384 



LIFE ON THE EARTH 



The digested and soluble substances which are prepared 

 by the leaves are transported to other parts of the plant, 

 where they are combined by the protoplasm of the living 

 cell with other substances contained in the cell sap. Thus 

 the protoplasm itself is able to increase and form new cells 

 as well as other substances, such as woody tissue and oils 

 and resins. In forming these substances the plant requires 



A PINE FOREST 

 From the pitch in these trees turpentine and tar are made. 



oxygen just as animals do. If air is kept from the roots 

 of certain plants, as was seen in Experiment 114, the plants 

 cannot live. 



These food substances which plants make by using the 

 energy supplied by the sun are the bases of all plant and 

 animal life. The sun's energy stored up in the green leaf 

 is the source of all plant and animal energy. If it were 



