 varieties of substances brought forth — are simply 

 amazing. 



Some serve for the food of the growing plant itself. 

 Some are meant for the support of young plants in the 

 future. Very many are food for animals and men. 



Indeed, the greater amount of food, upon which our 

 lives depend, comes to us in this way. We get it straight 

 from plants by eating fruits and vegetables, roots and 



